kernel/linux.git/include/trace/events/mmflags.h, branch v6.6.131

mm: turn folio_test_hugetlb into a PageType

2024-05-02T14:32:47+00:00

commit d99e3140a4d33e26066183ff727d8f02f56bec64 upstream. 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 Signed-off-by: Greg Kroah-Hartman

mm: compaction: remove compaction result helpers

2023-06-09T23:25:36+00:00

Patch series "mm: compaction: cleanups & simplifications". These compaction cleanups are split out from the huge page allocator series[1], as requested by reviewer feedback. [1] https://lore.kernel.org/linux-mm/20230418191313.268131-1-hannes@cmpxchg.org/ This patch (of 5): The compaction result helpers encode quirks that are specific to the allocator's retry logic. E.g. COMPACT_SUCCESS and COMPACT_COMPLETE actually represent failures that should be retried upon, and so on. I frequently found myself pulling up the helper implementation in order to understand and work on the retry logic. They're not quite clean abstractions; rather they split the retry logic into two locations. Remove the helpers and inline the checks. Then comment on the result interpretations directly where the decision making happens. Link: https://lkml.kernel.org/r/20230519123959.77335-1-hannes@cmpxchg.org Link: https://lkml.kernel.org/r/20230519123959.77335-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Vlastimil Babka Cc: Mel Gorman Cc: Michal Hocko Signed-off-by: Andrew Morton

kasan: remove PG_skip_kasan_poison flag

2023-03-28T23:20:16+00:00

Code inspection reveals that PG_skip_kasan_poison is redundant with kasantag, because the former is intended to be set iff the latter is the match-all tag. It can also be observed that it's basically pointless to poison pages which have kasantag=0, because any pages with this tag would have been pointed to by pointers with match-all tags, so poisoning the pages would have little to no effect in terms of bug detection. Therefore, change the condition in should_skip_kasan_poison() to check kasantag instead, and remove PG_skip_kasan_poison and associated flags. Link: https://lkml.kernel.org/r/20230310042914.3805818-3-pcc@google.com Link: https://linux-review.googlesource.com/id/I57f825f2eaeaf7e8389d6cf4597c8a5821359838 Signed-off-by: Peter Collingbourne Reviewed-by: Andrey Konovalov Cc: Andrey Ryabinin Cc: Catalin Marinas Cc: Evgenii Stepanov Cc: Vincenzo Frascino Cc: Will Deacon Signed-off-by: Andrew Morton

mm, printk: introduce new format %pGt for page_type

2023-03-28T23:20:09+00:00

%pGp format is used to display 'flags' field of a struct page. However, some page flags (i.e. PG_buddy, see page-flags.h for more details) are stored in page_type field. To display human-readable output of page_type, introduce %pGt format. It is important to note the meaning of bits are different in page_type. if page_type is 0xffffffff, no flags are set. Setting PG_buddy (0x00000080) flag results in a page_type of 0xffffff7f. Clearing a bit actually means setting a flag. Bits in page_type are inverted when displaying type names. Only values for which page_type_has_type() returns true are considered as page_type, to avoid confusion with mapcount values. if it returns false, only raw values are displayed and not page type names. Link: https://lkml.kernel.org/r/20230130042514.2418-3-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Petr Mladek [vsprintf part] Cc: Andy Shevchenko Cc: David Hildenbrand Cc: Joe Perches Cc: John Ogness Cc: Matthew Wilcox Cc: Sergey Senozhatsky Cc: Steven Rostedt (Google) Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mmflags.h: use less error prone method to define pageflag_names

2023-03-28T23:20:08+00:00

Patch series "mm, printk: introduce new format for page_type", v4. This series moves PG_slab page flag to page_type, freeing one bit in page->flags and introduces %pGt format that prints human-readable page_type like %pGp for printing page flags. See changelog of patch 2 for more implementation details. Thanks everyone that gave valuable comments. This patch (of 3): Use helper macro to decrease chances of typo when defining pageflag_names. Link: https://lkml.kernel.org/r/20230130042514.2418-1-42.hyeyoo@gmail.com Link: https://lore.kernel.org/lkml/Y6AycLbpjVzXM5I9@smile.fi.intel.com Link: https://lkml.kernel.org/r/20230130042514.2418-2-42.hyeyoo@gmail.com Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Suggested-by: Andy Shevchenko Reviewed-by: Andy Shevchenko Cc: David Hildenbrand Cc: Joe Perches Cc: Matthew Wilcox Cc: Petr Mladek Cc: Steven Rostedt (Google) Cc: Vlastimil Babka Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: John Ogness Signed-off-by: Andrew Morton

mm: discard __GFP_ATOMIC

2023-02-03T06:33:13+00:00

__GFP_ATOMIC serves little purpose. Its main effect is to set ALLOC_HARDER which adds a few little boosts to increase the chance of an allocation succeeding, one of which is to lower the water-mark at which it will succeed. It is *always* paired with __GFP_HIGH which sets ALLOC_HIGH which also adjusts this watermark. It is probable that other users of __GFP_HIGH should benefit from the other little bonuses that __GFP_ATOMIC gets. __GFP_ATOMIC also gives a warning if used with __GFP_DIRECT_RECLAIM. There is little point to this. We already get a might_sleep() warning if __GFP_DIRECT_RECLAIM is set. __GFP_ATOMIC allows the "watermark_boost" to be side-stepped. It is probable that testing ALLOC_HARDER is a better fit here. __GFP_ATOMIC is used by tegra-smmu.c to check if the allocation might sleep. This should test __GFP_DIRECT_RECLAIM instead. This patch: - removes __GFP_ATOMIC - allows __GFP_HIGH allocations to ignore watermark boosting as well as GFP_ATOMIC requests. - makes other adjustments as suggested by the above. The net result is not change to GFP_ATOMIC allocations. Other allocations that use __GFP_HIGH will benefit from a few different extra privileges. This affects: xen, dm, md, ntfs3 the vermillion frame buffer hibernation ksm swap all of which likely produce more benefit than cost if these selected allocation are more likely to succeed quickly. [mgorman: Minor adjustments to rework on top of a series] Link: https://lkml.kernel.org/r/163712397076.13692.4727608274002939094@noble.neil.brown.name Link: https://lkml.kernel.org/r/20230113111217.14134-7-mgorman@techsingularity.net Signed-off-by: NeilBrown Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Acked-by: Michal Hocko Cc: Matthew Wilcox Cc: Thierry Reding Signed-off-by: Andrew Morton

mm: Add PG_arch_3 page flag

2022-11-29T09:26:07+00:00

As with PG_arch_2, this flag is only allowed on 64-bit architectures due to the shortage of bits available. It will be used by the arm64 MTE code in subsequent patches. Signed-off-by: Peter Collingbourne Cc: Will Deacon Cc: Marc Zyngier Cc: Steven Price [catalin.marinas@arm.com: added flag preserving in __split_huge_page_tail()] Signed-off-by: Catalin Marinas Reviewed-by: Steven Price Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221104011041.290951-5-pcc@google.com

mm: Do not enable PG_arch_2 for all 64-bit architectures

2022-11-29T09:26:06+00:00

Commit 4beba9486abd ("mm: Add PG_arch_2 page flag") introduced a new page flag for all 64-bit architectures. However, even if an architecture is 64-bit, it may still have limited spare bits in the 'flags' member of 'struct page'. This may happen if an architecture enables SPARSEMEM without SPARSEMEM_VMEMMAP as is the case with the newly added loongarch. This architecture port needs 19 more bits for the sparsemem section information and, while it is currently fine with PG_arch_2, adding any more PG_arch_* flags will trigger build-time warnings. Add a new CONFIG_ARCH_USES_PG_ARCH_X option which can be selected by architectures that need more PG_arch_* flags beyond PG_arch_1. Select it on arm64. Signed-off-by: Catalin Marinas [pcc@google.com: fix build with CONFIG_ARM64_MTE disabled] Signed-off-by: Peter Collingbourne Reported-by: kernel test robot Cc: Andrew Morton Cc: Steven Price Reviewed-by: Steven Price Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20221104011041.290951-2-pcc@google.com

include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"

2022-05-25T17:47:47+00:00

Redefines __def_gfpflag_names array according to akpm@, willy@ and Joe Perches recommendations. Link: https://lkml.kernel.org/r/6f811e19-41c6-f3e8-fca6-23a19a62e313@openvz.org Fixes: fe573327ffb1 ("tracing: incorrect gfp_t conversion") Signed-off-by: Vasily Averin Cc: Matthew Wilcox Cc: Joe Perches Cc: Steven Rostedt Signed-off-by: Andrew Morton

tracing: incorrect gfp_t conversion

2022-05-13T14:20:18+00:00

Fixes the following sparse warnings: include/trace/events/*: sparse: cast to restricted gfp_t include/trace/events/*: sparse: restricted gfp_t degrades to integer gfp_t type is bitwise and requires __force attributes for any casts. Link: https://lkml.kernel.org/r/331d88fe-f4f7-657c-02a2-d977f15fbff6@openvz.org Signed-off-by: Vasily Averin Cc: Steven Rostedt Cc: Ingo Molnar Signed-off-by: Andrew Morton