From cc03638df20acbec5d0d0d9e07234aadde9e698d Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Wed, 27 Apr 2011 15:26:56 -0700 Subject: mm: check if PTE is already allocated during page fault With transparent hugepage support, handle_mm_fault() has to be careful that a normal PMD has been established before handling a PTE fault. To achieve this, it used __pte_alloc() directly instead of pte_alloc_map as pte_alloc_map is unsafe to run against a huge PMD. pte_offset_map() is called once it is known the PMD is safe. pte_alloc_map() is smart enough to check if a PTE is already present before calling __pte_alloc but this check was lost. As a consequence, PTEs may be allocated unnecessarily and the page table lock taken. Thi useless PTE does get cleaned up but it's a performance hit which is visible in page_test from aim9. This patch simply re-adds the check normally done by pte_alloc_map to check if the PTE needs to be allocated before taking the page table lock. The effect is noticable in page_test from aim9. AIM9 2.6.38-vanilla 2.6.38-checkptenone creat-clo 446.10 ( 0.00%) 424.47 (-5.10%) page_test 38.10 ( 0.00%) 42.04 ( 9.37%) brk_test 52.45 ( 0.00%) 51.57 (-1.71%) exec_test 382.00 ( 0.00%) 456.90 (16.39%) fork_test 60.11 ( 0.00%) 67.79 (11.34%) MMTests Statistics: duration Total Elapsed Time (seconds) 611.90 612.22 (While this affects 2.6.38, it is a performance rather than a functional bug and normally outside the rules -stable. While the big performance differences are to a microbench, the difference in fork and exec performance may be significant enough that -stable wants to consider the patch) Reported-by: Raz Ben Yehuda Signed-off-by: Mel Gorman Reviewed-by: Rik van Riel Reviewed-by: Andrea Arcangeli Reviewed-by: Minchan Kim Acked-by: Johannes Weiner Cc: [2.6.38.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index ce22a250926f..607098d47e74 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3396,7 +3396,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, * run pte_offset_map on the pmd, if an huge pmd could * materialize from under us from a different thread. */ - if (unlikely(__pte_alloc(mm, vma, pmd, address))) + if (unlikely(pmd_none(*pmd)) && __pte_alloc(mm, vma, pmd, address)) return VM_FAULT_OOM; /* if an huge pmd materialized from under us just retry later */ if (unlikely(pmd_trans_huge(*pmd))) -- cgit v1.2.3 From a1fde08c74e90accd62d4cfdbf580d2ede938fe7 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 4 May 2011 21:30:28 -0700 Subject: VM: skip the stack guard page lookup in get_user_pages only for mlock The logic in __get_user_pages() used to skip the stack guard page lookup whenever the caller wasn't interested in seeing what the actual page was. But Michel Lespinasse points out that there are cases where we don't care about the physical page itself (so 'pages' may be NULL), but do want to make sure a page is mapped into the virtual address space. So using the existence of the "pages" array as an indication of whether to look up the guard page or not isn't actually so great, and we really should just use the FOLL_MLOCK bit. But because that bit was only set for the VM_LOCKED case (and not all vma's necessarily have it, even for mlock()), we couldn't do that originally. Fix that by moving the VM_LOCKED check deeper into the call-chain, which actually simplifies many things. Now mlock() gets simpler, and we can also check for FOLL_MLOCK in __get_user_pages() and the code ends up much more straightforward. Reported-and-reviewed-by: Michel Lespinasse Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- mm/memory.c | 7 +++---- mm/mlock.c | 5 +---- 2 files changed, 4 insertions(+), 8 deletions(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index 607098d47e74..27f425378112 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1359,7 +1359,7 @@ split_fallthrough: */ mark_page_accessed(page); } - if (flags & FOLL_MLOCK) { + if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) { /* * The preliminary mapping check is mainly to avoid the * pointless overhead of lock_page on the ZERO_PAGE @@ -1552,10 +1552,9 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, } /* - * If we don't actually want the page itself, - * and it's the stack guard page, just skip it. + * For mlock, just skip the stack guard page. */ - if (!pages && stack_guard_page(vma, start)) + if ((gup_flags & FOLL_MLOCK) && stack_guard_page(vma, start)) goto next_page; do { diff --git a/mm/mlock.c b/mm/mlock.c index 6b55e3efe0df..516b2c2ddd5a 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -162,7 +162,7 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma, VM_BUG_ON(end > vma->vm_end); VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); - gup_flags = FOLL_TOUCH; + gup_flags = FOLL_TOUCH | FOLL_MLOCK; /* * We want to touch writable mappings with a write fault in order * to break COW, except for shared mappings because these don't COW @@ -178,9 +178,6 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma, if (vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) gup_flags |= FOLL_FORCE; - if (vma->vm_flags & VM_LOCKED) - gup_flags |= FOLL_MLOCK; - return __get_user_pages(current, mm, addr, nr_pages, gup_flags, NULL, NULL, nonblocking); } -- cgit v1.2.3 From a09a79f66874c905af35d5bb5e5f2fdc7b6b894d Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 9 May 2011 13:01:09 +0200 Subject: Don't lock guardpage if the stack is growing up Linux kernel excludes guard page when performing mlock on a VMA with down-growing stack. However, some architectures have up-growing stack and locking the guard page should be excluded in this case too. This patch fixes lvm2 on PA-RISC (and possibly other architectures with up-growing stack). lvm2 calculates number of used pages when locking and when unlocking and reports an internal error if the numbers mismatch. [ Patch changed fairly extensively to also fix /proc//maps for the grows-up case, and to move things around a bit to clean it all up and share the infrstructure with the /proc bits. Tested on ia64 that has both grow-up and grow-down segments - Linus ] Signed-off-by: Mikulas Patocka Tested-by: Tony Luck Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- fs/proc/task_mmu.c | 12 +++++++----- include/linux/mm.h | 24 +++++++++++++++++++++++- mm/memory.c | 16 +++++++--------- 3 files changed, 37 insertions(+), 15 deletions(-) (limited to 'mm/memory.c') diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2e7addfd9803..318d8654989b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -214,7 +214,7 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) int flags = vma->vm_flags; unsigned long ino = 0; unsigned long long pgoff = 0; - unsigned long start; + unsigned long start, end; dev_t dev = 0; int len; @@ -227,13 +227,15 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) /* We don't show the stack guard page in /proc/maps */ start = vma->vm_start; - if (vma->vm_flags & VM_GROWSDOWN) - if (!vma_stack_continue(vma->vm_prev, vma->vm_start)) - start += PAGE_SIZE; + if (stack_guard_page_start(vma, start)) + start += PAGE_SIZE; + end = vma->vm_end; + if (stack_guard_page_end(vma, end)) + end -= PAGE_SIZE; seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n", start, - vma->vm_end, + end, flags & VM_READ ? 'r' : '-', flags & VM_WRITE ? 'w' : '-', flags & VM_EXEC ? 'x' : '-', diff --git a/include/linux/mm.h b/include/linux/mm.h index 2348db26bc3d..6507dde38b16 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1011,11 +1011,33 @@ int set_page_dirty_lock(struct page *page); int clear_page_dirty_for_io(struct page *page); /* Is the vma a continuation of the stack vma above it? */ -static inline int vma_stack_continue(struct vm_area_struct *vma, unsigned long addr) +static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr) { return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN); } +static inline int stack_guard_page_start(struct vm_area_struct *vma, + unsigned long addr) +{ + return (vma->vm_flags & VM_GROWSDOWN) && + (vma->vm_start == addr) && + !vma_growsdown(vma->vm_prev, addr); +} + +/* Is the vma a continuation of the stack vma below it? */ +static inline int vma_growsup(struct vm_area_struct *vma, unsigned long addr) +{ + return vma && (vma->vm_start == addr) && (vma->vm_flags & VM_GROWSUP); +} + +static inline int stack_guard_page_end(struct vm_area_struct *vma, + unsigned long addr) +{ + return (vma->vm_flags & VM_GROWSUP) && + (vma->vm_end == addr) && + !vma_growsup(vma->vm_next, addr); +} + extern unsigned long move_page_tables(struct vm_area_struct *vma, unsigned long old_addr, struct vm_area_struct *new_vma, unsigned long new_addr, unsigned long len); diff --git a/mm/memory.c b/mm/memory.c index 27f425378112..61e66f026563 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1412,9 +1412,8 @@ no_page_table: static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long addr) { - return (vma->vm_flags & VM_GROWSDOWN) && - (vma->vm_start == addr) && - !vma_stack_continue(vma->vm_prev, addr); + return stack_guard_page_start(vma, addr) || + stack_guard_page_end(vma, addr+PAGE_SIZE); } /** @@ -1551,12 +1550,6 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, continue; } - /* - * For mlock, just skip the stack guard page. - */ - if ((gup_flags & FOLL_MLOCK) && stack_guard_page(vma, start)) - goto next_page; - do { struct page *page; unsigned int foll_flags = gup_flags; @@ -1573,6 +1566,11 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, int ret; unsigned int fault_flags = 0; + /* For mlock, just skip the stack guard page. */ + if (foll_flags & FOLL_MLOCK) { + if (stack_guard_page(vma, start)) + goto next_page; + } if (foll_flags & FOLL_WRITE) fault_flags |= FAULT_FLAG_WRITE; if (nonblocking) -- cgit v1.2.3 From d05f3169c0fbca16132ec7c2be71685c6de638b5 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Tue, 24 May 2011 17:11:44 -0700 Subject: mm: make expand_downwards() symmetrical with expand_upwards() Currently we have expand_upwards exported while expand_downwards is accessible only via expand_stack or expand_stack_downwards. check_stack_guard_page is a nice example of the asymmetry. It uses expand_stack for VM_GROWSDOWN while expand_upwards is called for VM_GROWSUP case. Let's clean this up by exporting both functions and make those names consistent. Let's use expand_{upwards,downwards} because expanding doesn't always involve stack manipulation (an example is ia64_do_page_fault which uses expand_upwards for registers backing store expansion). expand_downwards has to be defined for both CONFIG_STACK_GROWS{UP,DOWN} because get_arg_page calls the downwards version in the early process initialization phase for growsup configuration. Signed-off-by: Michal Hocko Acked-by: Hugh Dickins Cc: James Bottomley Cc: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/exec.c | 2 +- include/linux/mm.h | 8 +++++--- mm/memory.c | 2 +- mm/mmap.c | 7 +------ 4 files changed, 8 insertions(+), 11 deletions(-) (limited to 'mm/memory.c') diff --git a/fs/exec.c b/fs/exec.c index c1cf372f17a7..e276d5e0abb9 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -200,7 +200,7 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, #ifdef CONFIG_STACK_GROWSUP if (write) { - ret = expand_stack_downwards(bprm->vma, pos); + ret = expand_downwards(bprm->vma, pos); if (ret < 0) return NULL; } diff --git a/include/linux/mm.h b/include/linux/mm.h index e173cd297d88..d2948af126ca 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1518,15 +1518,17 @@ unsigned long ra_submit(struct file_ra_state *ra, struct address_space *mapping, struct file *filp); -/* Do stack extension */ +/* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */ extern int expand_stack(struct vm_area_struct *vma, unsigned long address); + +/* CONFIG_STACK_GROWSUP still needs to to grow downwards at some places */ +extern int expand_downwards(struct vm_area_struct *vma, + unsigned long address); #if VM_GROWSUP extern int expand_upwards(struct vm_area_struct *vma, unsigned long address); #else #define expand_upwards(vma, address) do { } while (0) #endif -extern int expand_stack_downwards(struct vm_area_struct *vma, - unsigned long address); /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */ extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr); diff --git a/mm/memory.c b/mm/memory.c index 61e66f026563..4c6ea10f3d18 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2966,7 +2966,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo if (prev && prev->vm_end == address) return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM; - expand_stack(vma, address - PAGE_SIZE); + expand_downwards(vma, address - PAGE_SIZE); } if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) { struct vm_area_struct *next = vma->vm_next; diff --git a/mm/mmap.c b/mm/mmap.c index e76f8d752884..adb12527fd0e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1774,7 +1774,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) /* * vma is the first one with address < vma->vm_start. Have to extend vma. */ -static int expand_downwards(struct vm_area_struct *vma, +int expand_downwards(struct vm_area_struct *vma, unsigned long address) { int error; @@ -1821,11 +1821,6 @@ static int expand_downwards(struct vm_area_struct *vma, return error; } -int expand_stack_downwards(struct vm_area_struct *vma, unsigned long address) -{ - return expand_downwards(vma, address); -} - #ifdef CONFIG_STACK_GROWSUP int expand_stack(struct vm_area_struct *vma, unsigned long address) { -- cgit v1.2.3 From d16dfc550f5326a4000f3322582a7c05dec91d7a Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:11:45 -0700 Subject: mm: mmu_gather rework Rework the existing mmu_gather infrastructure. The direct purpose of these patches was to allow preemptible mmu_gather, but even without that I think these patches provide an improvement to the status quo. The first 9 patches rework the mmu_gather infrastructure. For review purpose I've split them into generic and per-arch patches with the last of those a generic cleanup. The next patch provides generic RCU page-table freeing, and the followup is a patch converting s390 to use this. I've also got 4 patches from DaveM lined up (not included in this series) that uses this to implement gup_fast() for sparc64. Then there is one patch that extends the generic mmu_gather batching. After that follow the mm preemptibility patches, these make part of the mm a lot more preemptible. It converts i_mmap_lock and anon_vma->lock to mutexes which together with the mmu_gather rework makes mmu_gather preemptible as well. Making i_mmap_lock a mutex also enables a clean-up of the truncate code. This also allows for preemptible mmu_notifiers, something that XPMEM I think wants. Furthermore, it removes the new and universially detested unmap_mutex. This patch: Remove the first obstacle towards a fully preemptible mmu_gather. The current scheme assumes mmu_gather is always done with preemption disabled and uses per-cpu storage for the page batches. Change this to try and allocate a page for batching and in case of failure, use a small on-stack array to make some progress. Preemptible mmu_gather is desired in general and usable once i_mmap_lock becomes a mutex. Doing it before the mutex conversion saves us from having to rework the code by moving the mmu_gather bits inside the pte_lock. Also avoid flushing the tlb batches from under the pte lock, this is useful even without the i_mmap_lock conversion as it significantly reduces pte lock hold times. [akpm@linux-foundation.org: fix comment tpyo] Signed-off-by: Peter Zijlstra Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Reviewed-by: KAMEZAWA Hiroyuki Acked-by: Hugh Dickins Acked-by: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/exec.c | 10 ++--- include/asm-generic/tlb.h | 96 ++++++++++++++++++++++++++++++++++------------- include/linux/mm.h | 2 +- mm/memory.c | 46 +++++++++++------------ mm/mmap.c | 18 ++++----- 5 files changed, 107 insertions(+), 65 deletions(-) (limited to 'mm/memory.c') diff --git a/fs/exec.c b/fs/exec.c index e276d5e0abb9..936f5776655c 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -600,7 +600,7 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) unsigned long length = old_end - old_start; unsigned long new_start = old_start - shift; unsigned long new_end = old_end - shift; - struct mmu_gather *tlb; + struct mmu_gather tlb; BUG_ON(new_start > new_end); @@ -626,12 +626,12 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) return -ENOMEM; lru_add_drain(); - tlb = tlb_gather_mmu(mm, 0); + tlb_gather_mmu(&tlb, mm, 0); if (new_end > old_start) { /* * when the old and new regions overlap clear from new_end. */ - free_pgd_range(tlb, new_end, old_end, new_end, + free_pgd_range(&tlb, new_end, old_end, new_end, vma->vm_next ? vma->vm_next->vm_start : 0); } else { /* @@ -640,10 +640,10 @@ static int shift_arg_pages(struct vm_area_struct *vma, unsigned long shift) * have constraints on va-space that make this illegal (IA64) - * for the others its just a little faster. */ - free_pgd_range(tlb, old_start, old_end, new_end, + free_pgd_range(&tlb, old_start, old_end, new_end, vma->vm_next ? vma->vm_next->vm_start : 0); } - tlb_finish_mmu(tlb, new_end, old_end); + tlb_finish_mmu(&tlb, new_end, old_end); /* * Shrink the vma to just the new range. Always succeeds. diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index e43f9766259f..2d3547c84235 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -5,6 +5,8 @@ * Copyright 2001 Red Hat, Inc. * Based on code from mm/memory.c Copyright Linus Torvalds and others. * + * Copyright 2011 Red Hat, Inc., Peter Zijlstra + * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version @@ -22,51 +24,71 @@ * and page free order so much.. */ #ifdef CONFIG_SMP - #ifdef ARCH_FREE_PTR_NR - #define FREE_PTR_NR ARCH_FREE_PTR_NR - #else - #define FREE_PTE_NR 506 - #endif #define tlb_fast_mode(tlb) ((tlb)->nr == ~0U) #else - #define FREE_PTE_NR 1 #define tlb_fast_mode(tlb) 1 #endif +/* + * If we can't allocate a page to make a big batch of page pointers + * to work on, then just handle a few from the on-stack structure. + */ +#define MMU_GATHER_BUNDLE 8 + /* struct mmu_gather is an opaque type used by the mm code for passing around * any data needed by arch specific code for tlb_remove_page. */ struct mmu_gather { struct mm_struct *mm; unsigned int nr; /* set to ~0U means fast mode */ + unsigned int max; /* nr < max */ unsigned int need_flush;/* Really unmapped some ptes? */ unsigned int fullmm; /* non-zero means full mm flush */ - struct page * pages[FREE_PTE_NR]; +#ifdef HAVE_ARCH_MMU_GATHER + struct arch_mmu_gather arch; +#endif + struct page **pages; + struct page *local[MMU_GATHER_BUNDLE]; }; -/* Users of the generic TLB shootdown code must declare this storage space. */ -DECLARE_PER_CPU(struct mmu_gather, mmu_gathers); +static inline void __tlb_alloc_page(struct mmu_gather *tlb) +{ + unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + + if (addr) { + tlb->pages = (void *)addr; + tlb->max = PAGE_SIZE / sizeof(struct page *); + } +} /* tlb_gather_mmu - * Return a pointer to an initialized struct mmu_gather. + * Called to initialize an (on-stack) mmu_gather structure for page-table + * tear-down from @mm. The @fullmm argument is used when @mm is without + * users and we're going to destroy the full address space (exit/execve). */ -static inline struct mmu_gather * -tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush) +static inline void +tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) { - struct mmu_gather *tlb = &get_cpu_var(mmu_gathers); - tlb->mm = mm; - /* Use fast mode if only one CPU is online */ - tlb->nr = num_online_cpus() > 1 ? 0U : ~0U; + tlb->max = ARRAY_SIZE(tlb->local); + tlb->pages = tlb->local; + + if (num_online_cpus() > 1) { + tlb->nr = 0; + __tlb_alloc_page(tlb); + } else /* Use fast mode if only one CPU is online */ + tlb->nr = ~0U; - tlb->fullmm = full_mm_flush; + tlb->fullmm = fullmm; - return tlb; +#ifdef HAVE_ARCH_MMU_GATHER + tlb->arch = ARCH_MMU_GATHER_INIT; +#endif } static inline void -tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +tlb_flush_mmu(struct mmu_gather *tlb) { if (!tlb->need_flush) return; @@ -75,6 +97,13 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) if (!tlb_fast_mode(tlb)) { free_pages_and_swap_cache(tlb->pages, tlb->nr); tlb->nr = 0; + /* + * If we are using the local on-stack array of pages for MMU + * gather, try allocating an off-stack array again as we have + * recently freed pages. + */ + if (tlb->pages == tlb->local) + __tlb_alloc_page(tlb); } } @@ -85,29 +114,42 @@ tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) static inline void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) { - tlb_flush_mmu(tlb, start, end); + tlb_flush_mmu(tlb); /* keep the page table cache within bounds */ check_pgt_cache(); - put_cpu_var(mmu_gathers); + if (tlb->pages != tlb->local) + free_pages((unsigned long)tlb->pages, 0); } -/* tlb_remove_page +/* __tlb_remove_page * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while * handling the additional races in SMP caused by other CPUs caching valid - * mappings in their TLBs. + * mappings in their TLBs. Returns the number of free page slots left. + * When out of page slots we must call tlb_flush_mmu(). */ -static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) +static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) { tlb->need_flush = 1; if (tlb_fast_mode(tlb)) { free_page_and_swap_cache(page); - return; + return 1; /* avoid calling tlb_flush_mmu() */ } tlb->pages[tlb->nr++] = page; - if (tlb->nr >= FREE_PTE_NR) - tlb_flush_mmu(tlb, 0, 0); + VM_BUG_ON(tlb->nr > tlb->max); + + return tlb->max - tlb->nr; +} + +/* tlb_remove_page + * Similar to __tlb_remove_page but will call tlb_flush_mmu() itself when + * required. + */ +static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + if (!__tlb_remove_page(tlb, page)) + tlb_flush_mmu(tlb); } /** diff --git a/include/linux/mm.h b/include/linux/mm.h index d2948af126ca..ffcce9bf2b54 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -906,7 +906,7 @@ int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, unsigned long size); unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *); -unsigned long unmap_vmas(struct mmu_gather **tlb, +unsigned long unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long start_addr, unsigned long end_addr, unsigned long *nr_accounted, struct zap_details *); diff --git a/mm/memory.c b/mm/memory.c index 4c6ea10f3d18..19b2d44de9f0 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -912,12 +912,13 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, long *zap_work, struct zap_details *details) { struct mm_struct *mm = tlb->mm; + int force_flush = 0; pte_t *pte; spinlock_t *ptl; int rss[NR_MM_COUNTERS]; init_rss_vec(rss); - +again: pte = pte_offset_map_lock(mm, pmd, addr, &ptl); arch_enter_lazy_mmu_mode(); do { @@ -974,7 +975,9 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, page_remove_rmap(page); if (unlikely(page_mapcount(page) < 0)) print_bad_pte(vma, addr, ptent, page); - tlb_remove_page(tlb, page); + force_flush = !__tlb_remove_page(tlb, page); + if (force_flush) + break; continue; } /* @@ -1001,6 +1004,18 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, arch_leave_lazy_mmu_mode(); pte_unmap_unlock(pte - 1, ptl); + /* + * mmu_gather ran out of room to batch pages, we break out of + * the PTE lock to avoid doing the potential expensive TLB invalidate + * and page-free while holding it. + */ + if (force_flush) { + force_flush = 0; + tlb_flush_mmu(tlb); + if (addr != end) + goto again; + } + return addr; } @@ -1121,17 +1136,14 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb, * ensure that any thus-far unmapped pages are flushed before unmap_vmas() * drops the lock and schedules. */ -unsigned long unmap_vmas(struct mmu_gather **tlbp, +unsigned long unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start_addr, unsigned long end_addr, unsigned long *nr_accounted, struct zap_details *details) { long zap_work = ZAP_BLOCK_SIZE; - unsigned long tlb_start = 0; /* For tlb_finish_mmu */ - int tlb_start_valid = 0; unsigned long start = start_addr; spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL; - int fullmm = (*tlbp)->fullmm; struct mm_struct *mm = vma->vm_mm; mmu_notifier_invalidate_range_start(mm, start_addr, end_addr); @@ -1152,11 +1164,6 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp, untrack_pfn_vma(vma, 0, 0); while (start != end) { - if (!tlb_start_valid) { - tlb_start = start; - tlb_start_valid = 1; - } - if (unlikely(is_vm_hugetlb_page(vma))) { /* * It is undesirable to test vma->vm_file as it @@ -1177,7 +1184,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp, start = end; } else - start = unmap_page_range(*tlbp, vma, + start = unmap_page_range(tlb, vma, start, end, &zap_work, details); if (zap_work > 0) { @@ -1185,19 +1192,13 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp, break; } - tlb_finish_mmu(*tlbp, tlb_start, start); - if (need_resched() || (i_mmap_lock && spin_needbreak(i_mmap_lock))) { - if (i_mmap_lock) { - *tlbp = NULL; + if (i_mmap_lock) goto out; - } cond_resched(); } - *tlbp = tlb_gather_mmu(vma->vm_mm, fullmm); - tlb_start_valid = 0; zap_work = ZAP_BLOCK_SIZE; } } @@ -1217,16 +1218,15 @@ unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *details) { struct mm_struct *mm = vma->vm_mm; - struct mmu_gather *tlb; + struct mmu_gather tlb; unsigned long end = address + size; unsigned long nr_accounted = 0; lru_add_drain(); - tlb = tlb_gather_mmu(mm, 0); + tlb_gather_mmu(&tlb, mm, 0); update_hiwater_rss(mm); end = unmap_vmas(&tlb, vma, address, end, &nr_accounted, details); - if (tlb) - tlb_finish_mmu(tlb, address, end); + tlb_finish_mmu(&tlb, address, end); return end; } diff --git a/mm/mmap.c b/mm/mmap.c index adb12527fd0e..40d49986e714 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1903,17 +1903,17 @@ static void unmap_region(struct mm_struct *mm, unsigned long start, unsigned long end) { struct vm_area_struct *next = prev? prev->vm_next: mm->mmap; - struct mmu_gather *tlb; + struct mmu_gather tlb; unsigned long nr_accounted = 0; lru_add_drain(); - tlb = tlb_gather_mmu(mm, 0); + tlb_gather_mmu(&tlb, mm, 0); update_hiwater_rss(mm); unmap_vmas(&tlb, vma, start, end, &nr_accounted, NULL); vm_unacct_memory(nr_accounted); - free_pgtables(tlb, vma, prev? prev->vm_end: FIRST_USER_ADDRESS, - next? next->vm_start: 0); - tlb_finish_mmu(tlb, start, end); + free_pgtables(&tlb, vma, prev ? prev->vm_end : FIRST_USER_ADDRESS, + next ? next->vm_start : 0); + tlb_finish_mmu(&tlb, start, end); } /* @@ -2255,7 +2255,7 @@ EXPORT_SYMBOL(do_brk); /* Release all mmaps. */ void exit_mmap(struct mm_struct *mm) { - struct mmu_gather *tlb; + struct mmu_gather tlb; struct vm_area_struct *vma; unsigned long nr_accounted = 0; unsigned long end; @@ -2280,14 +2280,14 @@ void exit_mmap(struct mm_struct *mm) lru_add_drain(); flush_cache_mm(mm); - tlb = tlb_gather_mmu(mm, 1); + tlb_gather_mmu(&tlb, mm, 1); /* update_hiwater_rss(mm) here? but nobody should be looking */ /* Use -1 here to ensure all VMAs in the mm are unmapped */ end = unmap_vmas(&tlb, vma, 0, -1, &nr_accounted, NULL); vm_unacct_memory(nr_accounted); - free_pgtables(tlb, vma, FIRST_USER_ADDRESS, 0); - tlb_finish_mmu(tlb, 0, end); + free_pgtables(&tlb, vma, FIRST_USER_ADDRESS, 0); + tlb_finish_mmu(&tlb, 0, end); /* * Walk the list again, actually closing and freeing it, -- cgit v1.2.3 From 267239116987d64850ad2037d8e0f3071dc3b5ce Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:00 -0700 Subject: mm, powerpc: move the RCU page-table freeing into generic code In case other architectures require RCU freed page-tables to implement gup_fast() and software filled hashes and similar things, provide the means to do so by moving the logic into generic code. Signed-off-by: Peter Zijlstra Requested-by: David Miller Cc: Benjamin Herrenschmidt Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/Kconfig | 3 ++ arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/pgalloc.h | 21 ++++++-- arch/powerpc/include/asm/tlb.h | 10 ---- arch/powerpc/mm/pgtable.c | 98 -------------------------------------- arch/powerpc/mm/tlb_hash32.c | 3 -- arch/powerpc/mm/tlb_hash64.c | 3 -- arch/powerpc/mm/tlb_nohash.c | 3 -- include/asm-generic/tlb.h | 56 ++++++++++++++++++++-- mm/memory.c | 77 ++++++++++++++++++++++++++++++ 10 files changed, 150 insertions(+), 125 deletions(-) (limited to 'mm/memory.c') diff --git a/arch/Kconfig b/arch/Kconfig index 8d24bacaa61e..26b0e2397a57 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -175,4 +175,7 @@ config HAVE_ARCH_JUMP_LABEL config HAVE_ARCH_MUTEX_CPU_RELAX bool +config HAVE_RCU_TABLE_FREE + bool + source "kernel/gcov/Kconfig" diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index a3128ca0fe11..423145a6f7ba 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -140,6 +140,7 @@ config PPC select IRQ_PER_CPU select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL + select HAVE_RCU_TABLE_FREE if SMP config EARLY_PRINTK bool diff --git a/arch/powerpc/include/asm/pgalloc.h b/arch/powerpc/include/asm/pgalloc.h index df1b4cbb2e70..bf301ac62f35 100644 --- a/arch/powerpc/include/asm/pgalloc.h +++ b/arch/powerpc/include/asm/pgalloc.h @@ -31,14 +31,29 @@ static inline void pte_free(struct mm_struct *mm, pgtable_t ptepage) #endif #ifdef CONFIG_SMP -extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift); -extern void pte_free_finish(struct mmu_gather *tlb); +struct mmu_gather; +extern void tlb_remove_table(struct mmu_gather *, void *); + +static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift) +{ + unsigned long pgf = (unsigned long)table; + BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); + pgf |= shift; + tlb_remove_table(tlb, (void *)pgf); +} + +static inline void __tlb_remove_table(void *_table) +{ + void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE); + unsigned shift = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE; + + pgtable_free(table, shift); +} #else /* CONFIG_SMP */ static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift) { pgtable_free(table, shift); } -static inline void pte_free_finish(struct mmu_gather *tlb) { } #endif /* !CONFIG_SMP */ static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *ptepage, diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h index 8f0ed7adcd12..e2b428b0f7ba 100644 --- a/arch/powerpc/include/asm/tlb.h +++ b/arch/powerpc/include/asm/tlb.h @@ -28,16 +28,6 @@ #define tlb_start_vma(tlb, vma) do { } while (0) #define tlb_end_vma(tlb, vma) do { } while (0) -#define HAVE_ARCH_MMU_GATHER 1 - -struct pte_freelist_batch; - -struct arch_mmu_gather { - struct pte_freelist_batch *batch; -}; - -#define ARCH_MMU_GATHER_INIT (struct arch_mmu_gather){ .batch = NULL, } - extern void tlb_flush(struct mmu_gather *tlb); /* Get the generic bits... */ diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c index 6e72788598f8..af40c8768a78 100644 --- a/arch/powerpc/mm/pgtable.c +++ b/arch/powerpc/mm/pgtable.c @@ -33,104 +33,6 @@ #include "mmu_decl.h" -#ifdef CONFIG_SMP - -/* - * Handle batching of page table freeing on SMP. Page tables are - * queued up and send to be freed later by RCU in order to avoid - * freeing a page table page that is being walked without locks - */ - -static unsigned long pte_freelist_forced_free; - -struct pte_freelist_batch -{ - struct rcu_head rcu; - unsigned int index; - unsigned long tables[0]; -}; - -#define PTE_FREELIST_SIZE \ - ((PAGE_SIZE - sizeof(struct pte_freelist_batch)) \ - / sizeof(unsigned long)) - -static void pte_free_smp_sync(void *arg) -{ - /* Do nothing, just ensure we sync with all CPUs */ -} - -/* This is only called when we are critically out of memory - * (and fail to get a page in pte_free_tlb). - */ -static void pgtable_free_now(void *table, unsigned shift) -{ - pte_freelist_forced_free++; - - smp_call_function(pte_free_smp_sync, NULL, 1); - - pgtable_free(table, shift); -} - -static void pte_free_rcu_callback(struct rcu_head *head) -{ - struct pte_freelist_batch *batch = - container_of(head, struct pte_freelist_batch, rcu); - unsigned int i; - - for (i = 0; i < batch->index; i++) { - void *table = (void *)(batch->tables[i] & ~MAX_PGTABLE_INDEX_SIZE); - unsigned shift = batch->tables[i] & MAX_PGTABLE_INDEX_SIZE; - - pgtable_free(table, shift); - } - - free_page((unsigned long)batch); -} - -static void pte_free_submit(struct pte_freelist_batch *batch) -{ - call_rcu_sched(&batch->rcu, pte_free_rcu_callback); -} - -void pgtable_free_tlb(struct mmu_gather *tlb, void *table, unsigned shift) -{ - struct pte_freelist_batch **batchp = &tlb->arch.batch; - unsigned long pgf; - - if (atomic_read(&tlb->mm->mm_users) < 2) { - pgtable_free(table, shift); - return; - } - - if (*batchp == NULL) { - *batchp = (struct pte_freelist_batch *)__get_free_page(GFP_ATOMIC); - if (*batchp == NULL) { - pgtable_free_now(table, shift); - return; - } - (*batchp)->index = 0; - } - BUG_ON(shift > MAX_PGTABLE_INDEX_SIZE); - pgf = (unsigned long)table | shift; - (*batchp)->tables[(*batchp)->index++] = pgf; - if ((*batchp)->index == PTE_FREELIST_SIZE) { - pte_free_submit(*batchp); - *batchp = NULL; - } -} - -void pte_free_finish(struct mmu_gather *tlb) -{ - struct pte_freelist_batch **batchp = &tlb->arch.batch; - - if (*batchp == NULL) - return; - pte_free_submit(*batchp); - *batchp = NULL; -} - -#endif /* CONFIG_SMP */ - static inline int is_exec_fault(void) { return current->thread.regs && TRAP(current->thread.regs) == 0x400; diff --git a/arch/powerpc/mm/tlb_hash32.c b/arch/powerpc/mm/tlb_hash32.c index d555cdb06bc8..27b863c14941 100644 --- a/arch/powerpc/mm/tlb_hash32.c +++ b/arch/powerpc/mm/tlb_hash32.c @@ -71,9 +71,6 @@ void tlb_flush(struct mmu_gather *tlb) */ _tlbia(); } - - /* Push out batch of freed page tables */ - pte_free_finish(tlb); } /* diff --git a/arch/powerpc/mm/tlb_hash64.c b/arch/powerpc/mm/tlb_hash64.c index 5c94ca34cd79..31f18207970b 100644 --- a/arch/powerpc/mm/tlb_hash64.c +++ b/arch/powerpc/mm/tlb_hash64.c @@ -165,9 +165,6 @@ void tlb_flush(struct mmu_gather *tlb) __flush_tlb_pending(tlbbatch); put_cpu_var(ppc64_tlb_batch); - - /* Push out batch of freed page tables */ - pte_free_finish(tlb); } /** diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c index 8eaf67d32043..0bdad3aecc67 100644 --- a/arch/powerpc/mm/tlb_nohash.c +++ b/arch/powerpc/mm/tlb_nohash.c @@ -299,9 +299,6 @@ EXPORT_SYMBOL(flush_tlb_range); void tlb_flush(struct mmu_gather *tlb) { flush_tlb_mm(tlb->mm); - - /* Push out batch of freed page tables */ - pte_free_finish(tlb); } /* diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 2d3547c84235..74f80f6b6cf1 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -29,6 +29,49 @@ #define tlb_fast_mode(tlb) 1 #endif +#ifdef CONFIG_HAVE_RCU_TABLE_FREE +/* + * Semi RCU freeing of the page directories. + * + * This is needed by some architectures to implement software pagetable walkers. + * + * gup_fast() and other software pagetable walkers do a lockless page-table + * walk and therefore needs some synchronization with the freeing of the page + * directories. The chosen means to accomplish that is by disabling IRQs over + * the walk. + * + * Architectures that use IPIs to flush TLBs will then automagically DTRT, + * since we unlink the page, flush TLBs, free the page. Since the disabling of + * IRQs delays the completion of the TLB flush we can never observe an already + * freed page. + * + * Architectures that do not have this (PPC) need to delay the freeing by some + * other means, this is that means. + * + * What we do is batch the freed directory pages (tables) and RCU free them. + * We use the sched RCU variant, as that guarantees that IRQ/preempt disabling + * holds off grace periods. + * + * However, in order to batch these pages we need to allocate storage, this + * allocation is deep inside the MM code and can thus easily fail on memory + * pressure. To guarantee progress we fall back to single table freeing, see + * the implementation of tlb_remove_table_one(). + * + */ +struct mmu_table_batch { + struct rcu_head rcu; + unsigned int nr; + void *tables[0]; +}; + +#define MAX_TABLE_BATCH \ + ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) + +extern void tlb_table_flush(struct mmu_gather *tlb); +extern void tlb_remove_table(struct mmu_gather *tlb, void *table); + +#endif + /* * If we can't allocate a page to make a big batch of page pointers * to work on, then just handle a few from the on-stack structure. @@ -40,13 +83,13 @@ */ struct mmu_gather { struct mm_struct *mm; +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + struct mmu_table_batch *batch; +#endif unsigned int nr; /* set to ~0U means fast mode */ unsigned int max; /* nr < max */ unsigned int need_flush;/* Really unmapped some ptes? */ unsigned int fullmm; /* non-zero means full mm flush */ -#ifdef HAVE_ARCH_MMU_GATHER - struct arch_mmu_gather arch; -#endif struct page **pages; struct page *local[MMU_GATHER_BUNDLE]; }; @@ -82,8 +125,8 @@ tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) tlb->fullmm = fullmm; -#ifdef HAVE_ARCH_MMU_GATHER - tlb->arch = ARCH_MMU_GATHER_INIT; +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + tlb->batch = NULL; #endif } @@ -94,6 +137,9 @@ tlb_flush_mmu(struct mmu_gather *tlb) return; tlb->need_flush = 0; tlb_flush(tlb); +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + tlb_table_flush(tlb); +#endif if (!tlb_fast_mode(tlb)) { free_pages_and_swap_cache(tlb->pages, tlb->nr); tlb->nr = 0; diff --git a/mm/memory.c b/mm/memory.c index 19b2d44de9f0..a77fd23ee68a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -193,6 +193,83 @@ static void check_sync_rss_stat(struct task_struct *task) #endif +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + +/* + * See the comment near struct mmu_table_batch. + */ + +static void tlb_remove_table_smp_sync(void *arg) +{ + /* Simply deliver the interrupt */ +} + +static void tlb_remove_table_one(void *table) +{ + /* + * This isn't an RCU grace period and hence the page-tables cannot be + * assumed to be actually RCU-freed. + * + * It is however sufficient for software page-table walkers that rely on + * IRQ disabling. See the comment near struct mmu_table_batch. + */ + smp_call_function(tlb_remove_table_smp_sync, NULL, 1); + __tlb_remove_table(table); +} + +static void tlb_remove_table_rcu(struct rcu_head *head) +{ + struct mmu_table_batch *batch; + int i; + + batch = container_of(head, struct mmu_table_batch, rcu); + + for (i = 0; i < batch->nr; i++) + __tlb_remove_table(batch->tables[i]); + + free_page((unsigned long)batch); +} + +void tlb_table_flush(struct mmu_gather *tlb) +{ + struct mmu_table_batch **batch = &tlb->batch; + + if (*batch) { + call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); + *batch = NULL; + } +} + +void tlb_remove_table(struct mmu_gather *tlb, void *table) +{ + struct mmu_table_batch **batch = &tlb->batch; + + tlb->need_flush = 1; + + /* + * When there's less then two users of this mm there cannot be a + * concurrent page-table walk. + */ + if (atomic_read(&tlb->mm->mm_users) < 2) { + __tlb_remove_table(table); + return; + } + + if (*batch == NULL) { + *batch = (struct mmu_table_batch *)__get_free_page(GFP_NOWAIT | __GFP_NOWARN); + if (*batch == NULL) { + tlb_remove_table_one(table); + return; + } + (*batch)->nr = 0; + } + (*batch)->tables[(*batch)->nr++] = table; + if ((*batch)->nr == MAX_TABLE_BATCH) + tlb_table_flush(tlb); +} + +#endif + /* * If a p?d_bad entry is found while walking page tables, report * the error, before resetting entry to p?d_none. Usually (but -- cgit v1.2.3 From e303297e6c3a7b847c4731eb14006ca6b435ecca Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:01 -0700 Subject: mm: extended batches for generic mmu_gather Instead of using a single batch (the small on-stack, or an allocated page), try and extend the batch every time it runs out and only flush once either the extend fails or we're done. Signed-off-by: Peter Zijlstra Requested-by: Nick Piggin Reviewed-by: KAMEZAWA Hiroyuki Acked-by: Hugh Dickins Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/tlb.h | 129 +++++++++++++++++++++++++++++----------------- mm/memory.c | 2 +- 2 files changed, 84 insertions(+), 47 deletions(-) (limited to 'mm/memory.c') diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 74f80f6b6cf1..5a946a08ff9d 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -19,16 +19,6 @@ #include #include -/* - * For UP we don't need to worry about TLB flush - * and page free order so much.. - */ -#ifdef CONFIG_SMP - #define tlb_fast_mode(tlb) ((tlb)->nr == ~0U) -#else - #define tlb_fast_mode(tlb) 1 -#endif - #ifdef CONFIG_HAVE_RCU_TABLE_FREE /* * Semi RCU freeing of the page directories. @@ -78,6 +68,16 @@ extern void tlb_remove_table(struct mmu_gather *tlb, void *table); */ #define MMU_GATHER_BUNDLE 8 +struct mmu_gather_batch { + struct mmu_gather_batch *next; + unsigned int nr; + unsigned int max; + struct page *pages[0]; +}; + +#define MAX_GATHER_BATCH \ + ((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *)) + /* struct mmu_gather is an opaque type used by the mm code for passing around * any data needed by arch specific code for tlb_remove_page. */ @@ -86,22 +86,48 @@ struct mmu_gather { #ifdef CONFIG_HAVE_RCU_TABLE_FREE struct mmu_table_batch *batch; #endif - unsigned int nr; /* set to ~0U means fast mode */ - unsigned int max; /* nr < max */ - unsigned int need_flush;/* Really unmapped some ptes? */ - unsigned int fullmm; /* non-zero means full mm flush */ - struct page **pages; - struct page *local[MMU_GATHER_BUNDLE]; + unsigned int need_flush : 1, /* Did free PTEs */ + fast_mode : 1; /* No batching */ + + unsigned int fullmm; + + struct mmu_gather_batch *active; + struct mmu_gather_batch local; + struct page *__pages[MMU_GATHER_BUNDLE]; }; -static inline void __tlb_alloc_page(struct mmu_gather *tlb) +/* + * For UP we don't need to worry about TLB flush + * and page free order so much.. + */ +#ifdef CONFIG_SMP + #define tlb_fast_mode(tlb) (tlb->fast_mode) +#else + #define tlb_fast_mode(tlb) 1 +#endif + +static inline int tlb_next_batch(struct mmu_gather *tlb) { - unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + struct mmu_gather_batch *batch; - if (addr) { - tlb->pages = (void *)addr; - tlb->max = PAGE_SIZE / sizeof(struct page *); + batch = tlb->active; + if (batch->next) { + tlb->active = batch->next; + return 1; } + + batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + if (!batch) + return 0; + + batch->next = NULL; + batch->nr = 0; + batch->max = MAX_GATHER_BATCH; + + tlb->active->next = batch; + tlb->active = batch; + + return 1; } /* tlb_gather_mmu @@ -114,16 +140,13 @@ tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) { tlb->mm = mm; - tlb->max = ARRAY_SIZE(tlb->local); - tlb->pages = tlb->local; - - if (num_online_cpus() > 1) { - tlb->nr = 0; - __tlb_alloc_page(tlb); - } else /* Use fast mode if only one CPU is online */ - tlb->nr = ~0U; - - tlb->fullmm = fullmm; + tlb->fullmm = fullmm; + tlb->need_flush = 0; + tlb->fast_mode = (num_possible_cpus() == 1); + tlb->local.next = NULL; + tlb->local.nr = 0; + tlb->local.max = ARRAY_SIZE(tlb->__pages); + tlb->active = &tlb->local; #ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb->batch = NULL; @@ -133,6 +156,8 @@ tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) static inline void tlb_flush_mmu(struct mmu_gather *tlb) { + struct mmu_gather_batch *batch; + if (!tlb->need_flush) return; tlb->need_flush = 0; @@ -140,17 +165,15 @@ tlb_flush_mmu(struct mmu_gather *tlb) #ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb_table_flush(tlb); #endif - if (!tlb_fast_mode(tlb)) { - free_pages_and_swap_cache(tlb->pages, tlb->nr); - tlb->nr = 0; - /* - * If we are using the local on-stack array of pages for MMU - * gather, try allocating an off-stack array again as we have - * recently freed pages. - */ - if (tlb->pages == tlb->local) - __tlb_alloc_page(tlb); + + if (tlb_fast_mode(tlb)) + return; + + for (batch = &tlb->local; batch; batch = batch->next) { + free_pages_and_swap_cache(batch->pages, batch->nr); + batch->nr = 0; } + tlb->active = &tlb->local; } /* tlb_finish_mmu @@ -160,13 +183,18 @@ tlb_flush_mmu(struct mmu_gather *tlb) static inline void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) { + struct mmu_gather_batch *batch, *next; + tlb_flush_mmu(tlb); /* keep the page table cache within bounds */ check_pgt_cache(); - if (tlb->pages != tlb->local) - free_pages((unsigned long)tlb->pages, 0); + for (batch = tlb->local.next; batch; batch = next) { + next = batch->next; + free_pages((unsigned long)batch, 0); + } + tlb->local.next = NULL; } /* __tlb_remove_page @@ -177,15 +205,24 @@ tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) */ static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) { + struct mmu_gather_batch *batch; + tlb->need_flush = 1; + if (tlb_fast_mode(tlb)) { free_page_and_swap_cache(page); return 1; /* avoid calling tlb_flush_mmu() */ } - tlb->pages[tlb->nr++] = page; - VM_BUG_ON(tlb->nr > tlb->max); - return tlb->max - tlb->nr; + batch = tlb->active; + batch->pages[batch->nr++] = page; + VM_BUG_ON(batch->nr > batch->max); + if (batch->nr == batch->max) { + if (!tlb_next_batch(tlb)) + return 0; + } + + return batch->max - batch->nr; } /* tlb_remove_page diff --git a/mm/memory.c b/mm/memory.c index a77fd23ee68a..17193d74f302 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -994,8 +994,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, spinlock_t *ptl; int rss[NR_MM_COUNTERS]; - init_rss_vec(rss); again: + init_rss_vec(rss); pte = pte_offset_map_lock(mm, pmd, addr, &ptl); arch_enter_lazy_mmu_mode(); do { -- cgit v1.2.3 From 97a894136f29802da19a15541de3c019e1ca147e Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:04 -0700 Subject: mm: Remove i_mmap_lock lockbreak Hugh says: "The only significant loser, I think, would be page reclaim (when concurrent with truncation): could spin for a long time waiting for the i_mmap_mutex it expects would soon be dropped? " Counter points: - cpu contention makes the spin stop (need_resched()) - zap pages should be freeing pages at a higher rate than reclaim ever can I think the simplification of the truncate code is definitely worth it. Effectively reverts: 2aa15890f3c ("mm: prevent concurrent unmap_mapping_range() on the same inode") and takes out the code that caused its problem. Signed-off-by: Peter Zijlstra Reviewed-by: KAMEZAWA Hiroyuki Cc: Hugh Dickins Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/inode.c | 1 - include/linux/fs.h | 2 - include/linux/mm.h | 2 - include/linux/mm_types.h | 1 - kernel/fork.c | 1 - mm/memory.c | 195 +++++++---------------------------------------- mm/mmap.c | 13 +--- mm/mremap.c | 1 - 8 files changed, 28 insertions(+), 188 deletions(-) (limited to 'mm/memory.c') diff --git a/fs/inode.c b/fs/inode.c index 05f4fa521325..7a7284c71abd 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -331,7 +331,6 @@ void address_space_init_once(struct address_space *mapping) spin_lock_init(&mapping->private_lock); INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap); INIT_LIST_HEAD(&mapping->i_mmap_nonlinear); - mutex_init(&mapping->unmap_mutex); } EXPORT_SYMBOL(address_space_init_once); diff --git a/include/linux/fs.h b/include/linux/fs.h index cdf9495df204..5d2c86bdf5ba 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -635,7 +635,6 @@ struct address_space { struct prio_tree_root i_mmap; /* tree of private and shared mappings */ struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */ spinlock_t i_mmap_lock; /* protect tree, count, list */ - unsigned int truncate_count; /* Cover race condition with truncate */ unsigned long nrpages; /* number of total pages */ pgoff_t writeback_index;/* writeback starts here */ const struct address_space_operations *a_ops; /* methods */ @@ -644,7 +643,6 @@ struct address_space { spinlock_t private_lock; /* for use by the address_space */ struct list_head private_list; /* ditto */ struct address_space *assoc_mapping; /* ditto */ - struct mutex unmap_mutex; /* to protect unmapping */ } __attribute__((aligned(sizeof(long)))); /* * On most architectures that alignment is already the case; but diff --git a/include/linux/mm.h b/include/linux/mm.h index ffcce9bf2b54..2ad0ac8c3f32 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -895,8 +895,6 @@ struct zap_details { struct address_space *check_mapping; /* Check page->mapping if set */ pgoff_t first_index; /* Lowest page->index to unmap */ pgoff_t last_index; /* Highest page->index to unmap */ - spinlock_t *i_mmap_lock; /* For unmap_mapping_range: */ - unsigned long truncate_count; /* Compare vm_truncate_count */ }; struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 02aa5619709b..201998e5b530 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -175,7 +175,6 @@ struct vm_area_struct { units, *not* PAGE_CACHE_SIZE */ struct file * vm_file; /* File we map to (can be NULL). */ void * vm_private_data; /* was vm_pte (shared mem) */ - unsigned long vm_truncate_count;/* truncate_count or restart_addr */ #ifndef CONFIG_MMU struct vm_region *vm_region; /* NOMMU mapping region */ diff --git a/kernel/fork.c b/kernel/fork.c index 2b44d82b8237..4eef925477fc 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -386,7 +386,6 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) spin_lock(&mapping->i_mmap_lock); if (tmp->vm_flags & VM_SHARED) mapping->i_mmap_writable++; - tmp->vm_truncate_count = mpnt->vm_truncate_count; flush_dcache_mmap_lock(mapping); /* insert tmp into the share list, just after mpnt */ vma_prio_tree_add(tmp, mpnt); diff --git a/mm/memory.c b/mm/memory.c index 17193d74f302..18655878b9f8 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -986,13 +986,13 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, static unsigned long zap_pte_range(struct mmu_gather *tlb, struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, - long *zap_work, struct zap_details *details) + struct zap_details *details) { struct mm_struct *mm = tlb->mm; int force_flush = 0; - pte_t *pte; - spinlock_t *ptl; int rss[NR_MM_COUNTERS]; + spinlock_t *ptl; + pte_t *pte; again: init_rss_vec(rss); @@ -1001,12 +1001,9 @@ again: do { pte_t ptent = *pte; if (pte_none(ptent)) { - (*zap_work)--; continue; } - (*zap_work) -= PAGE_SIZE; - if (pte_present(ptent)) { struct page *page; @@ -1075,7 +1072,7 @@ again: print_bad_pte(vma, addr, ptent, NULL); } pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); - } while (pte++, addr += PAGE_SIZE, (addr != end && *zap_work > 0)); + } while (pte++, addr += PAGE_SIZE, addr != end); add_mm_rss_vec(mm, rss); arch_leave_lazy_mmu_mode(); @@ -1099,7 +1096,7 @@ again: static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, struct vm_area_struct *vma, pud_t *pud, unsigned long addr, unsigned long end, - long *zap_work, struct zap_details *details) + struct zap_details *details) { pmd_t *pmd; unsigned long next; @@ -1111,19 +1108,15 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, if (next-addr != HPAGE_PMD_SIZE) { VM_BUG_ON(!rwsem_is_locked(&tlb->mm->mmap_sem)); split_huge_page_pmd(vma->vm_mm, pmd); - } else if (zap_huge_pmd(tlb, vma, pmd)) { - (*zap_work)--; + } else if (zap_huge_pmd(tlb, vma, pmd)) continue; - } /* fall through */ } - if (pmd_none_or_clear_bad(pmd)) { - (*zap_work)--; + if (pmd_none_or_clear_bad(pmd)) continue; - } - next = zap_pte_range(tlb, vma, pmd, addr, next, - zap_work, details); - } while (pmd++, addr = next, (addr != end && *zap_work > 0)); + next = zap_pte_range(tlb, vma, pmd, addr, next, details); + cond_resched(); + } while (pmd++, addr = next, addr != end); return addr; } @@ -1131,7 +1124,7 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb, static inline unsigned long zap_pud_range(struct mmu_gather *tlb, struct vm_area_struct *vma, pgd_t *pgd, unsigned long addr, unsigned long end, - long *zap_work, struct zap_details *details) + struct zap_details *details) { pud_t *pud; unsigned long next; @@ -1139,13 +1132,10 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb, pud = pud_offset(pgd, addr); do { next = pud_addr_end(addr, end); - if (pud_none_or_clear_bad(pud)) { - (*zap_work)--; + if (pud_none_or_clear_bad(pud)) continue; - } - next = zap_pmd_range(tlb, vma, pud, addr, next, - zap_work, details); - } while (pud++, addr = next, (addr != end && *zap_work > 0)); + next = zap_pmd_range(tlb, vma, pud, addr, next, details); + } while (pud++, addr = next, addr != end); return addr; } @@ -1153,7 +1143,7 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb, static unsigned long unmap_page_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long addr, unsigned long end, - long *zap_work, struct zap_details *details) + struct zap_details *details) { pgd_t *pgd; unsigned long next; @@ -1167,13 +1157,10 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb, pgd = pgd_offset(vma->vm_mm, addr); do { next = pgd_addr_end(addr, end); - if (pgd_none_or_clear_bad(pgd)) { - (*zap_work)--; + if (pgd_none_or_clear_bad(pgd)) continue; - } - next = zap_pud_range(tlb, vma, pgd, addr, next, - zap_work, details); - } while (pgd++, addr = next, (addr != end && *zap_work > 0)); + next = zap_pud_range(tlb, vma, pgd, addr, next, details); + } while (pgd++, addr = next, addr != end); tlb_end_vma(tlb, vma); mem_cgroup_uncharge_end(); @@ -1218,9 +1205,7 @@ unsigned long unmap_vmas(struct mmu_gather *tlb, unsigned long end_addr, unsigned long *nr_accounted, struct zap_details *details) { - long zap_work = ZAP_BLOCK_SIZE; unsigned long start = start_addr; - spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL; struct mm_struct *mm = vma->vm_mm; mmu_notifier_invalidate_range_start(mm, start_addr, end_addr); @@ -1253,33 +1238,15 @@ unsigned long unmap_vmas(struct mmu_gather *tlb, * Since no pte has actually been setup, it is * safe to do nothing in this case. */ - if (vma->vm_file) { + if (vma->vm_file) unmap_hugepage_range(vma, start, end, NULL); - zap_work -= (end - start) / - pages_per_huge_page(hstate_vma(vma)); - } start = end; } else - start = unmap_page_range(tlb, vma, - start, end, &zap_work, details); - - if (zap_work > 0) { - BUG_ON(start != end); - break; - } - - if (need_resched() || - (i_mmap_lock && spin_needbreak(i_mmap_lock))) { - if (i_mmap_lock) - goto out; - cond_resched(); - } - - zap_work = ZAP_BLOCK_SIZE; + start = unmap_page_range(tlb, vma, start, end, details); } } -out: + mmu_notifier_invalidate_range_end(mm, start_addr, end_addr); return start; /* which is now the end (or restart) address */ } @@ -2612,96 +2579,11 @@ unwritable_page: return ret; } -/* - * Helper functions for unmap_mapping_range(). - * - * __ Notes on dropping i_mmap_lock to reduce latency while unmapping __ - * - * We have to restart searching the prio_tree whenever we drop the lock, - * since the iterator is only valid while the lock is held, and anyway - * a later vma might be split and reinserted earlier while lock dropped. - * - * The list of nonlinear vmas could be handled more efficiently, using - * a placeholder, but handle it in the same way until a need is shown. - * It is important to search the prio_tree before nonlinear list: a vma - * may become nonlinear and be shifted from prio_tree to nonlinear list - * while the lock is dropped; but never shifted from list to prio_tree. - * - * In order to make forward progress despite restarting the search, - * vm_truncate_count is used to mark a vma as now dealt with, so we can - * quickly skip it next time around. Since the prio_tree search only - * shows us those vmas affected by unmapping the range in question, we - * can't efficiently keep all vmas in step with mapping->truncate_count: - * so instead reset them all whenever it wraps back to 0 (then go to 1). - * mapping->truncate_count and vma->vm_truncate_count are protected by - * i_mmap_lock. - * - * In order to make forward progress despite repeatedly restarting some - * large vma, note the restart_addr from unmap_vmas when it breaks out: - * and restart from that address when we reach that vma again. It might - * have been split or merged, shrunk or extended, but never shifted: so - * restart_addr remains valid so long as it remains in the vma's range. - * unmap_mapping_range forces truncate_count to leap over page-aligned - * values so we can save vma's restart_addr in its truncate_count field. - */ -#define is_restart_addr(truncate_count) (!((truncate_count) & ~PAGE_MASK)) - -static void reset_vma_truncate_counts(struct address_space *mapping) -{ - struct vm_area_struct *vma; - struct prio_tree_iter iter; - - vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, 0, ULONG_MAX) - vma->vm_truncate_count = 0; - list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) - vma->vm_truncate_count = 0; -} - -static int unmap_mapping_range_vma(struct vm_area_struct *vma, +static void unmap_mapping_range_vma(struct vm_area_struct *vma, unsigned long start_addr, unsigned long end_addr, struct zap_details *details) { - unsigned long restart_addr; - int need_break; - - /* - * files that support invalidating or truncating portions of the - * file from under mmaped areas must have their ->fault function - * return a locked page (and set VM_FAULT_LOCKED in the return). - * This provides synchronisation against concurrent unmapping here. - */ - -again: - restart_addr = vma->vm_truncate_count; - if (is_restart_addr(restart_addr) && start_addr < restart_addr) { - start_addr = restart_addr; - if (start_addr >= end_addr) { - /* Top of vma has been split off since last time */ - vma->vm_truncate_count = details->truncate_count; - return 0; - } - } - - restart_addr = zap_page_range(vma, start_addr, - end_addr - start_addr, details); - need_break = need_resched() || spin_needbreak(details->i_mmap_lock); - - if (restart_addr >= end_addr) { - /* We have now completed this vma: mark it so */ - vma->vm_truncate_count = details->truncate_count; - if (!need_break) - return 0; - } else { - /* Note restart_addr in vma's truncate_count field */ - vma->vm_truncate_count = restart_addr; - if (!need_break) - goto again; - } - - spin_unlock(details->i_mmap_lock); - cond_resched(); - spin_lock(details->i_mmap_lock); - return -EINTR; + zap_page_range(vma, start_addr, end_addr - start_addr, details); } static inline void unmap_mapping_range_tree(struct prio_tree_root *root, @@ -2711,12 +2593,8 @@ static inline void unmap_mapping_range_tree(struct prio_tree_root *root, struct prio_tree_iter iter; pgoff_t vba, vea, zba, zea; -restart: vma_prio_tree_foreach(vma, &iter, root, details->first_index, details->last_index) { - /* Skip quickly over those we have already dealt with */ - if (vma->vm_truncate_count == details->truncate_count) - continue; vba = vma->vm_pgoff; vea = vba + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) - 1; @@ -2728,11 +2606,10 @@ restart: if (zea > vea) zea = vea; - if (unmap_mapping_range_vma(vma, + unmap_mapping_range_vma(vma, ((zba - vba) << PAGE_SHIFT) + vma->vm_start, ((zea - vba + 1) << PAGE_SHIFT) + vma->vm_start, - details) < 0) - goto restart; + details); } } @@ -2747,15 +2624,9 @@ static inline void unmap_mapping_range_list(struct list_head *head, * across *all* the pages in each nonlinear VMA, not just the pages * whose virtual address lies outside the file truncation point. */ -restart: list_for_each_entry(vma, head, shared.vm_set.list) { - /* Skip quickly over those we have already dealt with */ - if (vma->vm_truncate_count == details->truncate_count) - continue; details->nonlinear_vma = vma; - if (unmap_mapping_range_vma(vma, vma->vm_start, - vma->vm_end, details) < 0) - goto restart; + unmap_mapping_range_vma(vma, vma->vm_start, vma->vm_end, details); } } @@ -2794,26 +2665,14 @@ void unmap_mapping_range(struct address_space *mapping, details.last_index = hba + hlen - 1; if (details.last_index < details.first_index) details.last_index = ULONG_MAX; - details.i_mmap_lock = &mapping->i_mmap_lock; - mutex_lock(&mapping->unmap_mutex); - spin_lock(&mapping->i_mmap_lock); - - /* Protect against endless unmapping loops */ - mapping->truncate_count++; - if (unlikely(is_restart_addr(mapping->truncate_count))) { - if (mapping->truncate_count == 0) - reset_vma_truncate_counts(mapping); - mapping->truncate_count++; - } - details.truncate_count = mapping->truncate_count; + spin_lock(&mapping->i_mmap_lock); if (unlikely(!prio_tree_empty(&mapping->i_mmap))) unmap_mapping_range_tree(&mapping->i_mmap, &details); if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details); spin_unlock(&mapping->i_mmap_lock); - mutex_unlock(&mapping->unmap_mutex); } EXPORT_SYMBOL(unmap_mapping_range); diff --git a/mm/mmap.c b/mm/mmap.c index 40d49986e714..50cb04bb56bf 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -445,10 +445,8 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma, if (vma->vm_file) mapping = vma->vm_file->f_mapping; - if (mapping) { + if (mapping) spin_lock(&mapping->i_mmap_lock); - vma->vm_truncate_count = mapping->truncate_count; - } __vma_link(mm, vma, prev, rb_link, rb_parent); __vma_link_file(vma); @@ -558,16 +556,7 @@ again: remove_next = 1 + (end > next->vm_end); if (!(vma->vm_flags & VM_NONLINEAR)) root = &mapping->i_mmap; spin_lock(&mapping->i_mmap_lock); - if (importer && - vma->vm_truncate_count != next->vm_truncate_count) { - /* - * unmap_mapping_range might be in progress: - * ensure that the expanding vma is rescanned. - */ - importer->vm_truncate_count = 0; - } if (insert) { - insert->vm_truncate_count = vma->vm_truncate_count; /* * Put into prio_tree now, so instantiated pages * are visible to arm/parisc __flush_dcache_page diff --git a/mm/mremap.c b/mm/mremap.c index a7c1f9f9b941..909e1e1e99b1 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -94,7 +94,6 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, */ mapping = vma->vm_file->f_mapping; spin_lock(&mapping->i_mmap_lock); - new_vma->vm_truncate_count = 0; } /* -- cgit v1.2.3 From 3d48ae45e72390ddf8cc5256ac32ed6f7a19cbea Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:06 -0700 Subject: mm: Convert i_mmap_lock to a mutex Straightforward conversion of i_mmap_lock to a mutex. Signed-off-by: Peter Zijlstra Acked-by: Hugh Dickins Cc: Benjamin Herrenschmidt Cc: David Miller Cc: Martin Schwidefsky Cc: Russell King Cc: Paul Mundt Cc: Jeff Dike Cc: Richard Weinberger Cc: Tony Luck Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: KOSAKI Motohiro Cc: Nick Piggin Cc: Namhyung Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/lockstat.txt | 2 +- Documentation/vm/locking | 2 +- arch/x86/mm/hugetlbpage.c | 4 ++-- fs/hugetlbfs/inode.c | 4 ++-- fs/inode.c | 2 +- include/linux/fs.h | 2 +- include/linux/mmu_notifier.h | 2 +- kernel/fork.c | 4 ++-- mm/filemap.c | 10 +++++----- mm/filemap_xip.c | 4 ++-- mm/fremap.c | 4 ++-- mm/hugetlb.c | 14 +++++++------- mm/memory-failure.c | 4 ++-- mm/memory.c | 4 ++-- mm/mmap.c | 22 +++++++++++----------- mm/mremap.c | 4 ++-- mm/rmap.c | 28 ++++++++++++++-------------- 17 files changed, 58 insertions(+), 58 deletions(-) (limited to 'mm/memory.c') diff --git a/Documentation/lockstat.txt b/Documentation/lockstat.txt index 65f4c795015d..9c0a80d17a23 100644 --- a/Documentation/lockstat.txt +++ b/Documentation/lockstat.txt @@ -136,7 +136,7 @@ View the top contending locks: dcache_lock: 1037 1161 0.38 45.32 774.51 6611 243371 0.15 306.48 77387.24 &inode->i_mutex: 161 286 18446744073709 62882.54 1244614.55 3653 20598 18446744073709 62318.60 1693822.74 &zone->lru_lock: 94 94 0.53 7.33 92.10 4366 32690 0.29 59.81 16350.06 - &inode->i_data.i_mmap_lock: 79 79 0.40 3.77 53.03 11779 87755 0.28 116.93 29898.44 + &inode->i_data.i_mmap_mutex: 79 79 0.40 3.77 53.03 11779 87755 0.28 116.93 29898.44 &q->__queue_lock: 48 50 0.52 31.62 86.31 774 13131 0.17 113.08 12277.52 &rq->rq_lock_key: 43 47 0.74 68.50 170.63 3706 33929 0.22 107.99 17460.62 &rq->rq_lock_key#2: 39 46 0.75 6.68 49.03 2979 32292 0.17 125.17 17137.63 diff --git a/Documentation/vm/locking b/Documentation/vm/locking index 25fadb448760..f61228bd6395 100644 --- a/Documentation/vm/locking +++ b/Documentation/vm/locking @@ -66,7 +66,7 @@ in some cases it is not really needed. Eg, vm_start is modified by expand_stack(), it is hard to come up with a destructive scenario without having the vmlist protection in this case. -The page_table_lock nests with the inode i_mmap_lock and the kmem cache +The page_table_lock nests with the inode i_mmap_mutex and the kmem cache c_spinlock spinlocks. This is okay, since the kmem code asks for pages after dropping c_spinlock. The page_table_lock also nests with pagecache_lock and pagemap_lru_lock spinlocks, and no code asks for memory with these locks diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index d4203988504a..f581a18c0d4d 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -72,7 +72,7 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) if (!vma_shareable(vma, addr)) return; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) { if (svma == vma) continue; @@ -97,7 +97,7 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) put_page(virt_to_page(spte)); spin_unlock(&mm->page_table_lock); out: - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); } /* diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index b9eeb1cd03ff..e7a035781b7d 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -412,10 +412,10 @@ static int hugetlb_vmtruncate(struct inode *inode, loff_t offset) pgoff = offset >> PAGE_SHIFT; i_size_write(inode, offset); - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); if (!prio_tree_empty(&mapping->i_mmap)) hugetlb_vmtruncate_list(&mapping->i_mmap, pgoff); - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); truncate_hugepages(inode, offset); return 0; } diff --git a/fs/inode.c b/fs/inode.c index 7a7284c71abd..88aa3bcc7681 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -326,7 +326,7 @@ void address_space_init_once(struct address_space *mapping) memset(mapping, 0, sizeof(*mapping)); INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC); spin_lock_init(&mapping->tree_lock); - spin_lock_init(&mapping->i_mmap_lock); + mutex_init(&mapping->i_mmap_mutex); INIT_LIST_HEAD(&mapping->private_list); spin_lock_init(&mapping->private_lock); INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap); diff --git a/include/linux/fs.h b/include/linux/fs.h index 5d2c86bdf5ba..5bb9e826019b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -634,7 +634,7 @@ struct address_space { unsigned int i_mmap_writable;/* count VM_SHARED mappings */ struct prio_tree_root i_mmap; /* tree of private and shared mappings */ struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */ - spinlock_t i_mmap_lock; /* protect tree, count, list */ + struct mutex i_mmap_mutex; /* protect tree, count, list */ unsigned long nrpages; /* number of total pages */ pgoff_t writeback_index;/* writeback starts here */ const struct address_space_operations *a_ops; /* methods */ diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index cc2e7dfea9d7..a877dfc243eb 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -150,7 +150,7 @@ struct mmu_notifier_ops { * Therefore notifier chains can only be traversed when either * * 1. mmap_sem is held. - * 2. One of the reverse map locks is held (i_mmap_lock or anon_vma->lock). + * 2. One of the reverse map locks is held (i_mmap_mutex or anon_vma->lock). * 3. No other concurrent thread can access the list (release) */ struct mmu_notifier { diff --git a/kernel/fork.c b/kernel/fork.c index 4eef925477fc..927692734bcf 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -383,14 +383,14 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) get_file(file); if (tmp->vm_flags & VM_DENYWRITE) atomic_dec(&inode->i_writecount); - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); if (tmp->vm_flags & VM_SHARED) mapping->i_mmap_writable++; flush_dcache_mmap_lock(mapping); /* insert tmp into the share list, just after mpnt */ vma_prio_tree_add(tmp, mpnt); flush_dcache_mmap_unlock(mapping); - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); } /* diff --git a/mm/filemap.c b/mm/filemap.c index 8144f87dcbb4..88354ae0b1fd 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -58,16 +58,16 @@ /* * Lock ordering: * - * ->i_mmap_lock (truncate_pagecache) + * ->i_mmap_mutex (truncate_pagecache) * ->private_lock (__free_pte->__set_page_dirty_buffers) * ->swap_lock (exclusive_swap_page, others) * ->mapping->tree_lock * * ->i_mutex - * ->i_mmap_lock (truncate->unmap_mapping_range) + * ->i_mmap_mutex (truncate->unmap_mapping_range) * * ->mmap_sem - * ->i_mmap_lock + * ->i_mmap_mutex * ->page_table_lock or pte_lock (various, mainly in memory.c) * ->mapping->tree_lock (arch-dependent flush_dcache_mmap_lock) * @@ -84,7 +84,7 @@ * sb_lock (fs/fs-writeback.c) * ->mapping->tree_lock (__sync_single_inode) * - * ->i_mmap_lock + * ->i_mmap_mutex * ->anon_vma.lock (vma_adjust) * * ->anon_vma.lock @@ -106,7 +106,7 @@ * * (code doesn't rely on that order, so you could switch it around) * ->tasklist_lock (memory_failure, collect_procs_ao) - * ->i_mmap_lock + * ->i_mmap_mutex */ /* diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 83364df74a33..93356cd12828 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -183,7 +183,7 @@ __xip_unmap (struct address_space * mapping, return; retry: - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { mm = vma->vm_mm; address = vma->vm_start + @@ -201,7 +201,7 @@ retry: page_cache_release(page); } } - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); if (locked) { mutex_unlock(&xip_sparse_mutex); diff --git a/mm/fremap.c b/mm/fremap.c index ec520c7b28df..7f4123056e06 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -211,13 +211,13 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, } goto out; } - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); flush_dcache_mmap_lock(mapping); vma->vm_flags |= VM_NONLINEAR; vma_prio_tree_remove(vma, &mapping->i_mmap); vma_nonlinear_insert(vma, &mapping->i_mmap_nonlinear); flush_dcache_mmap_unlock(mapping); - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); } if (vma->vm_flags & VM_LOCKED) { diff --git a/mm/hugetlb.c b/mm/hugetlb.c index bbb4a5bbb958..5fd68b95c671 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2205,7 +2205,7 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long sz = huge_page_size(h); /* - * A page gathering list, protected by per file i_mmap_lock. The + * A page gathering list, protected by per file i_mmap_mutex. The * lock is used to avoid list corruption from multiple unmapping * of the same page since we are using page->lru. */ @@ -2274,9 +2274,9 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, unsigned long end, struct page *ref_page) { - spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); + mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex); __unmap_hugepage_range(vma, start, end, ref_page); - spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); + mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex); } /* @@ -2308,7 +2308,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, * this mapping should be shared between all the VMAs, * __unmap_hugepage_range() is called as the lock is already held */ - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) { /* Do not unmap the current VMA */ if (iter_vma == vma) @@ -2326,7 +2326,7 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma, address, address + huge_page_size(h), page); } - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); return 1; } @@ -2810,7 +2810,7 @@ void hugetlb_change_protection(struct vm_area_struct *vma, BUG_ON(address >= end); flush_cache_range(vma, address, end); - spin_lock(&vma->vm_file->f_mapping->i_mmap_lock); + mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex); spin_lock(&mm->page_table_lock); for (; address < end; address += huge_page_size(h)) { ptep = huge_pte_offset(mm, address); @@ -2825,7 +2825,7 @@ void hugetlb_change_protection(struct vm_area_struct *vma, } } spin_unlock(&mm->page_table_lock); - spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock); + mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex); flush_tlb_range(vma, start, end); } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 2b9a5eef39e0..12178ec32ab5 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -429,7 +429,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, */ read_lock(&tasklist_lock); - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); for_each_process(tsk) { pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); @@ -449,7 +449,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, add_to_kill(tsk, page, vma, to_kill, tkc); } } - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); read_unlock(&tasklist_lock); } diff --git a/mm/memory.c b/mm/memory.c index 18655878b9f8..7bbe4d3df756 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2667,12 +2667,12 @@ void unmap_mapping_range(struct address_space *mapping, details.last_index = ULONG_MAX; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); if (unlikely(!prio_tree_empty(&mapping->i_mmap))) unmap_mapping_range_tree(&mapping->i_mmap, &details); if (unlikely(!list_empty(&mapping->i_mmap_nonlinear))) unmap_mapping_range_list(&mapping->i_mmap_nonlinear, &details); - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); } EXPORT_SYMBOL(unmap_mapping_range); diff --git a/mm/mmap.c b/mm/mmap.c index 50cb04bb56bf..26efbfca0b20 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -194,7 +194,7 @@ error: } /* - * Requires inode->i_mapping->i_mmap_lock + * Requires inode->i_mapping->i_mmap_mutex */ static void __remove_shared_vm_struct(struct vm_area_struct *vma, struct file *file, struct address_space *mapping) @@ -222,9 +222,9 @@ void unlink_file_vma(struct vm_area_struct *vma) if (file) { struct address_space *mapping = file->f_mapping; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); __remove_shared_vm_struct(vma, file, mapping); - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); } } @@ -446,13 +446,13 @@ static void vma_link(struct mm_struct *mm, struct vm_area_struct *vma, mapping = vma->vm_file->f_mapping; if (mapping) - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); __vma_link(mm, vma, prev, rb_link, rb_parent); __vma_link_file(vma); if (mapping) - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); mm->map_count++; validate_mm(mm); @@ -555,7 +555,7 @@ again: remove_next = 1 + (end > next->vm_end); mapping = file->f_mapping; if (!(vma->vm_flags & VM_NONLINEAR)) root = &mapping->i_mmap; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); if (insert) { /* * Put into prio_tree now, so instantiated pages @@ -622,7 +622,7 @@ again: remove_next = 1 + (end > next->vm_end); if (anon_vma) anon_vma_unlock(anon_vma); if (mapping) - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); if (remove_next) { if (file) { @@ -2290,7 +2290,7 @@ void exit_mmap(struct mm_struct *mm) /* Insert vm structure into process list sorted by address * and into the inode's i_mmap tree. If vm_file is non-NULL - * then i_mmap_lock is taken here. + * then i_mmap_mutex is taken here. */ int insert_vm_struct(struct mm_struct * mm, struct vm_area_struct * vma) { @@ -2532,7 +2532,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) */ if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); - spin_lock_nest_lock(&mapping->i_mmap_lock, &mm->mmap_sem); + mutex_lock_nest_lock(&mapping->i_mmap_mutex, &mm->mmap_sem); } } @@ -2559,7 +2559,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) * vma in this mm is backed by the same anon_vma or address_space. * * We can take all the locks in random order because the VM code - * taking i_mmap_lock or anon_vma->lock outside the mmap_sem never + * taking i_mmap_mutex or anon_vma->lock outside the mmap_sem never * takes more than one of them in a row. Secondly we're protected * against a concurrent mm_take_all_locks() by the mm_all_locks_mutex. * @@ -2631,7 +2631,7 @@ static void vm_unlock_mapping(struct address_space *mapping) * AS_MM_ALL_LOCKS can't change to 0 from under us * because we hold the mm_all_locks_mutex. */ - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); if (!test_and_clear_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); diff --git a/mm/mremap.c b/mm/mremap.c index 909e1e1e99b1..506fa44403df 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -93,7 +93,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, * and we propagate stale pages into the dst afterward. */ mapping = vma->vm_file->f_mapping; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); } /* @@ -122,7 +122,7 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, pte_unmap(new_pte - 1); pte_unmap_unlock(old_pte - 1, old_ptl); if (mapping) - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); mmu_notifier_invalidate_range_end(vma->vm_mm, old_start, old_end); } diff --git a/mm/rmap.c b/mm/rmap.c index 522e4a93cadd..f0ef7ea5423a 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -24,7 +24,7 @@ * inode->i_alloc_sem (vmtruncate_range) * mm->mmap_sem * page->flags PG_locked (lock_page) - * mapping->i_mmap_lock + * mapping->i_mmap_mutex * anon_vma->lock * mm->page_table_lock or pte_lock * zone->lru_lock (in mark_page_accessed, isolate_lru_page) @@ -646,14 +646,14 @@ static int page_referenced_file(struct page *page, * The page lock not only makes sure that page->mapping cannot * suddenly be NULLified by truncation, it makes sure that the * structure at mapping cannot be freed and reused yet, - * so we can safely take mapping->i_mmap_lock. + * so we can safely take mapping->i_mmap_mutex. */ BUG_ON(!PageLocked(page)); - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); /* - * i_mmap_lock does not stabilize mapcount at all, but mapcount + * i_mmap_mutex does not stabilize mapcount at all, but mapcount * is more likely to be accurate if we note it after spinning. */ mapcount = page_mapcount(page); @@ -675,7 +675,7 @@ static int page_referenced_file(struct page *page, break; } - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); return referenced; } @@ -762,7 +762,7 @@ static int page_mkclean_file(struct address_space *mapping, struct page *page) BUG_ON(PageAnon(page)); - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { if (vma->vm_flags & VM_SHARED) { unsigned long address = vma_address(page, vma); @@ -771,7 +771,7 @@ static int page_mkclean_file(struct address_space *mapping, struct page *page) ret += page_mkclean_one(page, vma, address); } } - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); return ret; } @@ -1119,7 +1119,7 @@ out_mlock: /* * We need mmap_sem locking, Otherwise VM_LOCKED check makes * unstable result and race. Plus, We can't wait here because - * we now hold anon_vma->lock or mapping->i_mmap_lock. + * we now hold anon_vma->lock or mapping->i_mmap_mutex. * if trylock failed, the page remain in evictable lru and later * vmscan could retry to move the page to unevictable lru if the * page is actually mlocked. @@ -1345,7 +1345,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) unsigned long max_nl_size = 0; unsigned int mapcount; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); if (address == -EFAULT) @@ -1391,7 +1391,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) mapcount = page_mapcount(page); if (!mapcount) goto out; - cond_resched_lock(&mapping->i_mmap_lock); + cond_resched(); max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK; if (max_nl_cursor == 0) @@ -1413,7 +1413,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) } vma->vm_private_data = (void *) max_nl_cursor; } - cond_resched_lock(&mapping->i_mmap_lock); + cond_resched(); max_nl_cursor += CLUSTER_SIZE; } while (max_nl_cursor <= max_nl_size); @@ -1425,7 +1425,7 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags) list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.vm_set.list) vma->vm_private_data = NULL; out: - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); return ret; } @@ -1544,7 +1544,7 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *, if (!mapping) return ret; - spin_lock(&mapping->i_mmap_lock); + mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) { unsigned long address = vma_address(page, vma); if (address == -EFAULT) @@ -1558,7 +1558,7 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *, * never contain migration ptes. Decide what to do about this * limitation to linear when we need rmap_walk() on nonlinear. */ - spin_unlock(&mapping->i_mmap_lock); + mutex_unlock(&mapping->i_mmap_mutex); return ret; } -- cgit v1.2.3 From 9547d01bfb9c351dc19067f8a4cea9d3955f4125 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 24 May 2011 17:12:14 -0700 Subject: mm: uninline large generic tlb.h functions Some of these functions have grown beyond inline sanity, move them out-of-line. Signed-off-by: Peter Zijlstra Requested-by: Andrew Morton Requested-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/tlb.h | 135 +++++----------------------------------------- mm/memory.c | 124 +++++++++++++++++++++++++++++++++++++++++- 2 files changed, 135 insertions(+), 124 deletions(-) (limited to 'mm/memory.c') diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 5a946a08ff9d..e58fa777fa09 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -96,134 +96,25 @@ struct mmu_gather { struct page *__pages[MMU_GATHER_BUNDLE]; }; -/* - * For UP we don't need to worry about TLB flush - * and page free order so much.. - */ -#ifdef CONFIG_SMP - #define tlb_fast_mode(tlb) (tlb->fast_mode) -#else - #define tlb_fast_mode(tlb) 1 -#endif +#define HAVE_GENERIC_MMU_GATHER -static inline int tlb_next_batch(struct mmu_gather *tlb) +static inline int tlb_fast_mode(struct mmu_gather *tlb) { - struct mmu_gather_batch *batch; - - batch = tlb->active; - if (batch->next) { - tlb->active = batch->next; - return 1; - } - - batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); - if (!batch) - return 0; - - batch->next = NULL; - batch->nr = 0; - batch->max = MAX_GATHER_BATCH; - - tlb->active->next = batch; - tlb->active = batch; - +#ifdef CONFIG_SMP + return tlb->fast_mode; +#else + /* + * For UP we don't need to worry about TLB flush + * and page free order so much.. + */ return 1; -} - -/* tlb_gather_mmu - * Called to initialize an (on-stack) mmu_gather structure for page-table - * tear-down from @mm. The @fullmm argument is used when @mm is without - * users and we're going to destroy the full address space (exit/execve). - */ -static inline void -tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) -{ - tlb->mm = mm; - - tlb->fullmm = fullmm; - tlb->need_flush = 0; - tlb->fast_mode = (num_possible_cpus() == 1); - tlb->local.next = NULL; - tlb->local.nr = 0; - tlb->local.max = ARRAY_SIZE(tlb->__pages); - tlb->active = &tlb->local; - -#ifdef CONFIG_HAVE_RCU_TABLE_FREE - tlb->batch = NULL; #endif } -static inline void -tlb_flush_mmu(struct mmu_gather *tlb) -{ - struct mmu_gather_batch *batch; - - if (!tlb->need_flush) - return; - tlb->need_flush = 0; - tlb_flush(tlb); -#ifdef CONFIG_HAVE_RCU_TABLE_FREE - tlb_table_flush(tlb); -#endif - - if (tlb_fast_mode(tlb)) - return; - - for (batch = &tlb->local; batch; batch = batch->next) { - free_pages_and_swap_cache(batch->pages, batch->nr); - batch->nr = 0; - } - tlb->active = &tlb->local; -} - -/* tlb_finish_mmu - * Called at the end of the shootdown operation to free up any resources - * that were required. - */ -static inline void -tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) -{ - struct mmu_gather_batch *batch, *next; - - tlb_flush_mmu(tlb); - - /* keep the page table cache within bounds */ - check_pgt_cache(); - - for (batch = tlb->local.next; batch; batch = next) { - next = batch->next; - free_pages((unsigned long)batch, 0); - } - tlb->local.next = NULL; -} - -/* __tlb_remove_page - * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while - * handling the additional races in SMP caused by other CPUs caching valid - * mappings in their TLBs. Returns the number of free page slots left. - * When out of page slots we must call tlb_flush_mmu(). - */ -static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) -{ - struct mmu_gather_batch *batch; - - tlb->need_flush = 1; - - if (tlb_fast_mode(tlb)) { - free_page_and_swap_cache(page); - return 1; /* avoid calling tlb_flush_mmu() */ - } - - batch = tlb->active; - batch->pages[batch->nr++] = page; - VM_BUG_ON(batch->nr > batch->max); - if (batch->nr == batch->max) { - if (!tlb_next_batch(tlb)) - return 0; - } - - return batch->max - batch->nr; -} +void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm); +void tlb_flush_mmu(struct mmu_gather *tlb); +void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end); +int __tlb_remove_page(struct mmu_gather *tlb, struct page *page); /* tlb_remove_page * Similar to __tlb_remove_page but will call tlb_flush_mmu() itself when diff --git a/mm/memory.c b/mm/memory.c index 7bbe4d3df756..b73f677f0bb1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -182,7 +182,7 @@ void sync_mm_rss(struct task_struct *task, struct mm_struct *mm) { __sync_task_rss_stat(task, mm); } -#else +#else /* SPLIT_RSS_COUNTING */ #define inc_mm_counter_fast(mm, member) inc_mm_counter(mm, member) #define dec_mm_counter_fast(mm, member) dec_mm_counter(mm, member) @@ -191,8 +191,128 @@ static void check_sync_rss_stat(struct task_struct *task) { } +#endif /* SPLIT_RSS_COUNTING */ + +#ifdef HAVE_GENERIC_MMU_GATHER + +static int tlb_next_batch(struct mmu_gather *tlb) +{ + struct mmu_gather_batch *batch; + + batch = tlb->active; + if (batch->next) { + tlb->active = batch->next; + return 1; + } + + batch = (void *)__get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0); + if (!batch) + return 0; + + batch->next = NULL; + batch->nr = 0; + batch->max = MAX_GATHER_BATCH; + + tlb->active->next = batch; + tlb->active = batch; + + return 1; +} + +/* tlb_gather_mmu + * Called to initialize an (on-stack) mmu_gather structure for page-table + * tear-down from @mm. The @fullmm argument is used when @mm is without + * users and we're going to destroy the full address space (exit/execve). + */ +void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, bool fullmm) +{ + tlb->mm = mm; + + tlb->fullmm = fullmm; + tlb->need_flush = 0; + tlb->fast_mode = (num_possible_cpus() == 1); + tlb->local.next = NULL; + tlb->local.nr = 0; + tlb->local.max = ARRAY_SIZE(tlb->__pages); + tlb->active = &tlb->local; + +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + tlb->batch = NULL; +#endif +} + +void tlb_flush_mmu(struct mmu_gather *tlb) +{ + struct mmu_gather_batch *batch; + + if (!tlb->need_flush) + return; + tlb->need_flush = 0; + tlb_flush(tlb); +#ifdef CONFIG_HAVE_RCU_TABLE_FREE + tlb_table_flush(tlb); #endif + if (tlb_fast_mode(tlb)) + return; + + for (batch = &tlb->local; batch; batch = batch->next) { + free_pages_and_swap_cache(batch->pages, batch->nr); + batch->nr = 0; + } + tlb->active = &tlb->local; +} + +/* tlb_finish_mmu + * Called at the end of the shootdown operation to free up any resources + * that were required. + */ +void tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end) +{ + struct mmu_gather_batch *batch, *next; + + tlb_flush_mmu(tlb); + + /* keep the page table cache within bounds */ + check_pgt_cache(); + + for (batch = tlb->local.next; batch; batch = next) { + next = batch->next; + free_pages((unsigned long)batch, 0); + } + tlb->local.next = NULL; +} + +/* __tlb_remove_page + * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while + * handling the additional races in SMP caused by other CPUs caching valid + * mappings in their TLBs. Returns the number of free page slots left. + * When out of page slots we must call tlb_flush_mmu(). + */ +int __tlb_remove_page(struct mmu_gather *tlb, struct page *page) +{ + struct mmu_gather_batch *batch; + + tlb->need_flush = 1; + + if (tlb_fast_mode(tlb)) { + free_page_and_swap_cache(page); + return 1; /* avoid calling tlb_flush_mmu() */ + } + + batch = tlb->active; + batch->pages[batch->nr++] = page; + if (batch->nr == batch->max) { + if (!tlb_next_batch(tlb)) + return 0; + } + VM_BUG_ON(batch->nr > batch->max); + + return batch->max - batch->nr; +} + +#endif /* HAVE_GENERIC_MMU_GATHER */ + #ifdef CONFIG_HAVE_RCU_TABLE_FREE /* @@ -268,7 +388,7 @@ void tlb_remove_table(struct mmu_gather *tlb, void *table) tlb_table_flush(tlb); } -#endif +#endif /* CONFIG_HAVE_RCU_TABLE_FREE */ /* * If a p?d_bad entry is found while walking page tables, report -- cgit v1.2.3 From ca16d140af91febe25daeb9e032bf8bd46b8c31f Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Thu, 26 May 2011 19:16:19 +0900 Subject: mm: don't access vm_flags as 'int' The type of vma->vm_flags is 'unsigned long'. Neither 'int' nor 'unsigned int'. This patch fixes such misuse. Signed-off-by: KOSAKI Motohiro [ Changed to use a typedef - we'll extend it to cover more cases later, since there has been discussion about making it a 64-bit type.. - Linus ] Signed-off-by: Linus Torvalds --- fs/hugetlbfs/inode.c | 3 ++- fs/proc/task_mmu.c | 2 +- include/linux/hugetlb.h | 6 +++--- include/linux/hugetlb_inline.h | 2 +- include/linux/mm.h | 6 +++--- include/linux/mm_types.h | 4 +++- ipc/shm.c | 2 +- mm/fremap.c | 2 +- mm/hugetlb.c | 4 ++-- mm/memory.c | 2 +- mm/mlock.c | 8 ++++---- mm/mmap.c | 8 ++++---- 12 files changed, 26 insertions(+), 23 deletions(-) (limited to 'mm/memory.c') diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index e7a035781b7d..7aafeb8fa300 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -921,7 +921,8 @@ static int can_do_hugetlb_shm(void) return capable(CAP_IPC_LOCK) || in_group_p(sysctl_hugetlb_shm_group); } -struct file *hugetlb_file_setup(const char *name, size_t size, int acctflag, +struct file *hugetlb_file_setup(const char *name, size_t size, + vm_flags_t acctflag, struct user_struct **user, int creat_flags) { int error = -ENOMEM; diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 2c9db29ea358..db15935fa757 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -211,7 +211,7 @@ static void show_map_vma(struct seq_file *m, struct vm_area_struct *vma) { struct mm_struct *mm = vma->vm_mm; struct file *file = vma->vm_file; - int flags = vma->vm_flags; + vm_flags_t flags = vma->vm_flags; unsigned long ino = 0; unsigned long long pgoff = 0; unsigned long start, end; diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 943c76b3d4bb..cf8931e1dd9d 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -41,7 +41,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, unsigned int flags); int hugetlb_reserve_pages(struct inode *inode, long from, long to, struct vm_area_struct *vma, - int acctflags); + vm_flags_t vm_flags); void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed); int dequeue_hwpoisoned_huge_page(struct page *page); void copy_huge_page(struct page *dst, struct page *src); @@ -168,7 +168,7 @@ static inline struct hugetlbfs_sb_info *HUGETLBFS_SB(struct super_block *sb) extern const struct file_operations hugetlbfs_file_operations; extern const struct vm_operations_struct hugetlb_vm_ops; -struct file *hugetlb_file_setup(const char *name, size_t size, int acct, +struct file *hugetlb_file_setup(const char *name, size_t size, vm_flags_t acct, struct user_struct **user, int creat_flags); int hugetlb_get_quota(struct address_space *mapping, long delta); void hugetlb_put_quota(struct address_space *mapping, long delta); @@ -192,7 +192,7 @@ static inline void set_file_hugepages(struct file *file) #define is_file_hugepages(file) 0 #define set_file_hugepages(file) BUG() static inline struct file *hugetlb_file_setup(const char *name, size_t size, - int acctflag, struct user_struct **user, int creat_flags) + vm_flags_t acctflag, struct user_struct **user, int creat_flags) { return ERR_PTR(-ENOSYS); } diff --git a/include/linux/hugetlb_inline.h b/include/linux/hugetlb_inline.h index 6931489a5c14..2bb681fbeb35 100644 --- a/include/linux/hugetlb_inline.h +++ b/include/linux/hugetlb_inline.h @@ -7,7 +7,7 @@ static inline int is_vm_hugetlb_page(struct vm_area_struct *vma) { - return vma->vm_flags & VM_HUGETLB; + return !!(vma->vm_flags & VM_HUGETLB); } #else diff --git a/include/linux/mm.h b/include/linux/mm.h index 8eb969ebf904..fb8e814f78dc 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -165,12 +165,12 @@ extern pgprot_t protection_map[16]; */ static inline int is_linear_pfn_mapping(struct vm_area_struct *vma) { - return (vma->vm_flags & VM_PFN_AT_MMAP); + return !!(vma->vm_flags & VM_PFN_AT_MMAP); } static inline int is_pfn_mapping(struct vm_area_struct *vma) { - return (vma->vm_flags & VM_PFNMAP); + return !!(vma->vm_flags & VM_PFNMAP); } /* @@ -1432,7 +1432,7 @@ extern unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, unsigned long flag, unsigned long pgoff); extern unsigned long mmap_region(struct file *file, unsigned long addr, unsigned long len, unsigned long flags, - unsigned int vm_flags, unsigned long pgoff); + vm_flags_t vm_flags, unsigned long pgoff); static inline unsigned long do_mmap(struct file *file, unsigned long addr, unsigned long len, unsigned long prot, diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 071d459e866b..6fe96c19f85e 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -102,6 +102,8 @@ struct page { #endif }; +typedef unsigned long __nocast vm_flags_t; + /* * A region containing a mapping of a non-memory backed file under NOMMU * conditions. These are held in a global tree and are pinned by the VMAs that @@ -109,7 +111,7 @@ struct page { */ struct vm_region { struct rb_node vm_rb; /* link in global region tree */ - unsigned long vm_flags; /* VMA vm_flags */ + vm_flags_t vm_flags; /* VMA vm_flags */ unsigned long vm_start; /* start address of region */ unsigned long vm_end; /* region initialised to here */ unsigned long vm_top; /* region allocated to here */ diff --git a/ipc/shm.c b/ipc/shm.c index 729acb7e3148..ab3385a21b27 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -347,7 +347,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) struct file * file; char name[13]; int id; - int acctflag = 0; + vm_flags_t acctflag = 0; if (size < SHMMIN || size > ns->shm_ctlmax) return -EINVAL; diff --git a/mm/fremap.c b/mm/fremap.c index 7f4123056e06..b8e0e2d468af 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -224,7 +224,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, /* * drop PG_Mlocked flag for over-mapped range */ - unsigned int saved_flags = vma->vm_flags; + vm_flags_t saved_flags = vma->vm_flags; munlock_vma_pages_range(vma, start, start + size); vma->vm_flags = saved_flags; } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5fd68b95c671..f33bb319b73f 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2833,7 +2833,7 @@ void hugetlb_change_protection(struct vm_area_struct *vma, int hugetlb_reserve_pages(struct inode *inode, long from, long to, struct vm_area_struct *vma, - int acctflag) + vm_flags_t vm_flags) { long ret, chg; struct hstate *h = hstate_inode(inode); @@ -2843,7 +2843,7 @@ int hugetlb_reserve_pages(struct inode *inode, * attempt will be made for VM_NORESERVE to allocate a page * and filesystem quota without using reserves */ - if (acctflag & VM_NORESERVE) + if (vm_flags & VM_NORESERVE) return 0; /* diff --git a/mm/memory.c b/mm/memory.c index b73f677f0bb1..fc24f7d788bd 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -730,7 +730,7 @@ static void print_bad_pte(struct vm_area_struct *vma, unsigned long addr, add_taint(TAINT_BAD_PAGE); } -static inline int is_cow_mapping(unsigned int flags) +static inline int is_cow_mapping(vm_flags_t flags) { return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE; } diff --git a/mm/mlock.c b/mm/mlock.c index 516b2c2ddd5a..048260c4e02e 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -307,13 +307,13 @@ void munlock_vma_pages_range(struct vm_area_struct *vma, * For vmas that pass the filters, merge/split as appropriate. */ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, - unsigned long start, unsigned long end, unsigned int newflags) + unsigned long start, unsigned long end, vm_flags_t newflags) { struct mm_struct *mm = vma->vm_mm; pgoff_t pgoff; int nr_pages; int ret = 0; - int lock = newflags & VM_LOCKED; + int lock = !!(newflags & VM_LOCKED); if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) || is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm)) @@ -385,7 +385,7 @@ static int do_mlock(unsigned long start, size_t len, int on) prev = vma; for (nstart = start ; ; ) { - unsigned int newflags; + vm_flags_t newflags; /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ @@ -524,7 +524,7 @@ static int do_mlockall(int flags) goto out; for (vma = current->mm->mmap; vma ; vma = prev->vm_next) { - unsigned int newflags; + vm_flags_t newflags; newflags = vma->vm_flags | VM_LOCKED; if (!(flags & MCL_CURRENT)) diff --git a/mm/mmap.c b/mm/mmap.c index ac2631b7477f..bbdc9af5e117 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -960,7 +960,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, { struct mm_struct * mm = current->mm; struct inode *inode; - unsigned int vm_flags; + vm_flags_t vm_flags; int error; unsigned long reqprot = prot; @@ -1165,7 +1165,7 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg) */ int vma_wants_writenotify(struct vm_area_struct *vma) { - unsigned int vm_flags = vma->vm_flags; + vm_flags_t vm_flags = vma->vm_flags; /* If it was private or non-writable, the write bit is already clear */ if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED))) @@ -1193,7 +1193,7 @@ int vma_wants_writenotify(struct vm_area_struct *vma) * We account for memory if it's a private writeable mapping, * not hugepages and VM_NORESERVE wasn't set. */ -static inline int accountable_mapping(struct file *file, unsigned int vm_flags) +static inline int accountable_mapping(struct file *file, vm_flags_t vm_flags) { /* * hugetlb has its own accounting separate from the core VM @@ -1207,7 +1207,7 @@ static inline int accountable_mapping(struct file *file, unsigned int vm_flags) unsigned long mmap_region(struct file *file, unsigned long addr, unsigned long len, unsigned long flags, - unsigned int vm_flags, unsigned long pgoff) + vm_flags_t vm_flags, unsigned long pgoff) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; -- cgit v1.2.3 From 456f998ec817ebfa254464be4f089542fa390645 Mon Sep 17 00:00:00 2001 From: Ying Han Date: Thu, 26 May 2011 16:25:38 -0700 Subject: memcg: add the pagefault count into memcg stats Two new stats in per-memcg memory.stat which tracks the number of page faults and number of major page faults. "pgfault" "pgmajfault" They are different from "pgpgin"/"pgpgout" stat which count number of pages charged/discharged to the cgroup and have no meaning of reading/ writing page to disk. It is valuable to track the two stats for both measuring application's performance as well as the efficiency of the kernel page reclaim path. Counting pagefaults per process is useful, but we also need the aggregated value since processes are monitored and controlled in cgroup basis in memcg. Functional test: check the total number of pgfault/pgmajfault of all memcgs and compare with global vmstat value: $ cat /proc/vmstat | grep fault pgfault 1070751 pgmajfault 553 $ cat /dev/cgroup/memory.stat | grep fault pgfault 1071138 pgmajfault 553 total_pgfault 1071142 total_pgmajfault 553 $ cat /dev/cgroup/A/memory.stat | grep fault pgfault 199 pgmajfault 0 total_pgfault 199 total_pgmajfault 0 Performance test: run page fault test(pft) wit 16 thread on faulting in 15G anon pages in 16G container. There is no regression noticed on the "flt/cpu/s" Sample output from pft: TAG pft:anon-sys-default: Gb Thr CLine User System Wall flt/cpu/s fault/wsec 15 16 1 0.67s 233.41s 14.76s 16798.546 266356.260 +-------------------------------------------------------------------------+ N Min Max Median Avg Stddev x 10 16682.962 17344.027 16913.524 16928.812 166.5362 + 10 16695.568 16923.896 16820.604 16824.652 84.816568 No difference proven at 95.0% confidence [akpm@linux-foundation.org: fix build] [hughd@google.com: shmem fix] Signed-off-by: Ying Han Acked-by: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Reviewed-by: Minchan Kim Cc: Daisuke Nishimura Acked-by: Balbir Singh Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ncpfs/mmap.c | 2 ++ include/linux/memcontrol.h | 7 +++++++ mm/filemap.c | 1 + mm/memcontrol.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++ mm/memory.c | 2 ++ mm/shmem.c | 11 ++++++----- 6 files changed, 65 insertions(+), 5 deletions(-) (limited to 'mm/memory.c') diff --git a/fs/ncpfs/mmap.c b/fs/ncpfs/mmap.c index a7c07b44b100..e5d71b27a5b0 100644 --- a/fs/ncpfs/mmap.c +++ b/fs/ncpfs/mmap.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -92,6 +93,7 @@ static int ncp_file_mmap_fault(struct vm_area_struct *area, * -- wli */ count_vm_event(PGMAJFAULT); + mem_cgroup_count_vm_event(area->vm_mm, PGMAJFAULT); return VM_FAULT_MAJOR; } diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index ac1e5d20916a..9724a38ee69d 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -20,6 +20,8 @@ #ifndef _LINUX_MEMCONTROL_H #define _LINUX_MEMCONTROL_H #include +#include + struct mem_cgroup; struct page_cgroup; struct page; @@ -149,6 +151,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, unsigned long *total_scanned); u64 mem_cgroup_get_limit(struct mem_cgroup *mem); +void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx); #ifdef CONFIG_TRANSPARENT_HUGEPAGE void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail); #endif @@ -357,6 +360,10 @@ static inline void mem_cgroup_split_huge_fixup(struct page *head, { } +static inline +void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) +{ +} #endif /* CONFIG_CGROUP_MEM_CONT */ #if !defined(CONFIG_CGROUP_MEM_RES_CTLR) || !defined(CONFIG_DEBUG_VM) diff --git a/mm/filemap.c b/mm/filemap.c index 7455ccd8bda8..bcdc393b6580 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1661,6 +1661,7 @@ int filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) /* No page in the page cache at all */ do_sync_mmap_readahead(vma, ra, file, offset); count_vm_event(PGMAJFAULT); + mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); ret = VM_FAULT_MAJOR; retry_find: page = find_get_page(mapping, offset); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4021fcd71b60..bd9052a5d3ad 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -94,6 +94,8 @@ enum mem_cgroup_events_index { MEM_CGROUP_EVENTS_PGPGIN, /* # of pages paged in */ MEM_CGROUP_EVENTS_PGPGOUT, /* # of pages paged out */ MEM_CGROUP_EVENTS_COUNT, /* # of pages paged in/out */ + MEM_CGROUP_EVENTS_PGFAULT, /* # of page-faults */ + MEM_CGROUP_EVENTS_PGMAJFAULT, /* # of major page-faults */ MEM_CGROUP_EVENTS_NSTATS, }; /* @@ -590,6 +592,16 @@ static void mem_cgroup_swap_statistics(struct mem_cgroup *mem, this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val); } +void mem_cgroup_pgfault(struct mem_cgroup *mem, int val) +{ + this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_PGFAULT], val); +} + +void mem_cgroup_pgmajfault(struct mem_cgroup *mem, int val) +{ + this_cpu_add(mem->stat->events[MEM_CGROUP_EVENTS_PGMAJFAULT], val); +} + static unsigned long mem_cgroup_read_events(struct mem_cgroup *mem, enum mem_cgroup_events_index idx) { @@ -827,6 +839,33 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup *mem) return (mem == root_mem_cgroup); } +void mem_cgroup_count_vm_event(struct mm_struct *mm, enum vm_event_item idx) +{ + struct mem_cgroup *mem; + + if (!mm) + return; + + rcu_read_lock(); + mem = mem_cgroup_from_task(rcu_dereference(mm->owner)); + if (unlikely(!mem)) + goto out; + + switch (idx) { + case PGMAJFAULT: + mem_cgroup_pgmajfault(mem, 1); + break; + case PGFAULT: + mem_cgroup_pgfault(mem, 1); + break; + default: + BUG(); + } +out: + rcu_read_unlock(); +} +EXPORT_SYMBOL(mem_cgroup_count_vm_event); + /* * Following LRU functions are allowed to be used without PCG_LOCK. * Operations are called by routine of global LRU independently from memcg. @@ -3958,6 +3997,8 @@ enum { MCS_PGPGIN, MCS_PGPGOUT, MCS_SWAP, + MCS_PGFAULT, + MCS_PGMAJFAULT, MCS_INACTIVE_ANON, MCS_ACTIVE_ANON, MCS_INACTIVE_FILE, @@ -3980,6 +4021,8 @@ struct { {"pgpgin", "total_pgpgin"}, {"pgpgout", "total_pgpgout"}, {"swap", "total_swap"}, + {"pgfault", "total_pgfault"}, + {"pgmajfault", "total_pgmajfault"}, {"inactive_anon", "total_inactive_anon"}, {"active_anon", "total_active_anon"}, {"inactive_file", "total_inactive_file"}, @@ -4008,6 +4051,10 @@ mem_cgroup_get_local_stat(struct mem_cgroup *mem, struct mcs_total_stat *s) val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT); s->stat[MCS_SWAP] += val * PAGE_SIZE; } + val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGFAULT); + s->stat[MCS_PGFAULT] += val; + val = mem_cgroup_read_events(mem, MEM_CGROUP_EVENTS_PGMAJFAULT); + s->stat[MCS_PGMAJFAULT] += val; /* per zone stat */ val = mem_cgroup_get_local_zonestat(mem, LRU_INACTIVE_ANON); diff --git a/mm/memory.c b/mm/memory.c index fc24f7d788bd..6953d3926e01 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2874,6 +2874,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma, /* Had to read the page from swap area: Major fault */ ret = VM_FAULT_MAJOR; count_vm_event(PGMAJFAULT); + mem_cgroup_count_vm_event(mm, PGMAJFAULT); } else if (PageHWPoison(page)) { /* * hwpoisoned dirty swapcache pages are kept for killing @@ -3413,6 +3414,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma, __set_current_state(TASK_RUNNING); count_vm_event(PGFAULT); + mem_cgroup_count_vm_event(mm, PGFAULT); /* do counter updates before entering really critical section. */ check_sync_rss_stat(current); diff --git a/mm/shmem.c b/mm/shmem.c index 69edb45a9f28..1acfb2687bfa 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1305,12 +1305,10 @@ repeat: swappage = lookup_swap_cache(swap); if (!swappage) { shmem_swp_unmap(entry); + spin_unlock(&info->lock); /* here we actually do the io */ - if (type && !(*type & VM_FAULT_MAJOR)) { - __count_vm_event(PGMAJFAULT); + if (type) *type |= VM_FAULT_MAJOR; - } - spin_unlock(&info->lock); swappage = shmem_swapin(swap, gfp, info, idx); if (!swappage) { spin_lock(&info->lock); @@ -1549,7 +1547,10 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf) error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret); if (error) return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS); - + if (ret & VM_FAULT_MAJOR) { + count_vm_event(PGMAJFAULT); + mem_cgroup_count_vm_event(vma->vm_mm, PGMAJFAULT); + } return ret | VM_FAULT_LOCKED; } -- cgit v1.2.3 From 0164f69d0cf1a6abbc936851f5b72ece92187cda Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Wed, 15 Jun 2011 15:08:09 -0700 Subject: mm/memory.c: fix kernel-doc notation Fix new kernel-doc warnings in mm/memory.c: Warning(mm/memory.c:1327): No description found for parameter 'tlb' Warning(mm/memory.c:1327): Excess function parameter 'tlbp' description in 'unmap_vmas' Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index 6953d3926e01..b13e7dbc399b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1296,7 +1296,7 @@ static unsigned long unmap_page_range(struct mmu_gather *tlb, /** * unmap_vmas - unmap a range of memory covered by a list of vma's - * @tlbp: address of the caller's struct mmu_gather + * @tlb: address of the caller's struct mmu_gather * @vma: the starting vma * @start_addr: virtual address at which to start unmapping * @end_addr: virtual address at which to end unmapping -- cgit v1.2.3 From 5f1a19070b16c20cdc71ed0e981bfa19f8f6a4ee Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 15 Jun 2011 15:08:23 -0700 Subject: mm: fix wrong kunmap_atomic() pointer Running a ktest.pl test, I hit the following bug on x86_32: ------------[ cut here ]------------ WARNING: at arch/x86/mm/highmem_32.c:81 __kunmap_atomic+0x64/0xc1() Hardware name: Modules linked in: Pid: 93, comm: sh Not tainted 2.6.39-test+ #1 Call Trace: [] warn_slowpath_common+0x7c/0x91 [] ? __kunmap_atomic+0x64/0xc1 [] ? __kunmap_atomic+0x64/0xc1^M [] warn_slowpath_null+0x22/0x24 [] __kunmap_atomic+0x64/0xc1 [] unmap_vmas+0x43a/0x4e0 [] exit_mmap+0x91/0xd2 [] mmput+0x43/0xad [] exit_mm+0x111/0x119 [] do_exit+0x1ff/0x5fa [] ? set_current_blocked+0x3c/0x40 [] ? sigprocmask+0x7e/0x8e [] do_group_exit+0x65/0x88 [] sys_exit_group+0x18/0x1c [] sysenter_do_call+0x12/0x38 ---[ end trace 8055f74ea3c0eb62 ]--- Running a ktest.pl git bisect, found the culprit: commit e303297e6c3a ("mm: extended batches for generic mmu_gather") But although this was the commit triggering the bug, it was not the one originally responsible for the bug. That was commit d16dfc550f53 ("mm: mmu_gather rework"). The code in zap_pte_range() has something that looks like the following: pte = pte_offset_map_lock(mm, pmd, addr, &ptl); do { [...] } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(pte - 1, ptl); The pte starts off pointing at the first element in the page table directory that was returned by the pte_offset_map_lock(). When it's done with the page, pte will be pointing to anything between the next entry and the first entry of the next page inclusive. By doing a pte - 1, this puts the pte back onto the original page, which is all that pte_unmap_unlock() needs. In most archs (64 bit), this is not an issue as the pte is ignored in the pte_unmap_unlock(). But on 32 bit archs, where things may be kmapped, it is essential that the pte passed to pte_unmap_unlock() resides on the same page that was given by pte_offest_map_lock(). The problem came in d16dfc55 ("mm: mmu_gather rework") where it introduced a "break;" from the while loop. This alone did not seem to easily trigger the bug. But the modifications made by e303297e6 caused that "break;" to be hit on the first iteration, before the pte++. The pte not being incremented will now cause pte_unmap_unlock(pte - 1) to be pointing to the previous page. This will cause the wrong page to be unmapped, and also trigger the warning above. The simple solution is to just save the pointer given by pte_offset_map_lock() and use it in the unlock. Signed-off-by: Steven Rostedt Cc: Peter Zijlstra Cc: KAMEZAWA Hiroyuki Acked-by: Hugh Dickins Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index b13e7dbc399b..87d935333f0d 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1112,11 +1112,13 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb, int force_flush = 0; int rss[NR_MM_COUNTERS]; spinlock_t *ptl; + pte_t *start_pte; pte_t *pte; again: init_rss_vec(rss); - pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + pte = start_pte; arch_enter_lazy_mmu_mode(); do { pte_t ptent = *pte; @@ -1196,7 +1198,7 @@ again: add_mm_rss_vec(mm, rss); arch_leave_lazy_mmu_mode(); - pte_unmap_unlock(pte - 1, ptl); + pte_unmap_unlock(start_pte, ptl); /* * mmu_gather ran out of room to batch pages, we break out of -- cgit v1.2.3