- 03 Feb, 2023 40 commits
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Vishal Moola (Oracle) authored
Convert function to use folios throughout. This is in preparation for the removal of find_get_pages_range_tag(). This change removes 8 calls to compound_head(), and the function now supports large folios. Link: https://lkml.kernel.org/r/20230104211448.4804-5-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcow (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
Convert function to use folios. This is in preparation for the removal of find_get_pages_range_tag(). This change removes 2 calls to compound_head(). Link: https://lkml.kernel.org/r/20230104211448.4804-4-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcow (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
This is the equivalent of find_get_pages_range_tag(), except for folios instead of pages. One noteable difference is filemap_get_folios_tag() does not take in a maximum pages argument. It instead tries to fill a folio batch and stops either once full (15 folios) or reaching the end of the search range. The new function supports large folios, the initial function did not since all callers don't use large folios. Link: https://lkml.kernel.org/r/20230104211448.4804-3-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcow (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
Patch series "Convert to filemap_get_folios_tag()", v5. This patch series replaces find_get_pages_range_tag() with filemap_get_folios_tag(). This also allows the removal of multiple calls to compound_head() throughout. It also makes a good chunk of the straightforward conversions to folios, and takes the opportunity to introduce a function that grabs a folio from the pagecache. This patch (of 23): Add function filemap_grab_folio() to grab a folio from the page cache. This function is meant to serve as a folio replacement for grab_cache_page, and is used to facilitate the removal of find_get_pages_range_tag(). Link: https://lkml.kernel.org/r/20230104211448.4804-1-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20230104211448.4804-2-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Stevens authored
Pass vm_flags as a parameter to shmem_is_huge, rather than reading the flags from the vm_area_struct in question. This allows the updated flags from hugepage_madvise to be passed to the check, which is necessary because madvise does not update the vm_area_struct's flags until after hugepage_madvise returns. This fixes an issue when shmem_enabled=madvise, where MADV_HUGEPAGE on shmem was not able to register the mm_struct with khugepaged. Prior to cd89fb06, the mm_struct was registered by MADV_HUGEPAGE regardless of the value of shmem_enabled (which was only checked when scanning vmas). Link: https://lkml.kernel.org/r/20230113023011.1784015-1-stevensd@google.com Fixes: cd89fb06 ("mm,thp,shmem: make khugepaged obey tmpfs mount flags") Signed-off-by: David Stevens <stevensd@chromium.org> Cc: David Stevens <stevensd@chromium.org> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@surriel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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NeilBrown authored
__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.netSigned-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mel Gorman authored
GFP_ATOMIC allocations get flagged ALLOC_HARDER which is a vague description. In preparation for the removal of GFP_ATOMIC redefine __GFP_ATOMIC to simply mean non-blocking and renaming ALLOC_HARDER to ALLOC_NON_BLOCK accordingly. __GFP_HIGH is required for access to reserves but non-blocking is granted more access. For example, GFP_NOWAIT is non-blocking but has no special access to reserves. A __GFP_NOFAIL blocking allocation is granted access similar to __GFP_HIGH if the only alternative is an OOM kill. Link: https://lkml.kernel.org/r/20230113111217.14134-6-mgorman@techsingularity.netSigned-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: NeilBrown <neilb@suse.de> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mel Gorman authored
As there are more ALLOC_ flags that affect reserves, define what flags affect reserves and clarify the effect of each flag. Link: https://lkml.kernel.org/r/20230113111217.14134-5-mgorman@techsingularity.netSigned-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: NeilBrown <neilb@suse.de> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mel Gorman authored
A high-order ALLOC_HARDER allocation is assumed to be atomic. While that is accurate, it changes later in the series. In preparation, explicitly record high-order atomic allocations in gfp_to_alloc_flags(). Link: https://lkml.kernel.org/r/20230113111217.14134-4-mgorman@techsingularity.netSigned-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: NeilBrown <neilb@suse.de> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mel Gorman authored
RT tasks are allowed to dip below the min reserve but ALLOC_HARDER is typically combined with ALLOC_MIN_RESERVE so RT tasks are a little unusual. While there is some justification for allowing RT tasks access to memory reserves, there is a strong chance that a RT task that is also under memory pressure is at risk of missing deadlines anyway. Relax how much reserves an RT task can access by treating it the same as __GFP_HIGH allocations. Note that in a future kernel release that the RT special casing will be removed. Hard realtime tasks should be locking down resources in advance and ensuring enough memory is available. Even a soft-realtime task like audio or video live decoding which cannot jitter should be allocating both memory and any disk space required up-front before the recording starts instead of relying on reserves. At best, reserve access will only delay the problem by a very short interval. Link: https://lkml.kernel.org/r/20230113111217.14134-3-mgorman@techsingularity.netSigned-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: NeilBrown <neilb@suse.de> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Mel Gorman authored
Patch series "Discard __GFP_ATOMIC", v3. Neil's patch has been residing in mm-unstable as commit 2fafb4fe8f7a ("mm: discard __GFP_ATOMIC") for a long time and recently brought up again. Most recently, I was worried that __GFP_HIGH allocations could use high-order atomic reserves which is unintentional but there was no response so lets revisit -- this series reworks how min reserves are used, protects highorder reserves and then finishes with Neil's patch with very minor modifications so it fits on top. There was a review discussion on renaming __GFP_DIRECT_RECLAIM to __GFP_ALLOW_BLOCKING but I didn't think it was that big an issue and is orthogonal to the removal of __GFP_ATOMIC. There were some concerns about how the gfp flags affect the min reserves but it never reached a solid conclusion so I made my own attempt. The series tries to iron out some of the details on how reserves are used. ALLOC_HIGH becomes ALLOC_MIN_RESERVE and ALLOC_HARDER becomes ALLOC_NON_BLOCK and documents how the reserves are affected. For example, ALLOC_NON_BLOCK (no direct reclaim) on its own allows 25% of the min reserve. ALLOC_MIN_RESERVE (__GFP_HIGH) allows 50% and both combined allows deeper access again. ALLOC_OOM allows access to 75%. High-order atomic allocations are explicitly handled with the caveat that no __GFP_ATOMIC flag means that any high-order allocation that specifies GFP_HIGH and cannot enter direct reclaim will be treated as if it was GFP_ATOMIC. This patch (of 6): __GFP_HIGH aliases to ALLOC_HIGH but the name does not really hint what it means. As ALLOC_HIGH is internal to the allocator, rename it to ALLOC_MIN_RESERVE to document that the min reserves can be depleted. Link: https://lkml.kernel.org/r/20230113111217.14134-1-mgorman@techsingularity.net Link: https://lkml.kernel.org/r/20230113111217.14134-2-mgorman@techsingularity.netSigned-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: NeilBrown <neilb@suse.de> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Pasha Tatashin authored
There is 8 byte page_ext->flags field allocated per page whenever CONFIG_PAGE_EXTENSION is enabled. However, not every user of page_ext uses flags. Therefore, check whether flags is needed at least by one user and if so allocate space for it. For example when page_table_check is enabled, on a machine with 128G of memory before the fix: [ 2.244288] allocated 536870912 bytes of page_ext after the fix: [ 2.160154] allocated 268435456 bytes of page_ext Also, add a kernel-doc comment before page_ext_operations that describes the fields, and remove check if need() is set, as that is now a required field. [pasha.tatashin@soleen.com: address comments from Mike Rapoport] Link: https://lkml.kernel.org/r/20230117202103.1412449-1-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20230113154253.92480-1-pasha.tatashin@soleen.comSigned-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Charan Teja Kalla <quic_charante@quicinc.com> Cc: Li Zhe <lizhe.67@bytedance.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
__HAVE_ARCH_PTE_SWP_EXCLUSIVE is now supported by all architectures that support swp PTEs, so let's drop it. Link: https://lkml.kernel.org/r/20230113171026.582290-27-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 1. This bit should be safe to use for our usecase. Most importantly, we can still distinguish swap PTEs from PAGE_NONE PTEs (see pte_present()) and don't use one of the two reserved attribute masks (1101 and 1111). Attribute mask 1100 and 1110 now identify swap PTEs. While at it, remove SWP_TYPE_BITS (not really helpful as it's not used in the actual swap macros) and mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-26-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE just like we already do on x86-64. After deciphering the PTE layout it becomes clear that there are still unused bits for 2-level and 3-level page tables that we should be able to use. Reusing a bit avoids stealing one bit from the swap offset. While at it, mask the type in __swp_entry(); use some helper definitions to make the macros easier to grasp. Link: https://lkml.kernel.org/r/20230113171026.582290-25-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 10, which is yet unused for swap PTEs. The pte_mkuptodate() is a bit weird in __pte_to_swp_entry() for a swap PTE ... but it only messes with bit 1 and 2 and there is a comment in set_pte(), so leave these bits alone. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-24-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit was effectively unused. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-23-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by reusing the SRMMU_DIRTY bit as that seems to be safe to reuse inside a swap PTE. This avoids having to steal one bit from the swap offset. While at it, relocate the swap PTE layout documentation and use the same style now used for most other archs. Note that the old documentation was wrong: we use 20 bit for the offset and the reserved bits were 8 instead of 7 bits in the ascii art. Link: https://lkml.kernel.org/r/20230113171026.582290-22-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 6 in the PTE, reducing the swap type in the !CONFIG_X2TLB case to 5 bits. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. Interrestingly, the swap type in the !CONFIG_X2TLB case could currently overlap with the _PAGE_PRESENT bit, because there is a sneaky shift by 1 in __pte_to_swp_entry() and __swp_entry_to_pte(). Bit 0-7 in the architecture specific swap PTE would get shifted to bit 1-8 in the PTE. As generic MM uses 5 bits only, this didn't matter so far. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-21-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file: on 32bit to 16 GiB (was 32 GiB). Note that this bit does not conflict with swap PMDs and could also be used in swap PMD context later. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-20-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit and 64bit. On 64bit, let's use MSB 56 (LSB 7), located right next to the page type. On 32bit, let's use LSB 2 to avoid stealing one bit from the swap offset. There seems to be no real reason why these bits cannot be used for swap PTEs. The important part is that _PAGE_PRESENT and _PAGE_HASHPTE remain 0. While at it, mask the type in __swp_entry() and remove _PAGE_BIT_SWAP_TYPE from pte-e500.h: while it was used in 64bit code it was ignored in 32bit code. Link: https://lkml.kernel.org/r/20230113171026.582290-19-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
We already implemented support for 64bit book3s in commit bff9beaa ("powerpc/pgtable: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE for book3s") Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE also in 32bit by reusing yet unused LSB 2 / MSB 29. There seems to be no real reason why that bit cannot be used, and reusing it avoids having to steal one bit from the swap offset. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-18-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using the yet-unused _PAGE_ACCESSED location in the swap PTE. Looking at pte_present() and pte_none() checks, there seems to be no actual reason why we cannot use it: we only have to make sure we're not using _PAGE_PRESENT. Reusing this bit avoids having to steal one bit from the swap offset. Link: https://lkml.kernel.org/r/20230113171026.582290-17-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-16-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Stafford Horne <shorne@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using the yet-unused bit 31. Link: https://lkml.kernel.org/r/20230113171026.582290-15-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
nios2 disables swap for a good reason: it doesn't even provide sufficient type bits as required by core MM. However, swap entries are nowadays also used for other purposes (migration entries, PTE markers, HWPoison, ...), and accidential use could be problematic. Let's properly use 5 bits for the swap type and document the layout. Bits 26--31 should get ignored by hardware completely, so they can be used. Link: https://lkml.kernel.org/r/20230113171026.582290-14-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE. On 64bit, steal one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. On 32bit we're able to locate unused bits. As the PTE layout for 32 bit is very confusing, document it a bit better. While at it, mask the type in __swp_entry()/mk_swap_pte(). Link: https://lkml.kernel.org/r/20230113171026.582290-13-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. The shift by 2 when converting between PTE and arch-specific swap entry makes the swap PTE layout a little bit harder to decipher. While at it, drop the comment from paulus---copy-and-paste leftover from powerpc where we actually have _PAGE_HASHPTE---and mask the type in __swp_entry_to_pte() as well. Link: https://lkml.kernel.org/r/20230113171026.582290-12-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Michal Simek <monstr@monstr.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, make sure for sun3 that the valid bit never gets set by properly masking it off and mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-11-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
The definitions are not required, let's remove them. Link: https://lkml.kernel.org/r/20230113171026.582290-10-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, also mask the type in mk_swap_pte(). Note that this bit does not conflict with swap PMDs and could also be used in swap PMD context later. Link: https://lkml.kernel.org/r/20230113171026.582290-9-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, also mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-8-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 16 GiB (was 32 GiB). While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-7-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Brian Cain <bcain@quicinc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 16 GiB (was 32 GiB). We might actually be able to reuse one of the other software bits (_PAGE_READ / PAGE_WRITE) instead, because we only have to keep pte_present(), pte_none() and HW happy. For now, let's keep it simple because there might be something non-obvious. Link: https://lkml.kernel.org/r/20230113171026.582290-6-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Guo Ren <guoren@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 64 GiB (was 128 GiB). While at it drop the PTE_TYPE_FAULT from __swp_entry_to_pte() which is defined to be 0 and is rather confusing because we should be dealing with "Linux PTEs" not "hardware PTEs". Also, properly mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-5-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 5, which is yet unused. The only important parts seems to be to not use _PAGE_PRESENT (bit 9). Link: https://lkml.kernel.org/r/20230113171026.582290-4-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, mask the type in mk_swap_pte() as well. Link: https://lkml.kernel.org/r/20230113171026.582290-3-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Patch series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". This is the follow-up on [1]: [PATCH v2 0/8] mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages After we implemented __HAVE_ARCH_PTE_SWP_EXCLUSIVE on most prominent enterprise architectures, implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all remaining architectures that support swap PTEs. This makes sure that exclusive anonymous pages will stay exclusive, even after they were swapped out -- for example, making GUP R/W FOLL_GET of anonymous pages reliable. Details can be found in [1]. This primarily fixes remaining known O_DIRECT memory corruptions that can happen on concurrent swapout, whereby we can lose DMA reads to a page (modifying the user page by writing to it). To verify, there are two test cases (requiring swap space, obviously): (1) The O_DIRECT+swapout test case [2] from Andrea. This test case tries triggering a race condition. (2) My vmsplice() test case [3] that tries to detect if the exclusive marker was lost during swapout, not relying on a race condition. For example, on 32bit x86 (with and without PAE), my test case fails without these patches: $ ./test_swp_exclusive FAIL: page was replaced during COW But succeeds with these patches: $ ./test_swp_exclusive PASS: page was not replaced during COW Why implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE for all architectures, even the ones where swap support might be in a questionable state? This is the first step towards removing "readable_exclusive" migration entries, and instead using pte_swp_exclusive() also with (readable) migration entries instead (as suggested by Peter). The only missing piece for that is supporting pmd_swp_exclusive() on relevant architectures with THP migration support. As all relevant architectures now implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE,, we can drop __HAVE_ARCH_PTE_SWP_EXCLUSIVE in the last patch. I tried cross-compiling all relevant setups and tested on x86 and sparc64 so far. CCing arch maintainers only on this cover letter and on the respective patch(es). [1] https://lkml.kernel.org/r/20220329164329.208407-1-david@redhat.com [2] https://gitlab.com/aarcange/kernel-testcases-for-v5.11/-/blob/main/page_count_do_wp_page-swap.c [3] https://gitlab.com/davidhildenbrand/scratchspace/-/blob/main/test_swp_exclusive.c This patch (of 26): We want to implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures. Let's extend our sanity checks, especially testing that our PTE bit does not affect: * is_swap_pte() -> pte_present() and pte_none() * the swap entry + type * pte_swp_soft_dirty() Especially, the pfn_pte() is dodgy when the swap PTE layout differs heavily from ordinary PTEs. Let's properly construct a swap PTE from swap type+offset. [david@redhat.com: fix build] Link: https://lkml.kernel.org/r/6aaad548-cf48-77fa-9d6c-db83d724b2eb@redhat.com Link: https://lkml.kernel.org/r/20230113171026.582290-1-david@redhat.com Link: https://lkml.kernel.org/r/20230113171026.582290-2-david@redhat.comSigned-off-by: David Hildenbrand <david@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: <aou@eecs.berkeley.edu> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Chris Zankel <chris@zankel.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: H. Peter Anvin (Intel) <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Nadav Amit <namit@vmware.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Xu <peterx@redhat.com> Cc: Richard Henderson <richard.henderson@linaro.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuerui Wang <kernel@xen0n.name> Cc: Yang Shi <shy828301@gmail.com> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
Converts release_pte_pages() to use folios instead of pages. Link: https://lkml.kernel.org/r/20230114001556.43795-2-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Vishal Moola (Oracle) authored
release_pte_page() is converted to be a wrapper for release_pte_folio() to help facilitate the khugepaged conversion to folios. This replaces 3 calls to compound_head() with 1, and saves 85 bytes of kernel text. Link: https://lkml.kernel.org/r/20230114001556.43795-1-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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