- 05 Mar, 2024 40 commits
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Matthew Wilcox (Oracle) authored
Hugetlb folios still get special treatment, but normal large folios can now be freed by free_unref_folios(). This should have a reasonable performance impact, TBD. Link: https://lkml.kernel.org/r/20240227174254.710559-11-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
Ryan Roberts <ryan.roberts@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Matthew Wilcox (Oracle) authored
Call folio_undo_large_rmappable() if needed. free_unref_page_prepare() destroys the ability to call folio_order(), so stash the order in folio->private for the benefit of the second loop. Link: https://lkml.kernel.org/r/20240227174254.710559-10-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Pass a pointer to the lruvec so we can take advantage of the folio_lruvec_relock_irqsave(). Adjust the calling convention of folio_lruvec_relock_irqsave() to suit and add a page_cache_release() wrapper. Link: https://lkml.kernel.org/r/20240227174254.710559-9-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Break up the list of folios into batches here so that the folios are more likely to be cache hot when doing the rest of the processing. Link: https://lkml.kernel.org/r/20240227174254.710559-8-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Instead of putting the interesting folios on a list, delete the uninteresting one from the folio_batch. Link: https://lkml.kernel.org/r/20240227174254.710559-7-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Almost identical to mem_cgroup_uncharge_list(), except it takes a folio_batch instead of a list_head. Link: https://lkml.kernel.org/r/20240227174254.710559-6-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
There's no need to indirect through release_pages() and iterate over this batch of folios an extra time; we can just use the batch that we have. Link: https://lkml.kernel.org/r/20240227174254.710559-5-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Iterate over a folio_batch rather than a linked list. This is easier for the CPU to prefetch and has a batch count naturally built in so we don't need to track it. Again, this lowers the maximum lock hold time from 32 folios to 15, but I do not expect this to have a significant effect. Link: https://lkml.kernel.org/r/20240227174254.710559-4-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Most of its callees are not yet ready to accept a folio, but we know all of the pages passed in are actually folios because they're linked through ->lru. Link: https://lkml.kernel.org/r/20240227174254.710559-3-willy@infradead.orgSigned-off-by:
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Matthew Wilcox (Oracle) authored
Patch series "Rearrange batched folio freeing", v3. Other than the obvious "remove calls to compound_head" changes, the fundamental belief here is that iterating a linked list is much slower than iterating an array (5-15x slower in my testing). There's also an associated belief that since we iterate the batch of folios three times, we do better when the array is small (ie 15 entries) than we do with a batch that is hundreds of entries long, which only gives us the opportunity for the first pages to fall out of cache by the time we get to the end. It is possible we should increase the size of folio_batch. Hopefully the bots let us know if this introduces any performance regressions. This patch (of 3): By making release_pages() call folios_put(), we can get rid of the calls to compound_head() for the callers that already know they have folios. We can also get rid of the lock_batch tracking as we know the size of the batch is limited by folio_batch. This does reduce the maximum number of pages for which the lruvec lock is held, from SWAP_CLUSTER_MAX (32) to PAGEVEC_SIZE (15). I do not expect this to make a significant difference, but if it does, we can increase PAGEVEC_SIZE to 31. Link: https://lkml.kernel.org/r/20240227174254.710559-1-willy@infradead.org Link: https://lkml.kernel.org/r/20240227174254.710559-2-willy@infradead.orgSigned-off-by:
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Lance Yang authored
Previously, we removed the mm from mm_slot and dropped mm_count if the MMF_THP_DISABLE flag was set. However, we didn't re-add the mm back after clearing the MMF_THP_DISABLE flag. Additionally, We add a check for the MMF_THP_DISABLE flag in hugepage_vma_revalidate(). Link: https://lkml.kernel.org/r/20240227035135.54593-1-ioworker0@gmail.com Fixes: 879c6000 ("mm/khugepaged: bypassing unnecessary scans with MMF_DISABLE_THP check") Signed-off-by:
Lance Yang <ioworker0@gmail.com> Suggested-by:
Yang Shi <shy828301@gmail.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Zach O'Keefe <zokeefe@google.com> Signed-off-by:
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Martin Kaiser authored
Use an unsigned long constant instead of an int constant and a cast. This fixes the checkpatch warning WARNING: Unnecessary typecast of c90 int constant - '(unsigned long) 1' could be '1UL' + align = ((unsigned long) 1) << i; Link: https://lkml.kernel.org/r/20240226191159.39509-4-martin@kaiser.cxSigned-off-by:
Martin Kaiser <martin@kaiser.cx> Reviewed-by:
Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by:
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Martin Kaiser authored
The module is never loaded successfully. Therefore, it'll never be unloaded and we can remove the exit function. Link: https://lkml.kernel.org/r/20240226191159.39509-3-martin@kaiser.cxSigned-off-by:
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Martin Kaiser authored
Fix a typo and change the function name to init_test_configuration. Both caller and definition have the same typo, so the current code already works. Link: https://lkml.kernel.org/r/20240226191159.39509-2-martin@kaiser.cxSigned-off-by:
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David Hildenbrand authored
All users of total_mapcount() are gone, let's remove it. Link: https://lkml.kernel.org/r/20240226141324.278526-3-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Patch series "mm: remove total_mapcount()", v2. Let's remove the remaining user from mm/memfd.c so we can get rid of total_mapcount(). This patch (of 2): Both functions are the remaining users of total_mapcount(). Let's get rid of the calls by converting the code to folios. As it turns out, the code is unnecessarily complicated, especially: 1) We can query the number of pagecache references for a folio simply via folio_nr_pages(). This will handle other folio sizes in the future correctly. 2) The xas_set(xas, page->index + cache_count) call to increment the iterator for large folios is not required. Remove it. Further, simplify the XA_CHECK_SCHED check, counting each entry exactly once. Memfd pages can be swapped out when using shmem; leave xa_is_value() checks in place. Link: https://lkml.kernel.org/r/20240226141324.278526-1-david@redhat.com Link: https://lkml.kernel.org/r/20240226141324.278526-2-david@redhat.comCo-developed-by:
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Zi Yan authored
It is used to test split_huge_page_to_list_to_order for pagecache THPs. Also add test cases for split_huge_page_to_list_to_order via both debugfs. [ziy@nvidia.com: fix issue discovered with NFS] Link: https://lkml.kernel.org/r/262E4DAA-4A78-4328-B745-1355AE356A07@nvidia.com Link: https://lkml.kernel.org/r/20240226205534.1603748-9-zi.yan@sent.comSigned-off-by:
Zi Yan <ziy@nvidia.com> Tested-by:
Aishwarya TCV <aishwarya.tcv@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michal Koutny <mkoutny@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zach O'Keefe <zokeefe@google.com> Cc: Aishwarya TCV <aishwarya.tcv@arm.com> Signed-off-by:
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Zi Yan authored
To split a THP to any lower order pages, we need to reform THPs on subpages at given order and add page refcount based on the new page order. Also we need to reinitialize page_deferred_list after removing the page from the split_queue, otherwise a subsequent split will see list corruption when checking the page_deferred_list again. Note: Anonymous order-1 folio is not supported because _deferred_list, which is used by partially mapped folios, is stored in subpage 2 and an order-1 folio only has subpage 0 and 1. File-backed order-1 folios are fine, since they do not use _deferred_list. [ziy@nvidia.com: fixup per discussion with Ryan] Link: https://lkml.kernel.org/r/494F48CD-1F0F-4CAD-884E-6D48F40AF990@nvidia.com Link: https://lkml.kernel.org/r/20240226205534.1603748-8-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
It adds a new_order parameter to set new page order in page owner. It prepares for upcoming changes to support split huge page to any lower order. Link: https://lkml.kernel.org/r/20240226205534.1603748-7-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
It sets memcg information for the pages after the split. A new parameter new_order is added to tell the order of subpages in the new page, always 0 for now. It prepares for upcoming changes to support split huge page to any lower order. Link: https://lkml.kernel.org/r/20240226205534.1603748-6-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
We do not have non power of two pages, using nr is error prone if nr is not power-of-two. Use page order instead. Link: https://lkml.kernel.org/r/20240226205534.1603748-5-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
We do not have non power of two pages, using nr is error prone if nr is not power-of-two. Use page order instead. Link: https://lkml.kernel.org/r/20240226205534.1603748-4-zi.yan@sent.comSigned-off-by:
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Matthew Wilcox (Oracle) authored
Folios of order 1 have no space to store the deferred list. This is not a problem for the page cache as file-backed folios are never placed on the deferred list. All we need to do is prevent the core MM from touching the deferred list for order 1 folios and remove the code which prevented us from allocating order 1 folios. Link: https://lore.kernel.org/linux-mm/90344ea7-4eec-47ee-5996-0c22f42d6a6a@google.com/ Link: https://lkml.kernel.org/r/20240226205534.1603748-3-zi.yan@sent.comSigned-off-by:
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Zi Yan authored
Patch series "Split a folio to any lower order folios", v5. File folio supports any order and multi-size THP is upstreamed[1], so both file and anonymous folios can be >0 order. Currently, split_huge_page() only splits a huge page to order-0 pages, but splitting to orders higher than 0 might better utilize large folios, if done properly. In addition, Large Block Sizes in XFS support would benefit from it during truncate[2]. This patchset adds support for splitting a large folio to any lower order folios. In addition to this implementation of split_huge_page_to_list_to_order(), a possible optimization could be splitting a large folio to arbitrary smaller folios instead of a single order. As both Hugh and Ryan pointed out [3,5] that split to a single order might not be optimal, an order-9 folio might be better split into 1 order-8, 1 order-7, ..., 1 order-1, and 2 order-0 folios, depending on subsequent folio operations. Leave this as future work. [1] https://lore.kernel.org/all/20231207161211.2374093-1-ryan.roberts@arm.com/ [2] https://lore.kernel.org/linux-mm/20240226094936.2677493-1-kernel@pankajraghav.com/ [3] https://lore.kernel.org/linux-mm/9dd96da-efa2-5123-20d4-4992136ef3ad@google.com/ [4] https://lore.kernel.org/linux-mm/cbb1d6a0-66dd-47d0-8733-f836fe050374@arm.com/ [5] https://lore.kernel.org/linux-mm/20240213215520.1048625-1-zi.yan@sent.com/ This patch (of 8): As multi-size THP support is added, not all THPs are PMD-mapped, thus during a huge page split, there is no need to always split PMD mapping in unmap_folio(). Make it conditional. Link: https://lkml.kernel.org/r/20240226205534.1603748-1-zi.yan@sent.com Link: https://lkml.kernel.org/r/20240226205534.1603748-2-zi.yan@sent.comSigned-off-by:
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Suren Baghdasaryan authored
Introduce GFP bits enumeration to let compiler track the number of used bits (which depends on the config options) instead of hardcoding them. That simplifies __GFP_BITS_SHIFT calculation. Link: https://lkml.kernel.org/r/20240224015800.2569851-1-surenb@google.comSuggested-by:
Petr Tesařík <petr@tesarici.cz> Signed-off-by:
Suren Baghdasaryan <surenb@google.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Reviewed-by:
Pasha Tatashin <pasha.tatashin@soleen.com> Acked-by:
Michal Hocko <mhocko@suse.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Petr Tesarik <petr@tesarici.cz> Signed-off-by:
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Barry Song authored
While doing MADV_PAGEOUT, the current code will clear PTE young so that vmscan won't read young flags to allow the reclamation of madvised folios to go ahead. It seems we can do it by directly ignoring references, thus we can remove tlb flush in madvise and rmap overhead in vmscan. Regarding the side effect, in the original code, if a parallel thread runs side by side to access the madvised memory with the thread doing madvise, folios will get a chance to be re-activated by vmscan (though the time gap is actually quite small since checking PTEs is done immediately after clearing PTEs young). But with this patch, they will still be reclaimed. But this behaviour doing PAGEOUT and doing access at the same time is quite silly like DoS. So probably, we don't need to care. Or ignoring the new access during the quite small time gap is even better. For DAMON's DAMOS_PAGEOUT based on physical address region, we still keep its behaviour as is since a physical address might be mapped by multiple processes. MADV_PAGEOUT based on virtual address is actually much more aggressive on reclamation. To untouch paddr's DAMOS_PAGEOUT, we simply pass ignore_references as false in reclaim_pages(). A microbench as below has shown 6% decrement on the latency of MADV_PAGEOUT, #define PGSIZE 4096 main() { int i; #define SIZE 512*1024*1024 volatile long *p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); for (i = 0; i < SIZE/sizeof(long); i += PGSIZE / sizeof(long)) p[i] = 0x11; madvise(p, SIZE, MADV_PAGEOUT); } w/o patch w/ patch root@10:~# time ./a.out root@10:~# time ./a.out real 0m49.634s real 0m46.334s user 0m0.637s user 0m0.648s sys 0m47.434s sys 0m44.265s Link: https://lkml.kernel.org/r/20240226005739.24350-1-21cnbao@gmail.comSigned-off-by:Barry Song <v-songbaohua@oppo.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: SeongJae Park <sj@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Ryan Roberts authored
Make clear the atmicity/consistency requirements of the API and how we achieve them. Link: https://lore.kernel.org/linux-mm/Zc-Tqqfksho3BHmU@arm.com/ Link: https://lkml.kernel.org/r/20240226120321.1055731-3-ryan.roberts@arm.comSigned-off-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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Ryan Roberts authored
Patch series "Address some contpte nits". These 2 patches address some nits raised by Catalin late in the review cycle for my contpte series [1]. [1] https://lore.kernel.org/linux-mm/20240215103205.2607016-1-ryan.roberts@arm.com/ This patch (of 2): The contpte symbols must be exported since some of the public inline ptep_* APIs are called from modules and these inlines now call the contpte functions. Originally they were exported as EXPORT_SYMBOL() for fear of breaking out-of-tree modules. But we subsequently concluded that EXPORT_SYMBOL_GPL() should be safe since these functions are deeply core mm routines, and any module operating at this level is not going to be able to survive on EXPORT_SYMBOL alone. Link: https://lkml.kernel.org/r/20240226120321.1055731-1-ryan.roberts@arm.com Link: https://lore.kernel.org/linux-mm/f9fc2b31-11cb-4969-8961-9c89fea41b74@nvidia.com/ Link: https://lkml.kernel.org/r/20240226120321.1055731-2-ryan.roberts@arm.comSigned-off-by:
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Barry Song authored
The doc needs a fix. As only in the case of virtual address, we are calling madvise() with MADV_PAGEOUT. But in the case of physical address, we are calling reclaim_pages() directly. MADV_PAGEOUT on virtual address is much more aggresive to reclaim memory compared to reclaim_pages() on paddr region. This patch removes the details so that the description can apply to both cases. And we don't need to couple with the implementation details. Link: https://lkml.kernel.org/r/20240224224751.4673-1-21cnbao@gmail.comSigned-off-by:
SeongJae Park <sj@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Paul Heidekrüger authored
Address the additional feedback since 4e76c8cc kasan: add atomic tests (""kasan: add atomic tests") by removing an explicit cast and fixing the size as well as the check of the allocation of `a2`. Link: https://lkml.kernel.org/r/20240224105414.211995-1-paul.heidekrueger@tum.de Link: https://lore.kernel.org/all/20240131210041.686657-1-paul.heidekrueger@tum.de/T/#u Fixes: 4e76c8cc ("kasan: add atomic tests") Signed-off-by:
Paul Heidekrüger <paul.heidekrueger@tum.de> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=214055Reviewed-by:
Marco Elver <elver@google.com> Tested-by:
Mark Rutland <mark.rutland@arm.com> Reviewed-by:
Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by:
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Dan Carpenter authored
The stack_pools[] array has DEPOT_MAX_POOLS. The "pools_num" tracks the number of pools which are initialized. See depot_init_pool() for more details. If pool_index == pools_num_cached, this will read one element beyond what we want. If not all the pools are initialized, then the pool will be NULL, triggering a WARN(), and if they are all initialized it will read one element beyond the end of the array. Link: https://lkml.kernel.org/r/361ac881-60b7-471f-91e5-5bf8fe8042b2@moroto.mountain Fixes: b29d3188 ("lib/stackdepot: store free stack records in a freelist") Signed-off-by:
Dan Carpenter <dan.carpenter@linaro.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by:
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Kefeng Wang authored
The zcomp_set_max_streams() is removed from commit 43209ea2 ("zram: remove max_comp_streams internals"), remove the declaration. Link: https://lkml.kernel.org/r/20240223035548.2591882-2-wangkefeng.wang@huawei.comSigned-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by:
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Carlos Galo authored
The current implementation of the mark_victim tracepoint provides only the process ID (pid) of the victim process. This limitation poses challenges for userspace tools requiring real-time OOM analysis and intervention. Although this information is available from the kernel logs, it’s not the appropriate format to provide OOM notifications. In Android, BPF programs are used with the mark_victim trace events to notify userspace of an OOM kill. For consistency, update the trace event to include the same information about the OOMed victim as the kernel logs. - UID In Android each installed application has a unique UID. Including the `uid` assists in correlating OOM events with specific apps. - Process Name (comm) Enables identification of the affected process. - OOM Score Will allow userspace to get additional insight of the relative kill priority of the OOM victim. In Android, the oom_score_adj is used to categorize app state (foreground, background, etc.), which aids in analyzing user-perceptible impacts of OOM events [1]. - Total VM, RSS Stats, and pgtables Amount of memory used by the victim that will, potentially, be freed up by killing it. [1] https://cs.android.com/android/platform/superproject/main/+/246dc8fc95b6d93afcba5c6d6c133307abb3ac2e:frameworks/base/services/core/java/com/android/server/am/ProcessList.java;l=188-283Signed-off-by:
Carlos Galo <carlosgalo@google.com> Reviewed-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
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Javier Carrasco authored
This binary is missing in the .gitignore and stays as an untracked file. Link: https://lore.kernel.org/r/20240214-damon_selftest_gitignore-v1-1-f517d0f9f783@gmail.com Link: https://lkml.kernel.org/r/20240221211148.46522-3-sj@kernel.orgSigned-off-by:
Javier Carrasco <javier.carrasco.cruz@gmail.com> Singed-off-by:
Bernd Edlinger <bernd.edlinger@hotmail.de> Closes: https://lore.kernel.org/all/AS8P193MB1285C963658008F1B2702AF7E4792@AS8P193MB1285.EURP193.PROD.OUTLOOK.COM/Reviewed-by:
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Vincenzo Mezzela authored
Patch series "selftests/damon: misc fixes". Misc fixes for DAMON selftets on behalf of the original authors. This patch (of 2): This patch resolves a spelling error in the test log, preventing potential confusion. It is submitted as part of my application to the "Linux Kernel Bug Fixing Spring Unpaid 2024" mentorship program of the Linux Foundation. Link: https://lore.kernel.org/r/20240204122523.14160-1-vincenzo.mezzela@gmail.com Link: https://lkml.kernel.org/r/20240221211148.46522-2-sj@kernel.orgSigned-off-by:
Vincenzo Mezzela <vincenzo.mezzela@gmail.com> Signed-off-by:
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Vishal Moola (Oracle) authored
Hugetlb can now safely handle faults under the VMA lock, so allow it to do so. This patch may cause ltp hugemmap10 to "fail". Hugemmap10 tests hugetlb counters, and expects the counters to remain unchanged on failure to handle a fault. In hugetlb_no_page(), vmf_anon_prepare() may bailout with no anon_vma under the VMA lock after allocating a folio for the hugepage. In free_huge_folio(), this folio is completely freed on bailout iff there is a surplus of hugetlb pages. This will remove a folio off the freelist and decrement the number of hugepages while ltp expects these counters to remain unchanged on failure. Originally this could only happen due to OOM failures, but now it may also occur after we allocate a hugetlb folio without a suitable anon_vma under the VMA lock. This should only happen for the first freshly allocated hugepage in this vma. Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.comSigned-off-by:
Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by:
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Vishal Moola (Oracle) authored
hugetlb_no_page() and hugetlb_wp() call anon_vma_prepare(). In preparation for hugetlb to safely handle faults under the VMA lock, use vmf_anon_prepare() here instead. Additionally, passing hugetlb_wp() the vm_fault struct from hugetlb_fault() works toward cleaning up the hugetlb code and function stack. Link: https://lkml.kernel.org/r/20240221234732.187629-5-vishal.moola@gmail.comSigned-off-by:
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Vishal Moola (Oracle) authored
Now that hugetlb_fault() has a struct vm_fault, have hugetlb_handle_userfault() use it instead of creating one of its own. This lets us reduce the number of arguments passed to hugetlb_handle_userfault() from 7 to 3, cleaning up the code and stack. Link: https://lkml.kernel.org/r/20240221234732.187629-4-vishal.moola@gmail.comSigned-off-by:
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Vishal Moola (Oracle) authored
hugetlb_fault() currently defines a vm_fault to pass to the generic handle_userfault() function. We can move this definition to the top of hugetlb_fault() so that it can be used throughout the rest of the hugetlb fault path. This will help cleanup a number of excess variables and function arguments throughout the stack. Also, since vm_fault already has space to store the page offset, use that instead and get rid of idx. Link: https://lkml.kernel.org/r/20240221234732.187629-3-vishal.moola@gmail.comSigned-off-by:
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Vishal Moola (Oracle) authored
Patch series "Handle hugetlb faults under the VMA lock", v2. It is generally safe to handle hugetlb faults under the VMA lock. The only time this is unsafe is when no anon_vma has been allocated to this vma yet, so we can use vmf_anon_prepare() instead of anon_vma_prepare() to bailout if necessary. This should only happen for the first hugetlb page in the vma. Additionally, this patchset begins to use struct vm_fault within hugetlb_fault(). This works towards cleaning up hugetlb code, and should significantly reduce the number of arguments passed to functions. The last patch in this series may cause ltp hugemmap10 to "fail". This is because vmf_anon_prepare() may bailout with no anon_vma under the VMA lock after allocating a folio for the hugepage. In free_huge_folio(), this folio is completely freed on bailout iff there is a surplus of hugetlb pages. This will remove a folio off the freelist and decrement the number of hugepages while ltp expects these counters to remain unchanged on failure. The rest of the ltp testcases pass. This patch (of 2): In order to handle hugetlb faults under the VMA lock, hugetlb can use vmf_anon_prepare() to ensure we can safely prepare an anon_vma. Change it to be a non-static function so it can be used within hugetlb as well. Link: https://lkml.kernel.org/r/20240221234732.187629-6-vishal.moola@gmail.com Link: https://lkml.kernel.org/r/20240221234732.187629-2-vishal.moola@gmail.comSigned-off-by:
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