kernel/linux.git/arch/arc/mm, branch v6.1.168

mm/fault: convert remaining simple cases to lock_mm_and_find_vma()

2023-07-01T11:16:25+00:00

commit a050ba1e7422f2cc60ff8bfde3f96d34d00cb585 upstream. This does the simple pattern conversion of alpha, arc, csky, hexagon, loongarch, nios2, sh, sparc32, and xtensa to the lock_mm_and_find_vma() helper. They all have the regular fault handling pattern without odd special cases. The remaining architectures all have something that keeps us from a straightforward conversion: ia64 and parisc have stacks that can grow both up as well as down (and ia64 has special address region checks). And m68k, microblaze, openrisc, sparc64, and um end up having extra rules about only expanding the stack down a limited amount below the user space stack pointer. That is something that x86 used to do too (long long ago), and it probably could just be skipped, but it still makes the conversion less than trivial. Note that this conversion was done manually and with the exception of alpha without any build testing, because I have a fairly limited cross- building environment. The cases are all simple, and I went through the changes several times, but... Signed-off-by: Linus Torvalds Signed-off-by: Samuel Mendoza-Jonas Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman

arc: iounmap() arg is volatile

2022-10-17T23:32:12+00:00

Add 'volatile' to iounmap()'s argument to prevent build warnings. This make it the same as other major architectures. Placates these warnings: (12 such warnings) ../drivers/video/fbdev/riva/fbdev.c: In function 'rivafb_probe': ../drivers/video/fbdev/riva/fbdev.c:2067:42: error: passing argument 1 of 'iounmap' discards 'volatile' qualifier from pointer target type [-Werror=discarded-qualifiers] 2067 | iounmap(default_par->riva.PRAMIN); Fixes: 1162b0701b14b ("ARC: I/O and DMA Mappings") Signed-off-by: Randy Dunlap Cc: Vineet Gupta Cc: linux-snps-arc@lists.infradead.org Cc: Arnd Bergmann Signed-off-by: Vineet Gupta

ARC: Fix comment typo

2022-10-17T23:32:11+00:00

- Remove one of the repeated 'call' in comment line 396. - Delete the redundant word 'to', 'since' Signed-off-by: Jilin Yuan Signed-off-by: Vineet Gupta

arc/mm: enable ARCH_HAS_VM_GET_PAGE_PROT

2022-07-18T00:14:40+00:00

This enables ARCH_HAS_VM_GET_PAGE_PROT on the platform and exports standard vm_get_page_prot() implementation via DECLARE_VM_GET_PAGE_PROT, which looks up a private and static protection_map[] array. Subsequently all __SXXX and __PXXX macros can be dropped which are no longer needed. Link: https://lkml.kernel.org/r/20220711070600.2378316-23-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Cc: Vineet Gupta Cc: Arnd Bergmann Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Christoph Hellwig Cc: Christoph Hellwig Cc: Chris Zankel Cc: "David S. Miller" Cc: Dinh Nguyen Cc: Geert Uytterhoeven Cc: Guo Ren Cc: Heiko Carstens Cc: Huacai Chen Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Jeff Dike Cc: Jonas Bonn Cc: Michael Ellerman Cc: Michal Simek Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Richard Henderson Cc: Rich Felker Cc: Russell King Cc: Sam Ravnborg Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: WANG Xuerui Cc: Will Deacon Cc: Yoshinori Sato Signed-off-by: Andrew Morton

mm: avoid unnecessary page fault retires on shared memory types

2022-06-17T02:48:27+00:00

I observed that for each of the shared file-backed page faults, we're very likely to retry one more time for the 1st write fault upon no page. It's because we'll need to release the mmap lock for dirty rate limit purpose with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()). Then after that throttling we return VM_FAULT_RETRY. We did that probably because VM_FAULT_RETRY is the only way we can return to the fault handler at that time telling it we've released the mmap lock. However that's not ideal because it's very likely the fault does not need to be retried at all since the pgtable was well installed before the throttling, so the next continuous fault (including taking mmap read lock, walk the pgtable, etc.) could be in most cases unnecessary. It's not only slowing down page faults for shared file-backed, but also add more mmap lock contention which is in most cases not needed at all. To observe this, one could try to write to some shmem page and look at "pgfault" value in /proc/vmstat, then we should expect 2 counts for each shmem write simply because we retried, and vm event "pgfault" will capture that. To make it more efficient, add a new VM_FAULT_COMPLETED return code just to show that we've completed the whole fault and released the lock. It's also a hint that we should very possibly not need another fault immediately on this page because we've just completed it. This patch provides a ~12% perf boost on my aarch64 test VM with a simple program sequentially dirtying 400MB shmem file being mmap()ed and these are the time it needs: Before: 650.980 ms (+-1.94%) After: 569.396 ms (+-1.38%) I believe it could help more than that. We need some special care on GUP and the s390 pgfault handler (for gmap code before returning from pgfault), the rest changes in the page fault handlers should be relatively straightforward. Another thing to mention is that mm_account_fault() does take this new fault as a generic fault to be accounted, unlike VM_FAULT_RETRY. I explicitly didn't touch hmm_vma_fault() and break_ksm() because they do not handle VM_FAULT_RETRY even with existing code, so I'm literally keeping them as-is. Link: https://lkml.kernel.org/r/20220530183450.42886-1-peterx@redhat.com Signed-off-by: Peter Xu Acked-by: Geert Uytterhoeven Acked-by: Peter Zijlstra (Intel) Acked-by: Johannes Weiner Acked-by: Vineet Gupta Acked-by: Guo Ren Acked-by: Max Filippov Acked-by: Christian Borntraeger Acked-by: Michael Ellerman (powerpc) Acked-by: Catalin Marinas Reviewed-by: Alistair Popple Reviewed-by: Ingo Molnar Acked-by: Russell King (Oracle) [arm part] Acked-by: Heiko Carstens Cc: Vasily Gorbik Cc: Stafford Horne Cc: David S. Miller Cc: Johannes Berg Cc: Brian Cain Cc: Richard Henderson Cc: Richard Weinberger Cc: Benjamin Herrenschmidt Cc: Thomas Gleixner Cc: Janosch Frank Cc: Albert Ou Cc: Anton Ivanov Cc: Dave Hansen Cc: Borislav Petkov Cc: Sven Schnelle Cc: Andrea Arcangeli Cc: James Bottomley Cc: Al Viro Cc: Alexander Gordeev Cc: Jonas Bonn Cc: Will Deacon Cc: Vlastimil Babka Cc: Michal Simek Cc: Matt Turner Cc: Paul Mackerras Cc: David Hildenbrand Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Stefan Kristiansson Cc: Paul Walmsley Cc: Ivan Kokshaysky Cc: Chris Zankel Cc: Hugh Dickins Cc: Dinh Nguyen Cc: Rich Felker Cc: H. Peter Anvin Cc: Andy Lutomirski Cc: Thomas Bogendoerfer Cc: Helge Deller Cc: Yoshinori Sato Signed-off-by: Andrew Morton

ARC: fix typos in comments

2022-04-18T19:20:23+00:00

Various spelling mistakes in comments. Detected with the help of Coccinelle. Signed-off-by: Julia Lawall Signed-off-by: Vineet Gupta

Merge tag 'arc-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2022-01-18T04:36:35+00:00

Pull ARC fixes from Vineet Gupta: "Nothing too exciting for now" * tag 'arc-5.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: arc: use swap() to make code cleaner arc: perf: Move static structs to where they're really used ARC: perf: fix misleading comment about pmu vs counter stop arc: Replace lkml.org links with lore ARC: perf: Remove redundant initialization of variable idx ARC: thread_info.h: correct two typos in a comment

mm: remove redundant check about FAULT_FLAG_ALLOW_RETRY bit

2022-01-15T14:30:27+00:00

Since commit 4064b9827063 ("mm: allow VM_FAULT_RETRY for multiple times") allowed VM_FAULT_RETRY for multiple times, the FAULT_FLAG_ALLOW_RETRY bit of fault_flag will not be changed in the page fault path, so the following check is no longer needed: flags & FAULT_FLAG_ALLOW_RETRY So just remove it. [akpm@linux-foundation.org: coding style fixes] Link: https://lkml.kernel.org/r/20211110123358.36511-1-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Cc: Peter Zijlstra Cc: Ingo Molnar Cc: David Hildenbrand Cc: Kirill Shutemov Cc: Peter Xu Cc: Muchun Song Cc: Chengming Zhou Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

arc: Replace lkml.org links with lore

2021-12-29T03:48:49+00:00

As started by commit 05a5f51ca566 ("Documentation: Replace lkml.org links with lore"), replace lkml.org links with lore to better use a single source that's more likely to stay available long-term. Signed-off-by: Kees Cook Signed-off-by: Vineet Gupta

memblock: allow to specify flags with memblock_add_node()

2021-11-06T20:30:42+00:00

We want to specify flags when hotplugging memory. Let's prepare to pass flags to memblock_add_node() by adjusting all existing users. Note that when hotplugging memory the system is already up and running and we might have concurrent memblock users: for example, while we're hotplugging memory, kexec_file code might search for suitable memory regions to place kexec images. It's important to add the memory directly to memblock via a single call with the right flags, instead of adding the memory first and apply flags later: otherwise, concurrent memblock users might temporarily stumble over memblocks with wrong flags, which will be important in a follow-up patch that introduces a new flag to properly handle add_memory_driver_managed(). Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com Acked-by: Geert Uytterhoeven Acked-by: Heiko Carstens Signed-off-by: David Hildenbrand Acked-by: Shahab Vahedi [arch/arc] Reviewed-by: Mike Rapoport Cc: "Aneesh Kumar K . V" Cc: Arnd Bergmann Cc: Christian Borntraeger Cc: Eric Biederman Cc: Huacai Chen Cc: Jianyong Wu Cc: Jiaxun Yang Cc: Michal Hocko Cc: Oscar Salvador Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds