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1368687 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Lorenzo Stoakes
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bfbe71109f |
mm: update core kernel code to use vm_flags_t consistently
The core kernel code is currently very inconsistent in its use of vm_flags_t vs. unsigned long. This prevents us from changing the type of vm_flags_t in the future and is simply not correct, so correct this. While this results in rather a lot of churn, it is a critical pre-requisite for a future planned change to VMA flag type. Additionally, update VMA userland tests to account for the changes. To make review easier and to break things into smaller parts, driver and architecture-specific changes is left for a subsequent commit. The code has been adjusted to cascade the changes across all calling code as far as is needed. We will adjust architecture-specific and driver code in a subsequent patch. Overall, this patch does not introduce any functional change. Link: https://lkml.kernel.org/r/d1588e7bb96d1ea3fe7b9df2c699d5b4592d901d.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Kees Cook <kees@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Jan Kara <jack@suse.cz> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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78ddaa358e |
mm: change vm_get_page_prot() to accept vm_flags_t argument
Patch series "use vm_flags_t consistently". The VMA flags field vma->vm_flags is of type vm_flags_t. Right now this is exactly equivalent to unsigned long, but it should not be assumed to be. Much code that references vma->vm_flags already correctly uses vm_flags_t, but a fairly large chunk of code simply uses unsigned long and assumes that the two are equivalent. This series corrects that and has us use vm_flags_t consistently. This series is motivated by the desire to, in a future series, adjust vm_flags_t to be a u64 regardless of whether the kernel is 32-bit or 64-bit in order to deal with the VMA flag exhaustion issue and avoid all the various problems that arise from it (being unable to use certain features in 32-bit, being unable to add new flags except for 64-bit, etc.) This is therefore a critical first step towards that goal. At any rate, using the correct type is of value regardless. We additionally take the opportunity to refer to VMA flags as vm_flags where possible to make clear what we're referring to. Overall, this series does not introduce any functional change. This patch (of 3): We abstract the type of the VMA flags to vm_flags_t, however in may places it is simply assumed this is unsigned long, which is simply incorrect. At the moment this is simply an incongruity, however in future we plan to change this type and therefore this change is a critical requirement for doing so. Overall, this patch does not introduce any functional change. [lorenzo.stoakes@oracle.com: add missing vm_get_page_prot() instance, remove include] Link: https://lkml.kernel.org/r/552f88e1-2df8-4e95-92b8-812f7c8db829@lucifer.local Link: https://lkml.kernel.org/r/cover.1750274467.git.lorenzo.stoakes@oracle.com Link: https://lkml.kernel.org/r/a12769720a2743f235643b158c4f4f0a9911daf0.1750274467.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Christian Brauner <brauner@kernel.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Jann Horn <jannh@google.com> Cc: Kees Cook <kees@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jarkko Sakkinen <jarkko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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SeongJae Park
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e1b1fe4557 |
Revert "mm: make alloc_demote_folio externally invokable for migration"
This reverts commit |
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SeongJae Park
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29ea04095b |
Revert "mm: rename alloc_demote_folio to alloc_migrate_folio"
This reverts commit |
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SeongJae Park
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b435415eed |
mm/damon/paddr: use alloc_migartion_target() with no migration fallback nodemask
Patch series "mm/damon: use alloc_migrate_target() for
DAMOS_MIGRATE_{HOT,COLD}".
DAMOS_MIGRATE_{HOT,COLD} implementation resembles that for demotion, and
hence the behavior is also similar to that. But, since those are not only
for demotion but general migrations, it would be better to match with that
for move_pages() system call. Make the implementation and the behavior
more similar to move_pages() by not setting migration fallback nodes, and
using alloc_migration_target() instead of alloc_migrate_folio().
alloc_migrate_folio() was renamed from alloc_demote_folio() and been
non-static function, to let DAMOS_MIGRATE_{HOT,COLD} call it. As
alloc_migration_target() is called instead, the renaming and de-static
changes are no more required but could only make future code readers be
confused. Revert the changes, too.
This patch (of 3):
DAMOS_MIGRATE_{HOT,COLD} implementation resembles that for
demote_folio_list(). Because those are not only for demotion but general
folio migrations, it makes more sense to behave similarly to move_pages()
system call. Make the behavior more similar to move_pages(), by using
alloc_migration_target() instead of alloc_migrate_folio(), without
fallback nodemask.
Link: https://lkml.kernel.org/r/20250616172346.67659-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Honggyu Kim <honggyu.kim@sk.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Liam R. Howlett
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ec3681e873 |
tools/testing/radix-tree: test maple tree chaining mas_preallocate() calls
Testing calling multiple mas_preallocate() calls in a row after adjusting the maple state. Ensures new calls to mas_preallocate() will change the number of allocated nodes. Link: https://lkml.kernel.org/r/20250616184521.3382795-4-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Hailong Liu <hailong.liu@oppo.com> Cc: "Liam R. Howlett" <howlett@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Liam R. Howlett
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f687fd5af8 |
testing/radix-tree/maple: increase readers and reduce delay for faster machines
Faster machines may not see the initial or updated value in the race condition. Reduce the delay so that faster machines are less likely to fail testing of the race conditions. Link: https://lkml.kernel.org/r/20250616184521.3382795-2-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <howlett@gmail.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Hailong Liu <hailong.liu@oppo.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peng Zhang <zhangpeng.00@bytedance.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Baolin Wang
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fa493f50df |
mm: huge_memory: fix the check for allowed huge orders in shmem
Shmem already supports mTHP, and shmem_allowable_huge_orders() will return
the huge orders allowed by shmem. However, there is no check against the
'orders' parameter passed by __thp_vma_allowable_orders(), which can lead
to incorrect check results for __thp_vma_allowable_orders().
For example, when a user wants to check if shmem supports PMD-sized THP by
thp_vma_allowable_order(), if shmem only enables 64K mTHP, the current
logic would cause thp_vma_allowable_order() to return true, implying that
shmem allows PMD-sized THP allocation, which it actually does not.
I don't think this will cause a significant impact on users, and this will
only have some impact on the shmem THP collapse. That is to say, even
though the shmem sysfs setting does not enable the PMD-sized THP, the
thp_vma_allowable_order() still indicates that shmem allows PMD-sized
collapse, meaning it might successfully collapse into THP, or it might not
(for example, thp_vma_suitable_order() check failed in the collapse
process). However, this still does not align with the shmem sysfs
configuration, fix it.
Link: https://lkml.kernel.org/r/529affb3220153d0d5a542960b535cdfc33f51d7.1749804835.git.baolin.wang@linux.alibaba.com
Fixes:
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Mark Brown
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3e49aa8e65 |
selftest/mm: skip if fallocate() is unsupported in gup_longterm
Currently gup_longterm assumes that filesystems support fallocate() and uses that to allocate space in files, however this is an optional feature and is in particular not implemented by NFSv3 which is commonly used in CI systems leading to spurious failures. Check for lack of support and report a skip instead for that case. Link: https://lkml.kernel.org/r/20250613-selftest-mm-gup-longterm-fallocate-nfs-v1-1-758a104c175f@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
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4535cb331c |
mm/vma: use vmg->target to specify target VMA for new VMA merge
In commit
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Matthew Wilcox (Oracle)
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9e82db9c0c |
highmem: remove a use of folio->page
Call folio_address() instead of page_address(). Link: https://lkml.kernel.org/r/20250613194825.3175276-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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32925ee63b |
secretmem: remove uses of struct page
Use filemap_lock_folio() instead of find_lock_page() to retrieve a folio from the page cache. [lorenzo.stoakes@oracle.com: fix check of filemap_lock_folio() return value] Link: https://lkml.kernel.org/r/fdbca1d0-01a3-4653-85ed-cf257bb848be@lucifer.local Link: https://lkml.kernel.org/r/20250613194744.3175157-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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David Hildenbrand
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02825c0925 |
mm/huge_memory: don't mark refcounted folios special in vmf_insert_folio_pud()
Marking PUDs that map a "normal" refcounted folios as special is against
our rules documented for vm_normal_page(). normal (refcounted) folios
shall never have the page table mapping marked as special.
Fortunately, there are not that many pud_special() check that can be
mislead and are right now rather harmless: e.g., none so far bases
decisions whether to grab a folio reference on that decision.
Well, and GUP-fast will fallback to GUP-slow. All in all, so far no big
implications as it seems.
Getting this right will get more important as we introduce
folio_normal_page_pud() and start using it in more place where we
currently special-case based on other VMA flags.
Fix it just like we fixed vmf_insert_folio_pmd().
Add folio_mk_pud() to mimic what we do with folio_mk_pmd().
Link: https://lkml.kernel.org/r/20250613092702.1943533-4-david@redhat.com
Fixes:
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David Hildenbrand
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c4297465d4 |
mm/huge_memory: don't mark refcounted folios special in vmf_insert_folio_pmd()
Marking PMDs that map a "normal" refcounted folios as special is against
our rules documented for vm_normal_page(): normal (refcounted) folios
shall never have the page table mapping marked as special.
Fortunately, there are not that many pmd_special() check that can be
mislead, and most vm_normal_page_pmd()/vm_normal_folio_pmd() users that
would get this wrong right now are rather harmless: e.g., none so far
bases decisions whether to grab a folio reference on that decision.
Well, and GUP-fast will fallback to GUP-slow. All in all, so far no big
implications as it seems.
Getting this right will get more important as we use
folio_normal_page_pmd() in more places.
Fix it by teaching insert_pfn_pmd() to properly handle folios and pfns --
moving refcount/mapcount/etc handling in there, renaming it to
insert_pmd(), and distinguishing between both cases using a new simple
"struct folio_or_pfn" structure.
Use folio_mk_pmd() to create a pmd for a folio cleanly.
Link: https://lkml.kernel.org/r/20250613092702.1943533-3-david@redhat.com
Fixes:
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David Hildenbrand
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09fefdca80 |
mm/huge_memory: don't ignore queried cachemode in vmf_insert_pfn_pud()
Patch series "mm/huge_memory: vmf_insert_folio_*() and
vmf_insert_pfn_pud() fixes", v3.
While working on improving vm_normal_page() and friends, I stumbled over
this issues: refcounted "normal" folios must not be marked using
pmd_special() / pud_special(). Otherwise, we're effectively telling the
system that these folios are no "normal", violating the rules we
documented for vm_normal_page().
Fortunately, there are not many pmd_special()/pud_special() users yet. So
far there doesn't seem to be serious damage.
Tested using the ndctl tests ("ndctl:dax" suite).
This patch (of 3):
We set up the cache mode but ... don't forward the updated pgprot to
insert_pfn_pud().
Only a problem on x86-64 PAT when mapping PFNs using PUDs that require a
special cachemode.
Fix it by using the proper pgprot where the cachemode was setup.
It is unclear in which configurations we would get the cachemode wrong:
through vfio seems possible. Getting cachemodes wrong is usually ...
bad. As the fix is easy, let's backport it to stable.
Identified by code inspection.
Link: https://lkml.kernel.org/r/20250613092702.1943533-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250613092702.1943533-2-david@redhat.com
Fixes:
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Baolin Wang
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f081a460bb |
selftests: mm: add shmem collapse as a default test item
Currently, we only test anonymous memory collapse by default. We should also add shmem collapse as a default test item to catch issues that could break the test cases. Link: https://lkml.kernel.org/r/a30b1529b399f2e649b5a05c3d352f41a68faeae.1749779183.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Tested-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Baolin Wang
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7962e05a83 |
selftests: khugepaged: fix the shmem collapse failure
When running the khugepaged selftest for shmem (./khugepaged all:shmem), I encountered the following test failures: : Run test: collapse_full (khugepaged:shmem) : Collapse multiple fully populated PTE table.... Fail : ... : Run test: collapse_single_pte_entry (khugepaged:shmem) : Collapse PTE table with single PTE entry present.... Fail : ... : Run test: collapse_full_of_compound (khugepaged:shmem) : Allocate huge page... OK : Split huge page leaving single PTE page table full of compound pages... OK : Collapse PTE table full of compound pages.... Fail The reason for the failure is that it will set MADV_NOHUGEPAGE to prevent khugepaged from continuing to scan shmem VMA after khugepaged finishes scanning in the wait_for_scan() function. Moreover, shmem requires a refault to establish PMD mappings. However, after commit |
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Matthew Wilcox (Oracle)
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234dda7a49 |
mm: remove zero_user()
All users have now been converted to either memzero_page() or folio_zero_range(). Link: https://lkml.kernel.org/r/20250612143443.2848197-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Xiubo Li <xiubli@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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7431f3a201 |
ceph: convert ceph_zero_partial_page() to use a folio
Retrieve a folio from the pagecache instead of a page and operate on it. Removes several hidden calls to compound_head() along with calls to deprecated functions like wait_on_page_writeback() and find_lock_page(). [dan.carpenter@linaro.org: fix NULL vs IS_ERR() bug in ceph_zero_partial_page()] Link: https://lkml.kernel.org/r/685c1424.050a0220.baa8.d6a1@mx.google.com Link: https://lkml.kernel.org/r/20250612143443.2848197-5-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Xiubo Li <xiubli@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Alex Markuze <amarkuze@redhat.com> Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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88b478e55c |
direct-io: use memzero_page()
memzero_page() is the new name for zero_user(). Link: https://lkml.kernel.org/r/20250612143443.2848197-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Xiubo Li <xiubli@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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1a80ff0f88 |
null_blk: use memzero_page()
memzero_page() is the new name for zero_user(). Link: https://lkml.kernel.org/r/20250612143443.2848197-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Xiubo Li <xiubli@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Matthew Wilcox (Oracle)
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ff20487308 |
bio: use memzero_page() in bio_truncate()
Patch series "Remove zero_user()". The zero_user() API is almost unused these days. Finish the job of removing it. This patch (of 5): memzero_page() is the new name for zero_user(). Link: https://lkml.kernel.org/r/20250612143443.2848197-1-willy@infradead.org Link: https://lkml.kernel.org/r/20250612143443.2848197-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ilya Dryomov <idryomov@gmail.com> Cc: Xiubo Li <xiubli@redhat.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Shivank Garg
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a984f16fba |
mm: use folio_expected_ref_count() helper for reference counting
Replace open-coded folio reference count calculations with the folio_expected_ref_count(). No functional changes intended. Link: https://lkml.kernel.org/r/20250611052706.515408-2-shivankg@amd.com Signed-off-by: Shivank Garg <shivankg@amd.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Namhyung kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Pu Lehui
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a788b6e571 |
selftests/mm: use generic read_sysfs in thuge-gen test
As generic read_sysfs is available in vm_utils, let's use is in thuge-gen test. Link: https://lkml.kernel.org/r/20250611100106.1331197-1-pulehui@huaweicloud.com Signed-off-by: Pu Lehui <pulehui@huawei.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Barry Song
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4f8ba33bbd |
mm: madvise: use per_vma lock for MADV_FREE
MADV_FREE is another option, besides MADV_DONTNEED, for dynamic memory freeing in user-space native or Java heap memory management. For example, jemalloc can be configured to use MADV_FREE, and recent versions of the Android Java heap have also increasingly adopted MADV_FREE. Supporting per-VMA locking for MADV_FREE thus appears increasingly necessary. We have replaced walk_page_range() with walk_page_range_vma(). Along with the proposed madvise_lock_mode by Lorenzo, the necessary infrastructure is now in place to begin exploring per-VMA locking support for MADV_FREE and potentially other madvise using walk_page_range_vma(). This patch adds support for the PGWALK_VMA_RDLOCK walk_lock mode in walk_page_range_vma(), and leverages madvise_lock_mode from madv_behavior to select the appropriate walk_lock—either mmap_lock or per-VMA lock—based on the context. Because we now dynamically update the walk_ops->walk_lock field, we must ensure this is thread-safe. The madvise_free_walk_ops is now defined as a stack variable instead of a global constant. Link: https://lkml.kernel.org/r/20250611104745.57405-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: SeongJae Park <sj@kernel.org> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Tangquan Zheng <zhengtangquan@oppo.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Dev Jain
|
f822a9a81a |
mm: optimize mremap() by PTE batching
Use folio_pte_batch() to optimize move_ptes(). On arm64, if the ptes are painted with the contig bit, then ptep_get() will iterate through all 16 entries to collect a/d bits. Hence this optimization will result in a 16x reduction in the number of ptep_get() calls. Next, ptep_get_and_clear() will eventually call contpte_try_unfold() on every contig block, thus flushing the TLB for the complete large folio range. Instead, use get_and_clear_full_ptes() so as to elide TLBIs on each contig block, and only do them on the starting and ending contig block. For split folios, there will be no pte batching; nr_ptes will be 1. For pagetable splitting, the ptes will still point to the same large folio; for arm64, this results in the optimization described above, and for other arches (including the general case), a minor improvement is expected due to a reduction in the number of function calls. Link: https://lkml.kernel.org/r/20250610035043.75448-3-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Barry Song <baohua@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Bang Li <libang.li@antgroup.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: bibo mao <maobibo@loongson.cn> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Dev Jain
|
94dab12d86 |
mm: call pointers to ptes as ptep
Patch series "Optimize mremap() for large folios", v4.
Currently move_ptes() iterates through ptes one by one. If the underlying
folio mapped by the ptes is large, we can process those ptes in a batch
using folio_pte_batch(), thus clearing and setting the PTEs in one go.
For arm64 specifically, this results in a 16x reduction in the number of
ptep_get() calls (since on a contig block, ptep_get() on arm64 will
iterate through all 16 entries to collect a/d bits), and we also elide
extra TLBIs through get_and_clear_full_ptes, replacing ptep_get_and_clear.
Mapping 1M of memory with 64K folios, memsetting it, remapping it to src +
1M, and munmapping it 10,000 times, the average execution time reduces
from 1.9 to 1.2 seconds, giving a 37% performance optimization, on Apple
M3 (arm64). No regression is observed for small folios.
Test program for reference:
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
#include <string.h>
#include <errno.h>
#define SIZE (1UL << 20) // 1M
int main(void) {
void *new_addr, *addr;
for (int i = 0; i < 10000; ++i) {
addr = mmap((void *)(1UL << 30), SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (addr == MAP_FAILED) {
perror("mmap");
return 1;
}
memset(addr, 0xAA, SIZE);
new_addr = mremap(addr, SIZE, SIZE, MREMAP_MAYMOVE | MREMAP_FIXED, addr + SIZE);
if (new_addr != (addr + SIZE)) {
perror("mremap");
return 1;
}
munmap(new_addr, SIZE);
}
}
This patch (of 2):
Avoid confusion between pte_t* and pte_t data types by suffixing pointer
type variables with p. No functional change.
Link: https://lkml.kernel.org/r/20250610035043.75448-1-dev.jain@arm.com
Link: https://lkml.kernel.org/r/20250610035043.75448-2-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Bang Li <libang.li@antgroup.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: bibo mao <maobibo@loongson.cn>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Li Zhijian
|
cce3510313 |
mm/memory-tier: fix abstract distance calculation overflow
In mt_perf_to_adistance(), the calculation of abstract distance (adist)
involves multiplying several int values including
MEMTIER_ADISTANCE_DRAM.
*adist = MEMTIER_ADISTANCE_DRAM *
(perf->read_latency + perf->write_latency) /
(default_dram_perf.read_latency + default_dram_perf.write_latency) *
(default_dram_perf.read_bandwidth + default_dram_perf.write_bandwidth) /
(perf->read_bandwidth + perf->write_bandwidth);
Since these values can be large, the multiplication may exceed the
maximum value of an int (INT_MAX) and overflow (Our platform did),
leading to an incorrect adist.
User-visible impact:
The memory tiering subsystem will misinterpret slow memory (like CXL)
as faster than DRAM, causing inappropriate demotion of pages from
CXL (slow memory) to DRAM (fast memory).
For example, we will see the following demotion chains from the dmesg, where
Node0,1 are DRAM, and Node2,3 are CXL node:
Demotion targets for Node 0: null
Demotion targets for Node 1: null
Demotion targets for Node 2: preferred: 0-1, fallback: 0-1
Demotion targets for Node 3: preferred: 0-1, fallback: 0-1
Change MEMTIER_ADISTANCE_DRAM to be a long constant by writing it with
the 'L' suffix. This prevents the overflow because the multiplication
will then be done in the long type which has a larger range.
Link: https://lkml.kernel.org/r/20250611023439.2845785-1-lizhijian@fujitsu.com
Link: https://lkml.kernel.org/r/20250610062751.2365436-1-lizhijian@fujitsu.com
Fixes:
|
||
|
David Wang
|
9f44df50fe |
alloc_tag: keep codetag iterator active between read()
When reading /proc/allocinfo, for each read syscall, seq_file would invoke
start/stop callbacks. In start callback, a memory is alloced to store
iterator and the iterator would start from beginning to walk linearly to
current read position.
seq_file read() takes at most 4096 bytes, even if read with a larger user
space buffer, meaning read out all of /proc/allocinfo, tens of read
syscalls are needed. For example, a 306036 bytes allocinfo files need 76
reads:
$ sudo cat /proc/allocinfo | wc
3964 16678 306036
$ sudo strace -T -e read cat /proc/allocinfo
...
read(3, " 4096 1 arch/x86/k"..., 131072) = 4063 <0.000062>
...
read(3, " 0 0 sound/core"..., 131072) = 4021 <0.000150>
...
For those n=3964 lines, each read takes about m=3964/76=52 lines,
since iterator restart from beginning for each read(),
it would move forward
m steps on 1st read
2*m steps on 2nd read
3*m steps on 3rd read
...
n steps on last read
As read() along, those linear seek steps make read() calls slower and
slower. Adding those up, codetag iterator moves about O(n*n/m) steps,
making data structure traversal take significant part of the whole
reading. Profiling when stress reading /proc/allocinfo confirms it:
vfs_read(99.959% 1677299/1677995)
proc_reg_read_iter(99.856% 1674881/1677299)
seq_read_iter(99.959% 1674191/1674881)
allocinfo_start(75.664% 1266755/1674191)
codetag_next_ct(79.217% 1003487/1266755) <---
srso_return_thunk(1.264% 16011/1266755)
__kmalloc_cache_noprof(0.102% 1296/1266755)
...
allocinfo_show(21.287% 356378/1674191)
allocinfo_next(1.530% 25621/1674191)
codetag_next_ct() takes major part.
A private data alloced at open() time can be used to carry iterator alive
across read() calls, and avoid the memory allocation and iterator reset
for each read(). This way, only O(1) memory allocation and O(n) steps
iterating, and `time` shows performance improvement from ~7ms to ~4ms.
Profiling with the change:
vfs_read(99.865% 1581073/1583214)
proc_reg_read_iter(99.485% 1572934/1581073)
seq_read_iter(99.846% 1570519/1572934)
allocinfo_show(87.428% 1373074/1570519)
seq_buf_printf(83.695% 1149196/1373074)
seq_buf_putc(1.917% 26321/1373074)
_find_next_bit(1.531% 21023/1373074)
...
codetag_to_text(0.490% 6727/1373074)
...
allocinfo_next(6.275% 98543/1570519)
...
allocinfo_start(0.369% 5790/1570519)
...
Now seq_buf_printf() takes major part.
Link: https://lkml.kernel.org/r/20250609064408.112783-1-00107082@163.com
Signed-off-by: David Wang <00107082@163.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
David Wang
|
b0da7709c2 |
alloc_tag: add sequence number for module and iterator
Codetag iterator use <id,address> pair to guarantee the validness. But both id and address can be reused, there is theoretical possibility when module inserted right after another module removed, kmalloc returns an address same as the address kfree by previous module and IDR key reuses the key recently removed. Add a sequence number to codetag_module and code_iterator, the sequence number is strickly incremented whenever a module is loaded. An iterator is valid if and only if its sequence number match codetag_module's. Link: https://lkml.kernel.org/r/20250609064200.112639-1-00107082@163.com Signed-off-by: David Wang <00107082@163.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Li Zhe
|
a03db236ae |
gup: optimize longterm pin_user_pages() for large folio
In the current implementation of longterm pin_user_pages(), we invoke
collect_longterm_unpinnable_folios(). This function iterates through the
list to check whether each folio belongs to the "longterm_unpinnabled"
category. The folios in this list essentially correspond to a contiguous
region of userspace addresses, with each folio representing a physical
address in increments of PAGESIZE.
If this userspace address range is mapped with large folio, we can
optimize the performance of function collect_longterm_unpinnable_folios()
by reducing the using of READ_ONCE() invoked in
pofs_get_folio()->page_folio()->_compound_head().
Also, we can simplify the logic of collect_longterm_unpinnable_folios().
Instead of comparing with prev_folio after calling pofs_get_folio(), we
can check whether the next page is within the same folio.
The performance test results, based on v6.15, obtained through the
gup_test tool from the kernel source tree are as follows. We achieve an
improvement of over 66% for large folio with pagesize=2M. For small
folio, we have only observed a very slight degradation in performance.
Without this patch:
[root@localhost ~] ./gup_test -HL -m 8192 -n 512
TAP version 13
1..1
# PIN_LONGTERM_BENCHMARK: Time: get:14391 put:10858 us#
ok 1 ioctl status 0
# Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
[root@localhost ~]# ./gup_test -LT -m 8192 -n 512
TAP version 13
1..1
# PIN_LONGTERM_BENCHMARK: Time: get:130538 put:31676 us#
ok 1 ioctl status 0
# Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
With this patch:
[root@localhost ~] ./gup_test -HL -m 8192 -n 512
TAP version 13
1..1
# PIN_LONGTERM_BENCHMARK: Time: get:4867 put:10516 us#
ok 1 ioctl status 0
# Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
[root@localhost ~]# ./gup_test -LT -m 8192 -n 512
TAP version 13
1..1
# PIN_LONGTERM_BENCHMARK: Time: get:131798 put:31328 us#
ok 1 ioctl status 0
# Totals: pass:1 fail:0 xfail:0 xpass:0 skip:0 error:0
[lizhe.67@bytedance.com: whitespace fix, per David]
Link: https://lkml.kernel.org/r/20250606091917.91384-1-lizhe.67@bytedance.com
Link: https://lkml.kernel.org/r/20250606023742.58344-1-lizhe.67@bytedance.com
Signed-off-by: Li Zhe <lizhe.67@bytedance.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Lorenzo Stoakes
|
96d81e4766 |
mm/pagewalk: split walk_page_range_novma() into kernel/user parts
walk_page_range_novma() is rather confusing - it supports two modes, one used often, the other used only for debugging. The first mode is the common case of traversal of kernel page tables, which is what nearly all callers use this for. Secondly it provides an unusual debugging interface that allows for the traversal of page tables in a userland range of memory even for that memory which is not described by a VMA. It is far from certain that such page tables should even exist, but perhaps this is precisely why it is useful as a debugging mechanism. As a result, this is utilised by ptdump only. Historically, things were reversed - ptdump was the only user, and other parts of the kernel evolved to use the kernel page table walking here. Since we have some complicated and confusing locking rules for the novma case, it makes sense to separate the two usages into their own functions. Doing this also provide self-documentation as to the intent of the caller - are they doing something rather unusual or are they simply doing a standard kernel page table walk? We therefore establish two separate functions - walk_page_range_debug() for this single usage, and walk_kernel_page_table_range() for general kernel page table walking. The walk_page_range_debug() function is currently used to traverse both userland and kernel mappings, so we maintain this and in the case of kernel mappings being traversed, we have walk_page_range_debug() invoke walk_kernel_page_table_range() internally. We additionally make walk_page_range_debug() internal to mm. Link: https://lkml.kernel.org/r/20250605135104.90720-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Barry Song <baohua@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: WANG Xuerui <kernel@xen0n.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Ye Liu
|
03dfefdacf |
mm/memfd: clarify error handling labels in memfd_create()
err_name --> err_free_name (fd failure case) err_fd --> err_free_fd (file failure case) Link: https://lkml.kernel.org/r/20250610083730.527619-1-ye.liu@linux.dev Signed-off-by: Ye Liu <liuye@kylinos.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Arnd Bergmann
|
6046a3bed1 |
lib/test_hmm: reduce stack usage
The various test ioctl handlers use arrays of 64 integers that add up to 1KiB of stack data, which in turn leads to exceeding the warning limit in some configurations: lib/test_hmm.c:935:12: error: stack frame size (1408) exceeds limit (1280) in 'dmirror_migrate_to_device' [-Werror,-Wframe-larger-than] Use half the size for these arrays, in order to stay under the warning limits. The code can already deal with arbitrary lengths, but this may be a little less efficient. Link: https://lkml.kernel.org/r/20250610092159.2639515-1-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alistair Popple <apopple@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jeff Johnson <jeff.johnson@oss.qualcomm.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Mark Brown
|
ba78585585 |
selftests/mm: check for YAMA ptrace_scope configuraiton before modifying it
When running the memfd_secret test run_vmtests.sh unconditionally tries to confgiure the YAMA LSM's ptrace_scope configuration, leading to an error if YAMA is not in the running kernel: # ./run_vmtests.sh: line 432: /proc/sys/kernel/yama/ptrace_scope: No such file or directory # # ---------------------- # # running ./memfd_secret # # ---------------------- Check that this file is present before trying to write to it. The indentation here is a bit odd, and it doesn't seem great that we configure but don't restore ptrace_scope. Link: https://lkml.kernel.org/r/20250610-selftest-mm-enable-yama-v1-1-0097b6713116@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Mark Brown
|
4ff52d4a2d |
selftests/mm: add messages about test errors to the cow tests
It is not sufficiently clear what the individual tests in the cow test program are checking so add messages for the failure cases. Link: https://lkml.kernel.org/r/20250610-selftest-mm-cow-tweaks-v1-4-43cd7457500f@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Mark Brown
|
32dc2d5e3f |
selftests/mm: don't compare return values to in cow
Tweak the coding style for checking for non-zero return values. While we're at it also remove a now redundant oring of the madvise() return code. Link: https://lkml.kernel.org/r/20250610-selftest-mm-cow-tweaks-v1-3-43cd7457500f@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Mark Brown
|
5fbfb1f39d |
selftests/mm: convert some cow error reports to ksft_perror()
This prints the errno and a string decode of it. Link: https://lkml.kernel.org/r/20250610-selftest-mm-cow-tweaks-v1-2-43cd7457500f@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Mark Brown
|
be3d3343d4 |
kselftest/mm: clarify errors for pipe()
Patch series "selftests/mm: Tweaks to the cow test". A collection of non-functional updates from David Hildenbrand's review. This patch (of 4): Specify that errors reported from pipe() failures are the result of failures. Link: https://lkml.kernel.org/r/20250610-selftest-mm-cow-tweaks-v1-0-43cd7457500f@kernel.org Link: https://lkml.kernel.org/r/20250610-selftest-mm-cow-tweaks-v1-1-43cd7457500f@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Mark Brown <broonie@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Casey Chen
|
7e43195c60 |
alloc_tag: remove empty module tag section
The empty MOD_CODETAG_SECTIONS() macro added an incomplete .data section in module linker script, which caused symbol lookup tools like gdb to misinterpret symbol addresses e.g., __ib_process_cq incorrectly mapping to unrelated functions like below. (gdb) disas __ib_process_cq Dump of assembler code for function trace_event_fields_cq_schedule: Removing the empty section restores proper symbol resolution and layout, ensuring .data placement behaves as expected. Link: https://lkml.kernel.org/r/20250610162258.324645-1-cachen@purestorage.com Fixes: |
||
|
Ryan Roberts
|
38b0ece6d7 |
mm/filemap: allow arch to request folio size for exec memory
Change the readahead config so that if it is being requested for an executable mapping, do a synchronous read into a set of folios with an arch-specified order and in a naturally aligned manner. We no longer center the read on the faulting page but simply align it down to the previous natural boundary. Additionally, we don't bother with an asynchronous part. On arm64 if memory is physically contiguous and naturally aligned to the "contpte" size, we can use contpte mappings, which improves utilization of the TLB. When paired with the "multi-size THP" feature, this works well to reduce dTLB pressure. However iTLB pressure is still high due to executable mappings having a low likelihood of being in the required folio size and mapping alignment, even when the filesystem supports readahead into large folios (e.g. XFS). The reason for the low likelihood is that the current readahead algorithm starts with an order-0 folio and increases the folio order by 2 every time the readahead mark is hit. But most executable memory tends to be accessed randomly and so the readahead mark is rarely hit and most executable folios remain order-0. So let's special-case the read(ahead) logic for executable mappings. The trade-off is performance improvement (due to more efficient storage of the translations in iTLB) vs potential for making reclaim more difficult (due to the folios being larger so if a part of the folio is hot the whole thing is considered hot). But executable memory is a small portion of the overall system memory so I doubt this will even register from a reclaim perspective. I've chosen 64K folio size for arm64 which benefits both the 4K and 16K base page size configs. Crucially the same amount of data is still read (usually 128K) so I'm not expecting any read amplification issues. I don't anticipate any write amplification because text is always RO. Note that the text region of an ELF file could be populated into the page cache for other reasons than taking a fault in a mmapped area. The most common case is due to the loader read()ing the header which can be shared with the beginning of text. So some text will still remain in small folios, but this simple, best effort change provides good performance improvements as is. Confine this special-case approach to the bounds of the VMA. This prevents wasting memory for any padding that might exist in the file between sections. Previously the padding would have been contained in order-0 folios and would be easy to reclaim. But now it would be part of a larger folio so more difficult to reclaim. Solve this by simply not reading it into memory in the first place. Benchmarking ============ The below shows pgbench and redis benchmarks on Graviton3 arm64 system. First, confirmation that this patch causes more text to be contained in 64K folios: +----------------------+---------------+---------------+---------------+ | File-backed folios by| system boot | pgbench | redis | | size as percentage of+-------+-------+-------+-------+-------+-------+ | all mapped text mem |before | after |before | after |before | after | +======================+=======+=======+=======+=======+=======+=======+ | base-page-4kB | 78% | 30% | 78% | 11% | 73% | 14% | | thp-aligned-8kB | 1% | 0% | 0% | 0% | 1% | 0% | | thp-aligned-16kB | 17% | 4% | 17% | 3% | 20% | 4% | | thp-aligned-32kB | 1% | 1% | 1% | 2% | 1% | 1% | | thp-aligned-64kB | 3% | 63% | 3% | 81% | 4% | 77% | | thp-aligned-128kB | 0% | 1% | 1% | 1% | 1% | 2% | | thp-unaligned-64kB | 0% | 0% | 0% | 1% | 0% | 1% | | thp-unaligned-128kB | 0% | 1% | 0% | 0% | 0% | 0% | | thp-partial | 0% | 0% | 0% | 1% | 0% | 1% | +----------------------+-------+-------+-------+-------+-------+-------+ | cont-aligned-64kB | 4% | 65% | 4% | 83% | 6% | 79% | +----------------------+-------+-------+-------+-------+-------+-------+ The above shows that for both workloads (each isolated with cgroups) as well as the general system state after boot, the amount of text backed by 4K and 16K folios reduces and the amount backed by 64K folios increases significantly. And the amount of text that is contpte-mapped significantly increases (see last row). And this is reflected in performance improvement. "(I)" indicates a statistically significant improvement. Note TPS and Reqs/sec are rates so bigger is better, ms is time so smaller is better: +-------------+-------------------------------------------+------------+ | Benchmark | Result Class | Improvemnt | +=============+===========================================+============+ | pts/pgbench | Scale: 1 Clients: 1 RO (TPS) | (I) 3.47% | | | Scale: 1 Clients: 1 RO - Latency (ms) | -2.88% | | | Scale: 1 Clients: 250 RO (TPS) | (I) 5.02% | | | Scale: 1 Clients: 250 RO - Latency (ms) | (I) -4.79% | | | Scale: 1 Clients: 1000 RO (TPS) | (I) 6.16% | | | Scale: 1 Clients: 1000 RO - Latency (ms) | (I) -5.82% | | | Scale: 100 Clients: 1 RO (TPS) | 2.51% | | | Scale: 100 Clients: 1 RO - Latency (ms) | -3.51% | | | Scale: 100 Clients: 250 RO (TPS) | (I) 4.75% | | | Scale: 100 Clients: 250 RO - Latency (ms) | (I) -4.44% | | | Scale: 100 Clients: 1000 RO (TPS) | (I) 6.34% | | | Scale: 100 Clients: 1000 RO - Latency (ms)| (I) -5.95% | +-------------+-------------------------------------------+------------+ | pts/redis | Test: GET Connections: 50 (Reqs/sec) | (I) 3.20% | | | Test: GET Connections: 1000 (Reqs/sec) | (I) 2.55% | | | Test: LPOP Connections: 50 (Reqs/sec) | (I) 4.59% | | | Test: LPOP Connections: 1000 (Reqs/sec) | (I) 4.81% | | | Test: LPUSH Connections: 50 (Reqs/sec) | (I) 5.31% | | | Test: LPUSH Connections: 1000 (Reqs/sec) | (I) 4.36% | | | Test: SADD Connections: 50 (Reqs/sec) | (I) 2.64% | | | Test: SADD Connections: 1000 (Reqs/sec) | (I) 4.15% | | | Test: SET Connections: 50 (Reqs/sec) | (I) 3.11% | | | Test: SET Connections: 1000 (Reqs/sec) | (I) 3.36% | +-------------+-------------------------------------------+------------+ [ryan.roberts@arm.com: fix use-after-free] Link: https://lkml.kernel.org/r/ea7f9da7-9a9f-4b85-9d0a-35b320f5ed25@arm.com [ryan.roberts@arm.com: use the vma_pages() helper instead of open-coding] Link: https://lkml.kernel.org/r/0e0f674b-3b7e-494f-ae7a-fc9dbb98dad4@arm.com Link: https://lkml.kernel.org/r/20250609092729.274960-6-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Will Deacon <will@kernel.org> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ryan Roberts
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c4602f9fa7 |
mm/readahead: store folio order in struct file_ra_state
Previously the folio order of the previous readahead request was inferred from the folio who's readahead marker was hit. But due to the way we have to round to non-natural boundaries sometimes, this first folio in the readahead block is often smaller than the preferred order for that request. This means that for cases where the initial sync readahead is poorly aligned, the folio order will ramp up much more slowly. So instead, let's store the order in struct file_ra_state so we are not affected by any required alignment. We previously made enough room in the struct for a 16 order field. This should be plenty big enough since we are limited to MAX_PAGECACHE_ORDER anyway, which is certainly never larger than ~20. Since we now pass order in struct file_ra_state, page_cache_ra_order() no longer needs it's new_order parameter, so let's remove that. Worked example: Here we are touching pages 17-256 sequentially just as we did in the previous commit, but now that we are remembering the preferred order explicitly, we no longer have the slow ramp up problem. Note specifically that we no longer have 2 rounds (2x ~128K) of order-2 folios: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00001000 4096 0 1 1 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00021000 4096 32 33 1 0 FOLIO 0x00021000 0x00022000 4096 33 34 1 0 FOLIO 0x00022000 0x00024000 8192 34 36 2 1 FOLIO 0x00024000 0x00028000 16384 36 40 4 2 FOLIO 0x00028000 0x0002c000 16384 40 44 4 2 FOLIO 0x0002c000 0x00030000 16384 44 48 4 2 FOLIO 0x00030000 0x00034000 16384 48 52 4 2 FOLIO 0x00034000 0x00038000 16384 52 56 4 2 FOLIO 0x00038000 0x0003c000 16384 56 60 4 2 FOLIO 0x0003c000 0x00040000 16384 60 64 4 2 FOLIO 0x00040000 0x00050000 65536 64 80 16 4 FOLIO 0x00050000 0x00060000 65536 80 96 16 4 FOLIO 0x00060000 0x00080000 131072 96 128 32 5 FOLIO 0x00080000 0x000a0000 131072 128 160 32 5 FOLIO 0x000a0000 0x000c0000 131072 160 192 32 5 FOLIO 0x000c0000 0x000e0000 131072 192 224 32 5 FOLIO 0x000e0000 0x00100000 131072 224 256 32 5 FOLIO 0x00100000 0x00120000 131072 256 288 32 5 FOLIO 0x00120000 0x00140000 131072 288 320 32 5 Y HOLE 0x00140000 0x00800000 7077888 320 2048 1728 Link: https://lkml.kernel.org/r/20250609092729.274960-5-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ryan Roberts
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f5e8b140cd |
mm/readahead: make space in struct file_ra_state
We need to be able to store the preferred folio order associated with a readahead request in the struct file_ra_state so that we can more accurately increase the order across subsequent readahead requests. But struct file_ra_state is per-struct file, so we don't really want to increase it's size. mmap_miss is currently 32 bits but it is only counted up to 10 * MMAP_LOTSAMISS, which is currently defined as 1000. So 16 bits should be plenty. Redefine it to unsigned short, making room for order as unsigned short in follow up commit. Link: https://lkml.kernel.org/r/20250609092729.274960-4-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ryan Roberts
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18ebe55a92 |
mm/readahead: terminate async readahead on natural boundary
Previously asynchonous readahead would read ra_pages (usually 128K) directly after the end of the synchonous readahead and given the synchronous readahead portion had no alignment guarantees (beyond page boundaries) it is possible (and likely) that the end of the initial 128K region would not fall on a natural boundary for the folio size being used. Therefore smaller folios were used to align down to the required boundary, both at the end of the previous readahead block and at the start of the new one. In the worst cases, this can result in never properly ramping up the folio size, and instead getting stuck oscillating between order-0, -1 and -2 folios. The next readahead will try to use folios whose order is +2 bigger than the folio that had the readahead marker. But because of the alignment requirements, that folio (the first one in the readahead block) can end up being order-0 in some cases. There will be 2 modifications to solve this issue: 1) Calculate the readahead size so the end is aligned to a folio boundary. This prevents needing to allocate small folios to align down at the end of the window and fixes the oscillation problem. 2) Remember the "preferred folio order" in the ra state instead of inferring it from the folio with the readahead marker. This solves the slow ramp up problem (discussed in a subsequent patch). This patch addresses (1) only. A subsequent patch will address (2). Worked example: The following shows the previous pathalogical behaviour when the initial synchronous readahead is unaligned. We start reading at page 17 in the file and read sequentially from there. I'm showing a dump of the pages in the page cache just after we read the first page of the folio with the readahead marker. Initially there are no pages in the page cache: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00800000 8388608 0 2048 2048 Then we access page 17, causing synchonous read-around of 128K with a readahead marker set up at page 25. So far, all as expected: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00001000 4096 0 1 1 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 Y FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00021000 4096 32 33 1 0 HOLE 0x00021000 0x00800000 8253440 33 2048 2015 Now access pages 18-25 inclusive. This causes an asynchronous 128K readahead starting at page 33. But since we are unaligned, even though the preferred folio order is 2, the first folio in this batch (the one with the new readahead marker) is order-0: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00001000 4096 0 1 1 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00021000 4096 32 33 1 0 FOLIO 0x00021000 0x00022000 4096 33 34 1 0 Y FOLIO 0x00022000 0x00024000 8192 34 36 2 1 FOLIO 0x00024000 0x00028000 16384 36 40 4 2 FOLIO 0x00028000 0x0002c000 16384 40 44 4 2 FOLIO 0x0002c000 0x00030000 16384 44 48 4 2 FOLIO 0x00030000 0x00034000 16384 48 52 4 2 FOLIO 0x00034000 0x00038000 16384 52 56 4 2 FOLIO 0x00038000 0x0003c000 16384 56 60 4 2 FOLIO 0x0003c000 0x00040000 16384 60 64 4 2 FOLIO 0x00040000 0x00041000 4096 64 65 1 0 HOLE 0x00041000 0x00800000 8122368 65 2048 1983 Which means that when we now read pages 26-33 and readahead is kicked off again, the new preferred order is 2 (0 + 2), not 4 as we intended: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00001000 4096 0 1 1 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00021000 4096 32 33 1 0 FOLIO 0x00021000 0x00022000 4096 33 34 1 0 FOLIO 0x00022000 0x00024000 8192 34 36 2 1 FOLIO 0x00024000 0x00028000 16384 36 40 4 2 FOLIO 0x00028000 0x0002c000 16384 40 44 4 2 FOLIO 0x0002c000 0x00030000 16384 44 48 4 2 FOLIO 0x00030000 0x00034000 16384 48 52 4 2 FOLIO 0x00034000 0x00038000 16384 52 56 4 2 FOLIO 0x00038000 0x0003c000 16384 56 60 4 2 FOLIO 0x0003c000 0x00040000 16384 60 64 4 2 FOLIO 0x00040000 0x00041000 4096 64 65 1 0 FOLIO 0x00041000 0x00042000 4096 65 66 1 0 Y FOLIO 0x00042000 0x00044000 8192 66 68 2 1 FOLIO 0x00044000 0x00048000 16384 68 72 4 2 FOLIO 0x00048000 0x0004c000 16384 72 76 4 2 FOLIO 0x0004c000 0x00050000 16384 76 80 4 2 FOLIO 0x00050000 0x00054000 16384 80 84 4 2 FOLIO 0x00054000 0x00058000 16384 84 88 4 2 FOLIO 0x00058000 0x0005c000 16384 88 92 4 2 FOLIO 0x0005c000 0x00060000 16384 92 96 4 2 FOLIO 0x00060000 0x00061000 4096 96 97 1 0 HOLE 0x00061000 0x00800000 7991296 97 2048 1951 This ramp up from order-0 with smaller orders at the edges for alignment cycle continues all the way to the end of the file (not shown). After the change, we round down the end boundary to the order boundary so we no longer get stuck in the cycle and can ramp up the order over time. Note that the rate of the ramp up is still not as we would expect it. We will fix that next. Here we are touching pages 17-256 sequentially: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER RA ----- ---------- ---------- ---------- ------- ------- ----- ----- -- HOLE 0x00000000 0x00001000 4096 0 1 1 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00021000 4096 32 33 1 0 FOLIO 0x00021000 0x00022000 4096 33 34 1 0 FOLIO 0x00022000 0x00024000 8192 34 36 2 1 FOLIO 0x00024000 0x00028000 16384 36 40 4 2 FOLIO 0x00028000 0x0002c000 16384 40 44 4 2 FOLIO 0x0002c000 0x00030000 16384 44 48 4 2 FOLIO 0x00030000 0x00034000 16384 48 52 4 2 FOLIO 0x00034000 0x00038000 16384 52 56 4 2 FOLIO 0x00038000 0x0003c000 16384 56 60 4 2 FOLIO 0x0003c000 0x00040000 16384 60 64 4 2 FOLIO 0x00040000 0x00044000 16384 64 68 4 2 FOLIO 0x00044000 0x00048000 16384 68 72 4 2 FOLIO 0x00048000 0x0004c000 16384 72 76 4 2 FOLIO 0x0004c000 0x00050000 16384 76 80 4 2 FOLIO 0x00050000 0x00054000 16384 80 84 4 2 FOLIO 0x00054000 0x00058000 16384 84 88 4 2 FOLIO 0x00058000 0x0005c000 16384 88 92 4 2 FOLIO 0x0005c000 0x00060000 16384 92 96 4 2 FOLIO 0x00060000 0x00070000 65536 96 112 16 4 FOLIO 0x00070000 0x00080000 65536 112 128 16 4 FOLIO 0x00080000 0x000a0000 131072 128 160 32 5 FOLIO 0x000a0000 0x000c0000 131072 160 192 32 5 FOLIO 0x000c0000 0x000e0000 131072 192 224 32 5 FOLIO 0x000e0000 0x00100000 131072 224 256 32 5 FOLIO 0x00100000 0x00120000 131072 256 288 32 5 FOLIO 0x00120000 0x00140000 131072 288 320 32 5 Y HOLE 0x00140000 0x00800000 7077888 320 2048 1728 Link: https://lkml.kernel.org/r/20250609092729.274960-3-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Ryan Roberts
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bdb86f6b87 |
mm/readahead: honour new_order in page_cache_ra_order()
Patch series "Readahead tweaks for larger folios", v5. This series adds some tweaks to readahead so that it does a better job of ramping up folio sizes as readahead extends further into the file. And it additionally special-cases executable mappings to allow the arch to request a preferred folio size for text. This patch (of 5): page_cache_ra_order() takes a parameter called new_order, which is intended to express the preferred order of the folios that will be allocated for the readahead operation. Most callers indeed call this with their preferred new order. But page_cache_async_ra() calls it with the preferred order of the previous readahead request (actually the order of the folio that had the readahead marker, which may be smaller when alignment comes into play). And despite the parameter name, page_cache_ra_order() always treats it at the old order, adding 2 to it on entry. As a result, a cold readahead always starts with order-2 folios. Let's fix this behaviour by always passing in the *new* order. Worked example: Prior to the change, mmaping an 8MB file and touching each page sequentially, resulted in the following, where we start with order-2 folios for the first 128K then ramp up to order-4 for the next 128K, then get clamped to order-5 for the rest of the file because pa_pages is limited to 128K: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER ----- ---------- ---------- --------- ------- ------- ----- ----- FOLIO 0x00000000 0x00004000 16384 0 4 4 2 FOLIO 0x00004000 0x00008000 16384 4 8 4 2 FOLIO 0x00008000 0x0000c000 16384 8 12 4 2 FOLIO 0x0000c000 0x00010000 16384 12 16 4 2 FOLIO 0x00010000 0x00014000 16384 16 20 4 2 FOLIO 0x00014000 0x00018000 16384 20 24 4 2 FOLIO 0x00018000 0x0001c000 16384 24 28 4 2 FOLIO 0x0001c000 0x00020000 16384 28 32 4 2 FOLIO 0x00020000 0x00030000 65536 32 48 16 4 FOLIO 0x00030000 0x00040000 65536 48 64 16 4 FOLIO 0x00040000 0x00060000 131072 64 96 32 5 FOLIO 0x00060000 0x00080000 131072 96 128 32 5 FOLIO 0x00080000 0x000a0000 131072 128 160 32 5 FOLIO 0x000a0000 0x000c0000 131072 160 192 32 5 ... After the change, the same operation results in the first 128K being order-0, then we start ramping up to order-2, -4, and finally get clamped at order-5: TYPE STARTOFFS ENDOFFS SIZE STARTPG ENDPG NRPG ORDER ----- ---------- ---------- --------- ------- ------- ----- ----- FOLIO 0x00000000 0x00001000 4096 0 1 1 0 FOLIO 0x00001000 0x00002000 4096 1 2 1 0 FOLIO 0x00002000 0x00003000 4096 2 3 1 0 FOLIO 0x00003000 0x00004000 4096 3 4 1 0 FOLIO 0x00004000 0x00005000 4096 4 5 1 0 FOLIO 0x00005000 0x00006000 4096 5 6 1 0 FOLIO 0x00006000 0x00007000 4096 6 7 1 0 FOLIO 0x00007000 0x00008000 4096 7 8 1 0 FOLIO 0x00008000 0x00009000 4096 8 9 1 0 FOLIO 0x00009000 0x0000a000 4096 9 10 1 0 FOLIO 0x0000a000 0x0000b000 4096 10 11 1 0 FOLIO 0x0000b000 0x0000c000 4096 11 12 1 0 FOLIO 0x0000c000 0x0000d000 4096 12 13 1 0 FOLIO 0x0000d000 0x0000e000 4096 13 14 1 0 FOLIO 0x0000e000 0x0000f000 4096 14 15 1 0 FOLIO 0x0000f000 0x00010000 4096 15 16 1 0 FOLIO 0x00010000 0x00011000 4096 16 17 1 0 FOLIO 0x00011000 0x00012000 4096 17 18 1 0 FOLIO 0x00012000 0x00013000 4096 18 19 1 0 FOLIO 0x00013000 0x00014000 4096 19 20 1 0 FOLIO 0x00014000 0x00015000 4096 20 21 1 0 FOLIO 0x00015000 0x00016000 4096 21 22 1 0 FOLIO 0x00016000 0x00017000 4096 22 23 1 0 FOLIO 0x00017000 0x00018000 4096 23 24 1 0 FOLIO 0x00018000 0x00019000 4096 24 25 1 0 FOLIO 0x00019000 0x0001a000 4096 25 26 1 0 FOLIO 0x0001a000 0x0001b000 4096 26 27 1 0 FOLIO 0x0001b000 0x0001c000 4096 27 28 1 0 FOLIO 0x0001c000 0x0001d000 4096 28 29 1 0 FOLIO 0x0001d000 0x0001e000 4096 29 30 1 0 FOLIO 0x0001e000 0x0001f000 4096 30 31 1 0 FOLIO 0x0001f000 0x00020000 4096 31 32 1 0 FOLIO 0x00020000 0x00024000 16384 32 36 4 2 FOLIO 0x00024000 0x00028000 16384 36 40 4 2 FOLIO 0x00028000 0x0002c000 16384 40 44 4 2 FOLIO 0x0002c000 0x00030000 16384 44 48 4 2 FOLIO 0x00030000 0x00034000 16384 48 52 4 2 FOLIO 0x00034000 0x00038000 16384 52 56 4 2 FOLIO 0x00038000 0x0003c000 16384 56 60 4 2 FOLIO 0x0003c000 0x00040000 16384 60 64 4 2 FOLIO 0x00040000 0x00050000 65536 64 80 16 4 FOLIO 0x00050000 0x00060000 65536 80 96 16 4 FOLIO 0x00060000 0x00080000 131072 96 128 32 5 FOLIO 0x00080000 0x000a0000 131072 128 160 32 5 FOLIO 0x000a0000 0x000c0000 131072 160 192 32 5 FOLIO 0x000c0000 0x000e0000 131072 192 224 32 5 ... Link: https://lkml.kernel.org/r/20250609092729.274960-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20250609092729.274960-2-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Chaitanya S Prakash <chaitanyas.prakash@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Joshua Hahn
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1ec8a6e30e |
mm/mempolicy: skip unnecessary synchronize_rcu()
By unconditionally setting wi_state to NULL and conditionally calling synchronize_rcu(), we can save an unncessary call when there is no old_wi_state. Link: https://lkml.kernel.org/r/20250602162345.2595696-2-joshua.hahnjy@gmail.com Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: kernel test robot <lkp@intel.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Dev Jain
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1e6b17b423 |
xarray: add a BUG_ON() to ensure caller is not sibling
Suppose xas is pointing somewhere near the end of the multi-entry batch. Then it may happen that the computed slot already falls beyond the batch, thus breaking the loop due to !xa_is_sibling(), and computing the wrong order. For example, suppose we have a shift-6 node having an order-9 entry => 8 - 1 = 7 siblings, so assume the slots are at offset 0 till 7 in this node. If xas->xa_offset is 6, then the code will compute order as 1 + xas->xa_node->shift = 7. Therefore, the order computation must start from the beginning of the multi-slot entries, that is, the non-sibling entry. Thus ensure that the caller is aware of this by triggering a BUG when the entry is a sibling entry. Note that this BUG_ON() is only active while running selftests, so there is no overhead in a running kernel. Link: https://lkml.kernel.org/r/20250604041533.91198-1-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: Zi Yan <ziy@nvidia.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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wangzijie
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ff7ec8dc1b |
proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al
Check pde->proc_ops->proc_lseek directly may cause UAF in rmmod scenario.
It's a gap in proc_reg_open() after commit 654b33ada4ab("proc: fix UAF in
proc_get_inode()"). Followed by AI Viro's suggestion, fix it in same
manner.
Link: https://lkml.kernel.org/r/20250607021353.1127963-1-wangzijie1@honor.com
Fixes:
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Barry Song
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a6fde7add7 |
mm: use per_vma lock for MADV_DONTNEED
Certain madvise operations, especially MADV_DONTNEED, occur far more frequently than other madvise options, particularly in native and Java heaps for dynamic memory management. Currently, the mmap_lock is always held during these operations, even when unnecessary. This causes lock contention and can lead to severe priority inversion, where low-priority threads—such as Android's HeapTaskDaemon— hold the lock and block higher-priority threads. This patch enables the use of per-VMA locks when the advised range lies entirely within a single VMA, avoiding the need for full VMA traversal. In practice, userspace heaps rarely issue MADV_DONTNEED across multiple VMAs. Tangquan's testing shows that over 99.5% of memory reclaimed by Android benefits from this per-VMA lock optimization. After extended runtime, 217,735 madvise calls from HeapTaskDaemon used the per-VMA path, while only 1,231 fell back to mmap_lock. To simplify handling, the implementation falls back to the standard mmap_lock if userfaultfd is enabled on the VMA, avoiding the complexity of userfaultfd_remove(). Many thanks to Lorenzo's work[1] on "mm/madvise: support VMA read locks for MADV_DONTNEED[_LOCKED]" Then use this mechanism to permit VMA locking to be done later in the madvise() logic and also to allow altering of the locking mode to permit falling back to an mmap read lock if required." One important point, as pointed out by Jann[2], is that untagged_addr_remote() requires holding mmap_lock. This is because address tagging on x86 and RISC-V is quite complex. Until untagged_addr_remote() becomes atomic—which seems unlikely in the near future—we cannot support per-VMA locks for remote processes. So for now, only local processes are supported. Lance said: : Just to put some numbers on it, I ran a micro-benchmark with 100 : parallel threads, where each thread calls madvise() on its own 1GiB : chunk of 64KiB mTHP-backed memory. The performance gain is huge: : : 1) MADV_DONTNEED saw its average time drop from 0.0508s to 0.0270s : (~47% faster) : : 2) MADV_FREE saw its average time drop from 0.3078s to 0.1095s (~64% : faster) [lorenzo.stoakes@oracle.com: avoid any chance of uninitialised pointer deref] Link: https://lkml.kernel.org/r/309d22ca-6cd9-4601-8402-d441a07d9443@lucifer.local Link: https://lore.kernel.org/all/0b96ce61-a52c-4036-b5b6-5c50783db51f@lucifer.local/ [1] Link: https://lore.kernel.org/all/CAG48ez11zi-1jicHUZtLhyoNPGGVB+ROeAJCUw48bsjk4bbEkA@mail.gmail.com/ [2] Link: https://lkml.kernel.org/r/20250607220150.2980-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Qi Zheng <zhengqi.arch@bytedance.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Tangquan Zheng <zhengtangquan@oppo.com> Cc: Lance Yang <ioworker0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Tal Zussman
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5e00e31867 |
userfaultfd: remove UFFD_CLOEXEC, UFFD_NONBLOCK, and UFFD_FLAGS_SET
UFFD_CLOEXEC, UFFD_NONBLOCK, and UFFD_FLAGS_SET have been unused since
they were added in commit
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