kernel/linux.git/include/trace/events/mmflags.h, branch v6.12.80

tracing: gfp: Fix the GFP enum values shown for user space tracing tools

2025-01-23T16:23:02+00:00

commit 60295b944ff6805e677c48ae4178532b207d43be upstream. Tracing tools like perf and trace-cmd read the /sys/kernel/tracing/events/*/*/format files to know how to parse the data and also how to print it. For the "print fmt" portion of that file, if anything uses an enum that is not exported to the tracing system, user space will not be able to parse it. The GFP flags use to be defines, and defines get translated in the print fmt sections. But now they are converted to use enums, which is not. The mm_page_alloc trace event format use to have: print fmt: "page=%p pfn=0x%lx order=%d migratetype=%d gfp_flags=%s", REC->pfn != -1UL ? (((struct page *)vmemmap_base) + (REC->pfn)) : ((void *)0), REC->pfn != -1UL ? REC->pfn : 0, REC->order, REC->migratetype, (REC->gfp_flags) ? __print_flags(REC->gfp_flags, "|", {( unsigned long)(((((((( gfp_t)(0x400u|0x800u)) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x100000u)) | (( gfp_t)0x02u)) | (( gfp_t)0x08u) | (( gfp_t)0)) | (( gfp_t)0x40000u) | (( gfp_t)0x80000u) | (( gfp_t)0x2000u)) & ~(( gfp_t)(0x400u|0x800u))) | (( gfp_t)0x400u)), "GFP_TRANSHUGE"}, {( unsigned long)((((((( gfp_t)(0x400u|0x800u)) | (( gfp_t)0x40u) | (( gfp_t)0x80u) | (( gfp_t)0x100000u)) | (( gfp_t)0x02u)) | (( gfp_t)0x08u) | (( gfp_t)0)) ... Where the GFP values are shown and not their names. But after the GFP flags were converted to use enums, it has: print fmt: "page=%p pfn=0x%lx order=%d migratetype=%d gfp_flags=%s", REC->pfn != -1UL ? (vmemmap + (REC->pfn)) : ((void *)0), REC->pfn != -1UL ? REC->pfn : 0, REC->order, REC->migratetype, (REC->gfp_flags) ? __print_flags(REC->gfp_flags, "|", {( unsigned long)(((((((( gfp_t)(((((1UL))) << (___GFP_DIRECT_RECLAIM_BIT))|((((1UL))) << (___GFP_KSWAPD_RECLAIM_BIT)))) | (( gfp_t)((((1UL))) << (___GFP_IO_BIT))) | (( gfp_t)((((1UL))) << (___GFP_FS_BIT))) | (( gfp_t)((((1UL))) << (___GFP_HARDWALL_BIT)))) | (( gfp_t)((((1UL))) << (___GFP_HIGHMEM_BIT)))) | (( gfp_t)((((1UL))) << (___GFP_MOVABLE_BIT))) | (( gfp_t)0)) | (( gfp_t)((((1UL))) << (___GFP_COMP_BIT))) ... Where the enums names like ___GFP_KSWAPD_RECLAIM_BIT are shown and not their values. User space has no way to convert these names to their values and the output will fail to parse. What is shown is now: mm_page_alloc: page=0xffffffff981685f3 pfn=0x1d1ac1 order=0 migratetype=1 gfp_flags=0x140cca The TRACE_DEFINE_ENUM() macro was created to handle enums in the print fmt files. This causes them to be replaced at boot up with the numbers, so that user space tooling can parse it. By using this macro, the output is back to the human readable: mm_page_alloc: page=0xffffffff981685f3 pfn=0x122233 order=0 migratetype=1 gfp_flags=GFP_HIGHUSER_MOVABLE|__GFP_COMP Cc: stable@vger.kernel.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Veronika Molnarova Cc: Suren Baghdasaryan Cc: Linus Torvalds Link: https://lore.kernel.org/20250116214438.749504792@goodmis.org Reported-by: Michael Petlan Closes: https://lore.kernel.org/all/87be5f7c-1a0-dad-daa0-54e342efaea7@redhat.com/ Fixes: 772dd0342727c ("mm: enumerate all gfp flags") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman

Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-09-21T14:29:05+00:00

Pull MM updates from Andrew Morton: "Along with the usual shower of singleton patches, notable patch series in this pull request are: - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds consistency to the APIs and behaviour of these two core allocation functions. This also simplifies/enables Rustification. - "Some cleanups for shmem" from Baolin Wang. No functional changes - mode code reuse, better function naming, logic simplifications. - "mm: some small page fault cleanups" from Josef Bacik. No functional changes - code cleanups only. - "Various memory tiering fixes" from Zi Yan. A small fix and a little cleanup. - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and simplifications and .text shrinkage. - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt. This is a feature, it adds new feilds to /proc/vmstat such as $ grep kstack /proc/vmstat kstack_1k 3 kstack_2k 188 kstack_4k 11391 kstack_8k 243 kstack_16k 0 which tells us that 11391 processes used 4k of stack while none at all used 16k. Useful for some system tuning things, but partivularly useful for "the dynamic kernel stack project". - "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory. - "mm: memcg: page counters optimizations" from Roman Gushchin. "3 independent small optimizations of page counters". - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David Hildenbrand. Improves PTE/PMD splitlock detection, makes powerpc/8xx work correctly by design rather than by accident. - "mm: remove arch_make_page_accessible()" from David Hildenbrand. Some folio conversions which make arch_make_page_accessible() unneeded. - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel. Cleans up and fixes our handling of the resetting of the cgroup/process peak-memory-use detector. - "Make core VMA operations internal and testable" from Lorenzo Stoakes. Rationalizaion and encapsulation of the VMA manipulation APIs. With a view to better enable testing of the VMA functions, even from a userspace-only harness. - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix issues in the zswap global shrinker, resulting in improved performance. - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill in some missing info in /proc/zoneinfo. - "mm: replace follow_page() by folio_walk" from David Hildenbrand. Code cleanups and rationalizations (conversion to folio_walk()) resulting in the removal of follow_page(). - "improving dynamic zswap shrinker protection scheme" from Nhat Pham. Some tuning to improve zswap's dynamic shrinker. Significant reductions in swapin and improvements in performance are shown. - "mm: Fix several issues with unaccepted memory" from Kirill Shutemov. Improvements to the new unaccepted memory feature, - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on DAX PUDs. This was missing, although nobody seems to have notied yet. - "Introduce a store type enum for the Maple tree" from Sidhartha Kumar. Cleanups and modest performance improvements for the maple tree library code. - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move more cgroup v1 remnants away from the v2 memcg code. - "memcg: initiate deprecation of v1 features" from Shakeel Butt. Adds various warnings telling users that memcg v1 features are deprecated. - "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li. Greatly improves the success rate of the mTHP swap allocation. - "mm: introduce numa_memblks" from Mike Rapoport. Moves various disparate per-arch implementations of numa_memblk code into generic code. - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly improves the performance of munmap() of swap-filled ptes. - "support large folio swap-out and swap-in for shmem" from Baolin Wang. With this series we no longer split shmem large folios into simgle-page folios when swapping out shmem. - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice performance improvements and code reductions for gigantic folios. - "support shmem mTHP collapse" from Baolin Wang. Adds support for khugepaged's collapsing of shmem mTHP folios. - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect() performance regression due to the addition of mseal(). - "Increase the number of bits available in page_type" from Matthew Wilcox. Increases the number of bits available in page_type! - "Simplify the page flags a little" from Matthew Wilcox. Many legacy page flags are now folio flags, so the page-based flags and their accessors/mutators can be removed. - "mm: store zero pages to be swapped out in a bitmap" from Usama Arif. An optimization which permits us to avoid writing/reading zero-filled zswap pages to backing store. - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race window which occurs when a MAP_FIXED operqtion is occurring during an unrelated vma tree walk. - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of the vma_merge() functionality, making ot cleaner, more testable and better tested. - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park. Minor fixups of DAMON selftests and kunit tests. - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang. Code cleanups and folio conversions. - "Shmem mTHP controls and stats improvements" from Ryan Roberts. Cleanups for shmem controls and stats. - "mm: count the number of anonymous THPs per size" from Barry Song. Expose additional anon THP stats to userspace for improved tuning. - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio conversions and removal of now-unused page-based APIs. - "replace per-quota region priorities histogram buffer with per-context one" from SeongJae Park. DAMON histogram rationalization. - "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae Park. DAMON documentation updates. - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve related doc and warn" from Jason Wang: fixes usage of page allocator __GFP_NOFAIL and GFP_ATOMIC flags. - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy. This was overprovisioning THPs in sparsely accessed memory areas. - "zram: introduce custom comp backends API" frm Sergey Senozhatsky. Add support for zram run-time compression algorithm tuning. - "mm: Care about shadow stack guard gap when getting an unmapped area" from Mark Brown. Fix up the various arch_get_unmapped_area() implementations to better respect guard areas. - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability of mem_cgroup_iter() and various code cleanups. - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge pfnmap support. - "resource: Fix region_intersects() vs add_memory_driver_managed()" from Huang Ying. Fix a bug in region_intersects() for systems with CXL memory. - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches a couple more code paths to correctly recover from the encountering of poisoned memry. - "mm: enable large folios swap-in support" from Barry Song. Support the swapin of mTHP memory into appropriately-sized folios, rather than into single-page folios" * tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits) zram: free secondary algorithms names uprobes: turn xol_area->pages[2] into xol_area->page uprobes: introduce the global struct vm_special_mapping xol_mapping Revert "uprobes: use vm_special_mapping close() functionality" mm: support large folios swap-in for sync io devices mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios mm: fix swap_read_folio_zeromap() for large folios with partial zeromap mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries set_memory: add __must_check to generic stubs mm/vma: return the exact errno in vms_gather_munmap_vmas() memcg: cleanup with !CONFIG_MEMCG_V1 mm/show_mem.c: report alloc tags in human readable units mm: support poison recovery from copy_present_page() mm: support poison recovery from do_cow_fault() resource, kunit: add test case for region_intersects() resource: make alloc_free_mem_region() works for iomem_resource mm: z3fold: deprecate CONFIG_Z3FOLD vfio/pci: implement huge_fault support mm/arm64: support large pfn mappings mm/x86: support large pfn mappings ...

mm: Define VM_DROPPABLE for powerpc/32

2024-09-13T15:28:36+00:00

Commit 9651fcedf7b9 ("mm: add MAP_DROPPABLE for designating always lazily freeable mappings") only adds VM_DROPPABLE for 64 bits architectures. In order to also use the getrandom vDSO implementation on powerpc/32, use VM_ARCH_1 for VM_DROPPABLE on powerpc/32. This is possible because VM_ARCH_1 is used for VM_SAO on powerpc and VM_SAO is only for powerpc/64. It is used in combination with PROT_SAO in some parts of code that are restricted to CONFIG_PPC64 through #ifdefs, it is therefore possible to define VM_SAO for CONFIG_PPC64 only. Signed-off-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Jason A. Donenfeld

x86: remove PG_uncached

2024-09-04T04:15:46+00:00

Convert x86 to use PG_arch_2 instead of PG_uncached and remove PG_uncached. Link: https://lkml.kernel.org/r/20240821193445.2294269-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

mm: rename PG_mappedtodisk to PG_owner_2

2024-09-04T04:15:45+00:00

This flag has similar constraints to PG_owner_priv_1 -- it is ignored by core code, and is entirely for the use of the code which allocated the folio. Since the pagecache does not use it, individual filesystems can use it. The bufferhead code does use it, so filesystems which use the buffer cache must not use it for another purpose. Link: https://lkml.kernel.org/r/20240821193445.2294269-10-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

printf: remove %pGt support

2024-09-04T04:15:42+00:00

Patch series "Increase the number of bits available in page_type". Kent wants more than 16 bits in page_type, so I resurrected this old patch and expanded it a bit. It's a bit more efficient than our current scheme (1 4-byte insn vs 3 insns of 13 bytes total) to test a single page type. This patch (of 4): An upcoming patch will convert page type from being a bitfield to a single byte, so we will not be able to use %pG to print the page type any more. The printing of the symbolic name will be restored in that patch. Link: https://lkml.kernel.org/r/20240821173914.2270383-1-willy@infradead.org Link: https://lkml.kernel.org/r/20240821173914.2270383-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Hildenbrand Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Kent Overstreet Signed-off-by: Andrew Morton

mm: remove PG_error

2024-09-02T03:26:05+00:00

The PG_error bit is now unused; delete it and free up a bit in page->flags. Link: https://lkml.kernel.org/r/20240807193528.1865100-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

mm: add MAP_DROPPABLE for designating always lazily freeable mappings

2024-07-19T18:22:12+00:00

The vDSO getrandom() implementation works with a buffer allocated with a new system call that has certain requirements: - It shouldn't be written to core dumps. * Easy: VM_DONTDUMP. - It should be zeroed on fork. * Easy: VM_WIPEONFORK. - It shouldn't be written to swap. * Uh-oh: mlock is rlimited. * Uh-oh: mlock isn't inherited by forks. - It shouldn't reserve actual memory, but it also shouldn't crash when page faulting in memory if none is available * Uh-oh: VM_NORESERVE means segfaults. It turns out that the vDSO getrandom() function has three really nice characteristics that we can exploit to solve this problem: 1) Due to being wiped during fork(), the vDSO code is already robust to having the contents of the pages it reads zeroed out midway through the function's execution. 2) In the absolute worst case of whatever contingency we're coding for, we have the option to fallback to the getrandom() syscall, and everything is fine. 3) The buffers the function uses are only ever useful for a maximum of 60 seconds -- a sort of cache, rather than a long term allocation. These characteristics mean that we can introduce VM_DROPPABLE, which has the following semantics: a) It never is written out to swap. b) Under memory pressure, mm can just drop the pages (so that they're zero when read back again). c) It is inherited by fork. d) It doesn't count against the mlock budget, since nothing is locked. e) If there's not enough memory to service a page fault, it's not fatal, and no signal is sent. This way, allocations used by vDSO getrandom() can use: VM_DROPPABLE | VM_DONTDUMP | VM_WIPEONFORK | VM_NORESERVE And there will be no problem with OOMing, crashing on overcommitment, using memory when not in use, not wiping on fork(), coredumps, or writing out to swap. In order to let vDSO getrandom() use this, expose these via mmap(2) as MAP_DROPPABLE. Note that this involves removing the MADV_FREE special case from sort_folio(), which according to Yu Zhao is unnecessary and will simply result in an extra call to shrink_folio_list() in the worst case. The chunk removed reenables the swapbacked flag, which we don't want for VM_DROPPABLE, and we can't conditionalize it here because there isn't a vma reference available. Finally, the provided self test ensures that this is working as desired. Cc: linux-mm@kvack.org Acked-by: David Hildenbrand Signed-off-by: Jason A. Donenfeld

mm: free up PG_slab

2024-04-26T03:56:00+00:00

Reclaim the Slab page flag by using a spare bit in PageType. We are perennially short of page flags for various purposes, and now that the original SLAB allocator has been retired, SLUB does not use the mapcount/page_type field. This lets us remove a number of special cases for ignoring mapcount on Slab pages. [willy@infradead.org: update vmcoreinfo] Link: https://lkml.kernel.org/r/ZgGV-O8WYQ_83kxp@casper.infradead.org Link: https://lkml.kernel.org/r/20240321142448.1645400-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: David Hildenbrand Cc: Miaohe Lin Cc: Muchun Song Cc: Oscar Salvador Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: turn folio_test_hugetlb into a PageType

2024-04-25T02:34:26+00:00

The current folio_test_hugetlb() can be fooled by a concurrent folio split into returning true for a folio which has never belonged to hugetlbfs. This can't happen if the caller holds a refcount on it, but we have a few places (memory-failure, compaction, procfs) which do not and should not take a speculative reference. Since hugetlb pages do not use individual page mapcounts (they are always fully mapped and use the entire_mapcount field to record the number of mappings), the PageType field is available now that page_mapcount() ignores the value in this field. In compaction and with CONFIG_DEBUG_VM enabled, the current implementation can result in an oops, as reported by Luis. This happens since 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR") effectively added some VM_BUG_ON() checks in the PageHuge() testing path. [willy@infradead.org: update vmcoreinfo] Link: https://lkml.kernel.org/r/ZgGZUvsdhaT1Va-T@casper.infradead.org Link: https://lkml.kernel.org/r/20240321142448.1645400-6-willy@infradead.org Fixes: 9c5ccf2db04b ("mm: remove HUGETLB_PAGE_DTOR") Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: David Hildenbrand Acked-by: Vlastimil Babka Reported-by: Luis Chamberlain Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218227 Cc: Miaohe Lin Cc: Muchun Song Cc: Oscar Salvador Cc: Signed-off-by: Andrew Morton