- 26 Jan, 2024 22 commits
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Ryan Roberts authored
The addition of commit efa7df3e ("mm: align larger anonymous mappings on THP boundaries") caused the "virtual_address_range" mm selftest to start failing on arm64. Let's fix that regression. There were 2 visible problems when running the test; 1) it takes much longer to execute, and 2) the test fails. Both are related: The (first part of the) test allocates as many 1GB anonymous blocks as it can in the low 256TB of address space, passing NULL as the addr hint to mmap. Before the faulty patch, all allocations were abutted and contained in a single, merged VMA. However, after this patch, each allocation is in its own VMA, and there is a 2M gap between each VMA. This causes the 2 problems in the test: 1) mmap becomes MUCH slower because there are so many VMAs to check to find a new 1G gap. 2) mmap fails once it hits the VMA limit (/proc/sys/vm/max_map_count). Hitting this limit then causes a subsequent calloc() to fail, which causes the test to fail. The problem is that arm64 (unlike x86) selects ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT. But __thp_get_unmapped_area() allocates len+2M then always aligns to the bottom of the discovered gap. That causes the 2M hole. Fix this by detecting cases where we can still achive the alignment goal when moved to the top of the allocated area, if configured to prefer top-down allocation. While we are at it, fix thp_get_unmapped_area's use of pgoff, which should always be zero for anonymous mappings. Prior to the faulty change, while it was possible for user space to pass in pgoff!=0, the old mm->get_unmapped_area() handler would not use it. thp_get_unmapped_area() does use it, so let's explicitly zero it before calling the handler. This should also be the correct behavior for arches that define their own get_unmapped_area() handler. Link: https://lkml.kernel.org/r/20240123171420.3970220-1-ryan.roberts@arm.com Fixes: efa7df3e ("mm: align larger anonymous mappings on THP boundaries") Closes: https://lore.kernel.org/linux-mm/1e8f5ac7-54ce-433a-ae53-81522b2320e1@arm.com/Signed-off-by:
Ryan Roberts <ryan.roberts@arm.com> Reviewed-by:
Yang Shi <shy828301@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Yang Shi authored
commit efa7df3e ("mm: align larger anonymous mappings on THP boundaries") caused two issues [1] [2] reported on 32 bit system or compat userspace. It doesn't make too much sense to force huge page alignment on 32 bit system due to the constrained virtual address space. [1] https://lore.kernel.org/linux-mm/d0a136a0-4a31-46bc-adf4-2db109a61672@kernel.org/ [2] https://lore.kernel.org/linux-mm/CAJuCfpHXLdQy1a2B6xN2d7quTYwg2OoZseYPZTRpU0eHHKD-sQ@mail.gmail.com/ Link: https://lkml.kernel.org/r/20240118180505.2914778-1-shy828301@gmail.com Fixes: efa7df3e ("mm: align larger anonymous mappings on THP boundaries") Signed-off-by:
Yang Shi <yang@os.amperecomputing.com> Reported-by:
Jiri Slaby <jirislaby@kernel.org> Reported-by:
Suren Baghdasaryan <surenb@google.com> Tested-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rik van Riel <riel@surriel.com> Cc: Christopher Lameter <cl@linux.com> Signed-off-by:
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Lokesh Gidra authored
In mfill_atomic_hugetlb(), mmap_changing isn't being checked again if we drop mmap_lock and reacquire it. When the lock is not held, mmap_changing could have been incremented. This is also inconsistent with the behavior in mfill_atomic(). Link: https://lkml.kernel.org/r/20240117223729.1444522-1-lokeshgidra@google.com Fixes: df2cc96e ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Signed-off-by:
Lokesh Gidra <lokeshgidra@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Brian Geffon <bgeffon@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nicolas Geoffray <ngeoffray@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Ryan Roberts authored
ksm_tests was previously mmapping a region of memory, aligning the returned pointer to a PMD boundary, then setting MADV_HUGEPAGE, but was setting it past the end of the mmapped area due to not taking the pointer alignment into consideration. Fix this behaviour. Up until commit efa7df3e ("mm: align larger anonymous mappings on THP boundaries"), this buggy behavior was (usually) masked because the alignment difference was always less than PMD-size. But since the mentioned commit, `ksm_tests -H -s 100` started failing. Link: https://lkml.kernel.org/r/20240122120554.3108022-1-ryan.roberts@arm.com Fixes: 32525489 ("selftests: vm: add KSM huge pages merging time test") Signed-off-by:
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Samuel Holland authored
The shadow call stack implementation fails to build without CONFIG_MMU: ld.lld: error: undefined symbol: vfree_atomic >>> referenced by scs.c >>> kernel/scs.o:(scs_free) in archive vmlinux.a Link: https://lkml.kernel.org/r/20240122175204.2371009-1-samuel.holland@sifive.com Fixes: a2abe7cb ("scs: switch to vmapped shadow stacks") Signed-off-by:
Samuel Holland <samuel.holland@sifive.com> Reviewed-by:
Sami Tolvanen <samitolvanen@google.com> Cc: Will Deacon <will@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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David Hildenbrand authored
The correct folio replacement for "set_page_dirty()" is "folio_mark_dirty()", not "folio_set_dirty()". Using the latter won't properly inform the FS using the dirty_folio() callback. This has been found by code inspection, but likely this can result in some real trouble when zapping dirty PTEs that point at clean pagecache folios. Yuezhang Mo said: "Without this fix, testing the latest exfat with xfstests, test cases generic/029 and generic/030 will fail." Link: https://lkml.kernel.org/r/20240122171751.272074-1-david@redhat.com Fixes: c4626503 ("mm/memory: page_remove_rmap() -> folio_remove_rmap_pte()") Signed-off-by:
David Hildenbrand <david@redhat.com> Reported-by:
Yuezhang Mo <Yuezhang.Mo@sony.com> Signed-off-by:
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David Hildenbrand authored
The correct folio replacement for "set_page_dirty()" is "folio_mark_dirty()", not "folio_set_dirty()". Using the latter won't properly inform the FS using the dirty_folio() callback. This has been found by code inspection, but likely this can result in some real trouble. Link: https://lkml.kernel.org/r/20240122175407.307992-1-david@redhat.com Fixes: a8e61d58 ("mm/huge_memory: page_remove_rmap() -> folio_remove_rmap_pmd()") Signed-off-by:
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Audra Mitchell authored
In order for the page table level 5 to be in use, the CPU must have the setting enabled in addition to the CONFIG option. Check for the flag to be set to avoid false test failures on systems that do not have this cpu flag set. The test does a series of mmap calls including three using the MAP_FIXED flag and specifying an address that is 1<<47 or 1<<48. These addresses are only available if you are using level 5 page tables, which requires both the CPU to have the capabiltiy (la57 flag) and the kernel to be configured. Currently the test only checks for the kernel configuration option, so this test can still report a false positive. Here are the three failing lines: $ ./va_high_addr_switch | grep FAILED mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED): 0xffffffffffffffff - FAILED mmap(HIGH_ADDR, MAP_FIXED): 0xffffffffffffffff - FAILED mmap(ADDR_SWITCH_HINT, 2 * PAGE_SIZE, MAP_FIXED): 0xffffffffffffffff - FAILED I thought (for about a second) refactoring the test so that these three mmap calls will only be run on systems with the level 5 page tables available, but the whole point of the test is to check the level 5 feature... Link: https://lkml.kernel.org/r/20240119205801.62769-1-audra@redhat.com Fixes: 4f2930c6 ("selftests/vm: only run 128TBswitch with 5-level paging") Signed-off-by:
Audra Mitchell <audra@redhat.com> Cc: Rafael Aquini <raquini@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Adam Sindelar <adam@wowsignal.io> Cc: <stable@vger.kernel.org> Signed-off-by:
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Nico Pache authored
On systems with 64k page size and 512M huge page sizes, the allocation and test succeeds but errors out at the munmap. As the comment states, munmap will failure if its not HUGEPAGE aligned. This is due to the length of the mapping being 1/2 the size of the hugepage causing the munmap to not be hugepage aligned. Fix this by making the mapping length the full hugepage if the hugepage is larger than the length of the mapping. Link: https://lkml.kernel.org/r/20240119131429.172448-1-npache@redhat.comSigned-off-by:
Nico Pache <npache@redhat.com> Cc: Donet Tom <donettom@linux.vnet.ibm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Christophe Leroy <christophe.leroy@c-s.fr> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: <stable@vger.kernel.org> Signed-off-by:
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Yosry Ahmed authored
As discussed on the mailing list [1], merge the zpool maintainers entry into the zswap one. Also, add CREDITS entries for previous zswap/zpool maintainers. [1] https://lore.kernel.org/linux-mm/CAJD7tkYx4YWhGoVwnSeGc8dY_1aRRxxg8PzWBV==A6iqG_OgFw@mail.gmail.com/ Link: https://lkml.kernel.org/r/20240117182152.1439822-1-yosryahmed@google.comSigned-off-by:
Yosry Ahmed <yosryahmed@google.com> Acked-by:
Nhat Pham <nphamcs@gmail.com> Acked-by:
Dan Streetman <ddstreet@ieee.org> Acked-by:
Seth Jennings <sjenning@redhat.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by:
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Marco Elver authored
With the introduction of the pool_rwlock (reader-writer lock), several fast paths end up taking the pool_rwlock as readers. Furthermore, stack_depot_put() unconditionally takes the pool_rwlock as a writer. Despite allowing readers to make forward-progress concurrently, reader-writer locks have inherent cache contention issues, which does not scale well on systems with large CPU counts. Rework the synchronization story of stack depot to again avoid taking any locks in the fast paths. This is done by relying on RCU-protected list traversal, and the NMI-safe subset of RCU to delay reuse of freed stack records. See code comments for more details. Along with the performance issues, this also fixes incorrect nesting of rwlock within a raw_spinlock, given that stack depot should still be usable from anywhere: | [ BUG: Invalid wait context ] | ----------------------------- | swapper/0/1 is trying to lock: | ffffffff89869be8 (pool_rwlock){..--}-{3:3}, at: stack_depot_save_flags | other info that might help us debug this: | context-{5:5} | 2 locks held by swapper/0/1: | #0: ffffffff89632440 (rcu_read_lock){....}-{1:3}, at: __queue_work | #1: ffff888100092018 (&pool->lock){-.-.}-{2:2}, at: __queue_work <-- raw_spin_lock Stack depot usage stats are similar to the previous version after a KASAN kernel boot: $ cat /sys/kernel/debug/stackdepot/stats pools: 838 allocations: 29865 frees: 6604 in_use: 23261 freelist_size: 1879 The number of pools is the same as previously. The freelist size is minimally larger, but this may also be due to variance across system boots. This shows that even though we do not eagerly wait for the next RCU grace period (such as with synchronize_rcu() or call_rcu()) after freeing a stack record - requiring depot_pop_free() to "poll" if an entry may be used - new allocations are very likely to happen in later RCU grace periods. Link: https://lkml.kernel.org/r/20240118110216.2539519-2-elver@google.com Fixes: 108be8de ("lib/stackdepot: allow users to evict stack traces") Reported-by:Andi Kleen <ak@linux.intel.com> Signed-off-by:
Marco Elver <elver@google.com> Reviewed-by:
Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
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Marco Elver authored
Add a few basic stats counters for stack depot that can be used to derive if stack depot is working as intended. This is a snapshot of the new stats after booting a system with a KASAN-enabled kernel: $ cat /sys/kernel/debug/stackdepot/stats pools: 838 allocations: 29861 frees: 6561 in_use: 23300 freelist_size: 1840 Generally, "pools" should be well below the max; once the system is booted, "in_use" should remain relatively steady. Link: https://lkml.kernel.org/r/20240118110216.2539519-1-elver@google.comSigned-off-by:
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Marco Elver authored
Alexander Potapenko writes in [1]: "For every memory access in the code instrumented by KMSAN we call kmsan_get_metadata() to obtain the metadata for the memory being accessed. For virtual memory the metadata pointers are stored in the corresponding `struct page`, therefore we need to call virt_to_page() to get them. According to the comment in arch/x86/include/asm/page.h, virt_to_page(kaddr) returns a valid pointer iff virt_addr_valid(kaddr) is true, so KMSAN needs to call virt_addr_valid() as well. To avoid recursion, kmsan_get_metadata() must not call instrumented code, therefore ./arch/x86/include/asm/kmsan.h forks parts of arch/x86/mm/physaddr.c to check whether a virtual address is valid or not. But the introduction of rcu_read_lock() to pfn_valid() added instrumented RCU API calls to virt_to_page_or_null(), which is called by kmsan_get_metadata(), so there is an infinite recursion now. I do not think it is correct to stop that recursion by doing kmsan_enter_runtime()/kmsan_exit_runtime() in kmsan_get_metadata(): that would prevent instrumented functions called from within the runtime from tracking the shadow values, which might introduce false positives." Fix the issue by switching pfn_valid() to the _sched() variant of rcu_read_lock/unlock(), which does not require calling into RCU. Given the critical section in pfn_valid() is very small, this is a reasonable trade-off (with preemptible RCU). KMSAN further needs to be careful to suppress calls into the scheduler, which would be another source of recursion. This can be done by wrapping the call to pfn_valid() into preempt_disable/enable_no_resched(). The downside is that this sacrifices breaking scheduling guarantees; however, a kernel compiled with KMSAN has already given up any performance guarantees due to being heavily instrumented. Note, KMSAN code already disables tracing via Makefile, and since mmzone.h is included, it is not necessary to use the notrace variant, which is generally preferred in all other cases. Link: https://lkml.kernel.org/r/20240115184430.2710652-1-glider@google.com [1] Link: https://lkml.kernel.org/r/20240118110022.2538350-1-elver@google.com Fixes: 5ec8e8ea ("mm/sparsemem: fix race in accessing memory_section->usage") Signed-off-by:
Alexander Potapenko <glider@google.com> Reported-by: syzbot+93a9e8a3dea8d6085e12@syzkaller.appspotmail.com Reviewed-by:
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Zach O'Keefe authored
(struct dirty_throttle_control *)->thresh is an unsigned long, but is passed as the u32 divisor argument to div_u64(). On architectures where unsigned long is 64 bytes, the argument will be implicitly truncated. Use div64_u64() instead of div_u64() so that the value used in the "is this a safe division" check is the same as the divisor. Also, remove redundant cast of the numerator to u64, as that should happen implicitly. This would be difficult to exploit in memcg domain, given the ratio-based arithmetic domain_drity_limits() uses, but is much easier in global writeback domain with a BDI_CAP_STRICTLIMIT-backing device, using e.g. vm.dirty_bytes=(1<<32)*PAGE_SIZE so that dtc->thresh == (1<<32) Link: https://lkml.kernel.org/r/20240118181954.1415197-1-zokeefe@google.com Fixes: f6789593 ("mm/page-writeback.c: fix divide by zero in bdi_dirty_limits()") Signed-off-by:
Zach O'Keefe <zokeefe@google.com> Cc: Maxim Patlasov <MPatlasov@parallels.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Muhammad Usama Anjum authored
Running charge_reserved_hugetlb.sh generates errors if sh is set to dash: ./charge_reserved_hugetlb.sh: 9: [[: not found ./charge_reserved_hugetlb.sh: 19: [[: not found ./charge_reserved_hugetlb.sh: 27: [[: not found ./charge_reserved_hugetlb.sh: 37: [[: not found ./charge_reserved_hugetlb.sh: 45: Syntax error: "(" unexpected Switch to using /bin/bash instead of /bin/sh. Make the switch for write_hugetlb_memory.sh as well which is called from charge_reserved_hugetlb.sh. Link: https://lkml.kernel.org/r/20240116090455.3407378-1-usama.anjum@collabora.comSigned-off-by:Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Shuah Khan <shuah@kernel.org> Cc: David Laight <David.Laight@ACULAB.COM> Cc: <stable@vger.kernel.org> Signed-off-by:
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Petr Vorel authored
The maintainer uses both. Link: https://lkml.kernel.org/r/20240117122257.2707637-1-pvorel@suse.czSigned-off-by:
Petr Vorel <pvorel@suse.cz> Reviewed-by:
Alejandro Colomar <alx@kernel.org> Signed-off-by:
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Johannes Weiner authored
While investigating hosts with high cgroup memory pressures, Tejun found culprit zombie tasks that had were holding on to a lot of memory, had SIGKILL pending, but were stuck in memory.high reclaim. In the past, we used to always force-charge allocations from tasks that were exiting in order to accelerate them dying and freeing up their rss. This changed for memory.max in a4ebf1b6 ("memcg: prohibit unconditional exceeding the limit of dying tasks"); it noted that this can cause (userspace inducable) containment failures, so it added a mandatory reclaim and OOM kill cycle before forcing charges. At the time, memory.high enforcement was handled in the userspace return path, which isn't reached by dying tasks, and so memory.high was still never enforced by dying tasks. When c9afe31e ("memcg: synchronously enforce memory.high for large overcharges") added synchronous reclaim for memory.high, it added unconditional memory.high enforcement for dying tasks as well. The callstack shows that this path is where the zombie is stuck in. We need to accelerate dying tasks getting past memory.high, but we cannot do it quite the same way as we do for memory.max: memory.max is enforced strictly, and tasks aren't allowed to move past it without FIRST reclaiming and OOM killing if necessary. This ensures very small levels of excess. With memory.high, though, enforcement happens lazily after the charge, and OOM killing is never triggered. A lot of concurrent threads could have pushed, or could actively be pushing, the cgroup into excess. The dying task will enter reclaim on every allocation attempt, with little hope of restoring balance. To fix this, skip synchronous memory.high enforcement on dying tasks altogether again. Update memory.high path documentation while at it. [hannes@cmpxchg.org: also handle tasks are being killed during the reclaim] Link: https://lkml.kernel.org/r/20240111192807.GA424308@cmpxchg.org Link: https://lkml.kernel.org/r/20240111132902.389862-1-hannes@cmpxchg.org Fixes: c9afe31e ("memcg: synchronously enforce memory.high for large overcharges") Signed-off-by:
Tejun Heo <tj@kernel.org> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Acked-by:
Roman Gushchin <roman.gushchin@linux.dev> Cc: Dan Schatzberg <schatzberg.dan@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by:
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Yang Shi authored
commit efa7df3e ("mm: align larger anonymous mappings on THP boundaries") incured regression for stress-ng pthread benchmark [1]. It is because THP get allocated to pthread's stack area much more possible than before. Pthread's stack area is allocated by mmap without VM_GROWSDOWN or VM_GROWSUP flag, so kernel can't tell whether it is a stack area or not. The MAP_STACK flag is used to mark the stack area, but it is a no-op on Linux. Mapping MAP_STACK to VM_NOHUGEPAGE to prevent from allocating THP for such stack area. With this change the stack area looks like: fffd18e10000-fffd19610000 rw-p 00000000 00:00 0 Size: 8192 kB KernelPageSize: 4 kB MMUPageSize: 4 kB Rss: 12 kB Pss: 12 kB Pss_Dirty: 12 kB Shared_Clean: 0 kB Shared_Dirty: 0 kB Private_Clean: 0 kB Private_Dirty: 12 kB Referenced: 12 kB Anonymous: 12 kB KSM: 0 kB LazyFree: 0 kB AnonHugePages: 0 kB ShmemPmdMapped: 0 kB FilePmdMapped: 0 kB Shared_Hugetlb: 0 kB Private_Hugetlb: 0 kB Swap: 0 kB SwapPss: 0 kB Locked: 0 kB THPeligible: 0 VmFlags: rd wr mr mw me ac nh The "nh" flag is set. [1] https://lore.kernel.org/linux-mm/202312192310.56367035-oliver.sang@intel.com/ Link: https://lkml.kernel.org/r/20231221065943.2803551-2-shy828301@gmail.com Fixes: efa7df3e ("mm: align larger anonymous mappings on THP boundaries") Signed-off-by:
kernel test robot <oliver.sang@intel.com> Tested-by:
Yin Fengwei <fengwei.yin@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Christopher Lameter <cl@linux.com> Cc: Huang, Ying <ying.huang@intel.com> Cc: <stable@vger.kerenl.org> Signed-off-by:
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David Hildenbrand authored
uprobes passes an unaligned page mapping address to folio_add_new_anon_rmap(), which ends up triggering a VM_BUG_ON() we recently extended in commit 372cbd4d ("mm: non-pmd-mappable, large folios for folio_add_new_anon_rmap()"). Arguably, this is uprobes code doing something wrong; however, for the time being it would have likely worked in rmap code because __folio_set_anon() would set folio->index to the same value. Looking at __replace_page(), we'd also pass slightly wrong values to mmu_notifier_range_init(), page_vma_mapped_walk(), flush_cache_page(), ptep_clear_flush() and set_pte_at_notify(). I suspect most of them are fine, but let's just mark the introducing commit as the one needed fixing. I don't think CC stable is warranted. We'll add more sanity checks in rmap code separately, to make sure that we always get properly aligned addresses. Link: https://lkml.kernel.org/r/20240115100731.91007-1-david@redhat.com Fixes: c517ee74 ("uprobes: __replace_page() should not use page_address_in_vma()") Signed-off-by:
Jiri Olsa <jolsa@kernel.org> Closes: https://lkml.kernel.org/r/ZaMR2EWN-HvlCfUl@kravaTested-by:
Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by:
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Muhammad Usama Anjum authored
Use 2 separate variables of types int and unsigned long long instead of confusing them. This corrects the correct print format for each of them and removes the build warning: warning: format `%d' expects argument of type `int', but argument 2 has type `long long unsigned int' Link: https://lkml.kernel.org/r/20240112071851.612930-1-usama.anjum@collabora.com Fixes: a4cb3b24 ("selftests: mm: add a test for remapping to area immediately after existing mapping") Signed-off-by:
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Sidhartha Kumar authored
has_extra_refcount() makes the assumption that the page cache adds a ref count of 1 and subtracts this in the extra_pins case. Commit a08c7193 (mm/filemap: remove hugetlb special casing in filemap.c) modifies __filemap_add_folio() by calling folio_ref_add(folio, nr); for all cases (including hugtetlb) where nr is the number of pages in the folio. We should adjust the number of references coming from the page cache by subtracing the number of pages rather than 1. In hugetlbfs_read_iter(), folio_test_has_hwpoisoned() is testing the wrong flag as, in the hugetlb case, memory-failure code calls folio_test_set_hwpoison() to indicate poison. folio_test_hwpoison() is the correct function to test for that flag. After these fixes, the hugetlb hwpoison read selftest passes all cases. Link: https://lkml.kernel.org/r/20240112180840.367006-1-sidhartha.kumar@oracle.com Fixes: a08c7193 ("mm/filemap: remove hugetlb special casing in filemap.c") Signed-off-by:
Sidhartha Kumar <sidhartha.kumar@oracle.com> Closes: https://lore.kernel.org/linux-mm/20230713001833.3778937-1-jiaqiyan@google.com/T/#m8e1469119e5b831bbd05d495f96b842e4a1c5519Reported-by:
Miaohe Lin <linmiaohe@huawei.com> Acked-by:
Muchun Song <muchun.song@linux.dev> Cc: James Houghton <jthoughton@google.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: <stable@vger.kernel.org> [6.7+] Signed-off-by:
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Jan Kara authored
ra_alloc_folio() marks a page that should trigger next round of async readahead. However it rounds up computed index to the order of page being allocated. This can however lead to multiple consecutive pages being marked with readahead flag. Consider situation with index == 1, mark == 1, order == 0. We insert order 0 page at index 1 and mark it. Then we bump order to 1, index to 2, mark (still == 1) is rounded up to 2 so page at index 2 is marked as well. Then we bump order to 2, index is incremented to 4, mark gets rounded to 4 so page at index 4 is marked as well. The fact that multiple pages get marked within a single readahead window confuses the readahead logic and results in readahead window being trimmed back to 1. This situation is triggered in particular when maximum readahead window size is not a power of two (in the observed case it was 768 KB) and as a result sequential read throughput suffers. Fix the problem by rounding 'mark' down instead of up. Because the index is naturally aligned to 'order', we are guaranteed 'rounded mark' == index iff 'mark' is within the page we are allocating at 'index' and thus exactly one page is marked with readahead flag as required by the readahead code and sequential read performance is restored. This effectively reverts part of commit b9ff43dd ("mm/readahead: Fix readahead with large folios"). The commit changed the rounding with the rationale: "... we were setting the readahead flag on the folio which contains the last byte read from the block. This is wrong because we will trigger readahead at the end of the read without waiting to see if a subsequent read is going to use the pages we just read." Although this is true, the fact is this was always the case with read sizes not aligned to folio boundaries and large folios in the page cache just make the situation more obvious (and frequent). Also for sequential read workloads it is better to trigger the readahead earlier rather than later. It is true that the difference in the rounding and thus earlier triggering of the readahead can result in reading more for semi-random workloads. However workloads really suffering from this seem to be rare. In particular I have verified that the workload described in commit b9ff43dd ("mm/readahead: Fix readahead with large folios") of reading random 100k blocks from a file like: [reader] bs=100k rw=randread numjobs=1 size=64g runtime=60s is not impacted by the rounding change and achieves ~70MB/s in both cases. [jack@suse.cz: fix one more place where mark rounding was done as well] Link: https://lkml.kernel.org/r/20240123153254.5206-1-jack@suse.cz Link: https://lkml.kernel.org/r/20240104085839.21029-1-jack@suse.cz Fixes: b9ff43dd ("mm/readahead: Fix readahead with large folios") Signed-off-by:
Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Guo Xuenan <guoxuenan@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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- 23 Jan, 2024 1 commit
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Andrew Morton authored
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- 21 Jan, 2024 17 commits
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Linus Torvalds authored
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https://evilpiepirate.org/git/bcachefsLinus Torvalds authored
Pull more bcachefs updates from Kent Overstreet: "Some fixes, Some refactoring, some minor features: - Assorted prep work for disk space accounting rewrite - BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this makes our trigger context more explicit - A few fixes to avoid excessive transaction restarts on multithreaded workloads: fstests (in addition to ktest tests) are now checking slowpath counters, and that's shaking out a few bugs - Assorted tracepoint improvements - Starting to break up bcachefs_format.h and move on disk types so they're with the code they belong to; this will make room to start documenting the on disk format better. - A few minor fixes" * tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits) bcachefs: Improve inode_to_text() bcachefs: logged_ops_format.h bcachefs: reflink_format.h bcachefs; extents_format.h bcachefs: ec_format.h bcachefs: subvolume_format.h bcachefs: snapshot_format.h bcachefs: alloc_background_format.h bcachefs: xattr_format.h bcachefs: dirent_format.h bcachefs: inode_format.h bcachefs; quota_format.h bcachefs: sb-counters_format.h bcachefs: counters.c -> sb-counters.c bcachefs: comment bch_subvolume bcachefs: bch_snapshot::btime bcachefs: add missing __GFP_NOWARN bcachefs: opts->compression can now also be applied in the background bcachefs: Prep work for variable size btree node buffers bcachefs: grab s_umount only if snapshotting ... -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull timer updates from Thomas Gleixner: "Updates for time and clocksources: - A fix for the idle and iowait time accounting vs CPU hotplug. The time is reset on CPU hotplug which makes the accumulated systemwide time jump backwards. - Assorted fixes and improvements for clocksource/event drivers" * tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug clocksource/drivers/ep93xx: Fix error handling during probe clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings clocksource/timer-riscv: Add riscv_clock_shutdown callback dt-bindings: timer: Add StarFive JH8100 clint dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs -
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc fixes from Aneesh Kumar: - Increase default stack size to 32KB for Book3S Thanks to Michael Ellerman. * tag 'powerpc-6.8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64s: Increase default stack size to 32KB
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Kent Overstreet authored
Add line breaks - inode_to_text() is now much easier to read. Signed-off-by:Kent Overstreet <kent.overstreet@linux.dev>
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Kent Overstreet authored
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Kent Overstreet authored
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Kent Overstreet authored
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Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
Signed-off-by: -
Kent Overstreet authored
bcachefs_format.h has gotten too big; let's do some organizing. Signed-off-by:
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