- 18 Aug, 2023 40 commits
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ZhangPeng authored
Convert count_swpout_vm_event() to take in a folio. We can remove five implicit calls to compound_head() by taking in a folio. Link: https://lkml.kernel.org/r/20230721034451.16412-10-zhangpeng362@huawei.comSigned-off-by:
ZhangPeng <zhangpeng362@huawei.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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ZhangPeng authored
Saves one implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230721034451.16412-9-zhangpeng362@huawei.comSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by:
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ZhangPeng authored
Saves one implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230721034451.16412-8-zhangpeng362@huawei.comSigned-off-by:
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ZhangPeng authored
Saves one implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230721034451.16412-7-zhangpeng362@huawei.comSigned-off-by:
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ZhangPeng authored
Saves one implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230721034451.16412-6-zhangpeng362@huawei.comSigned-off-by:
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ZhangPeng authored
Saves two implicit call to compound_head(). Link: https://lkml.kernel.org/r/20230721034451.16412-5-zhangpeng362@huawei.comSigned-off-by:
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ZhangPeng authored
Introduce bio_first_folio_all() to return a folio, which makes it easier to use. Link: https://lkml.kernel.org/r/20230721034451.16412-4-zhangpeng362@huawei.comSigned-off-by:
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ZhangPeng authored
Nobody checks the PageError()/folio_test_error() for the page/folio in __end_swap_bio_read/write() and sio_write_complete(). Therefore, we don't need to set the error flag. Just drop it. Link: https://lkml.kernel.org/r/20230721034451.16412-3-zhangpeng362@huawei.comSigned-off-by:
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ZhangPeng authored
Patch series "Convert several functions in page_io.c to use a folio", v4. Convert several functions in page_io.c to use a folio, which can remove several implicit calls to compound_head(). This patch (of 10): The VM_BUG_ON_FOLIO in swap_readpage() ensures that the page is already !uptodate in __end_swap_bio_read() and sio_read_complete(). Just remove unneeded ClearPageUptodate(). Link: https://lkml.kernel.org/r/20230721034451.16412-1-zhangpeng362@huawei.com Link: https://lkml.kernel.org/r/20230721034451.16412-2-zhangpeng362@huawei.comSigned-off-by:
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Kemeng Shi authored
Move pageblock_end_pfn after no_set_skip_hint check to avoid unneeded pageblock_end_pfn if no_set_skip_hint is set. Link: https://lkml.kernel.org/r/20230721150957.2058634-3-shikemeng@huawei.comSigned-off-by:
Kemeng Shi <shikemeng@huawei.com> Reviewed-by:
Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Signed-off-by:
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Kemeng Shi authored
Patch series "Two minor cleanups for compaction", v2. This series contains two random cleanups for compaction. This patch (of 2): If no preferred one was not found, we will use candidate page with maximum pfn > min_pfn which is saved in high_pfn. Correct "minimum" to "maximum candidate" in comment. Link: https://lkml.kernel.org/r/20230721150957.2058634-1-shikemeng@huawei.com Link: https://lkml.kernel.org/r/20230721150957.2058634-2-shikemeng@huawei.comSigned-off-by:
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Miaohe Lin authored
Since commit 79a1971c ("mm: move the copy_one_pte() pte_present check into the caller"), the explanation of preserving soft-dirtiness is moved into copy_nonpresent_pte(). Update corresponding comment. Link: https://lkml.kernel.org/r/20230723033114.3224409-1-linmiaohe@huawei.comSigned-off-by:
Miaohe Lin <linmiaohe@huawei.com> Reviewed-by:
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Ryan Roberts authored
It is very unclear to me how one is supposed to run all the mm selftests consistently and get clear results. Most of the test programs are launched by both run_vmtests.sh and run_kselftest.sh: hugepage-mmap hugepage-shm map_hugetlb hugepage-mremap hugepage-vmemmap hugetlb-madvise map_fixed_noreplace gup_test gup_longterm uffd-unit-tests uffd-stress compaction_test on-fault-limit map_populate mlock-random-test mlock2-tests mrelease_test mremap_test thuge-gen virtual_address_range va_high_addr_switch mremap_dontunmap hmm-tests madv_populate memfd_secret ksm_tests ksm_functional_tests soft-dirty cow However, of this set, when launched by run_vmtests.sh, some of the programs are invoked multiple times with different arguments. When invoked by run_kselftest.sh, they are invoked without arguments (and as a consequence, some fail immediately). Some test programs are only launched by run_vmtests.sh: test_vmalloc.sh And some test programs and only launched by run_kselftest.sh: khugepaged migration mkdirty transhuge-stress split_huge_page_test mdwe_test write_to_hugetlbfs Furthermore, run_vmtests.sh is invoked by run_kselftest.sh, so in this case all the test programs invoked by both scripts are run twice! Needless to say, this is a bit of a mess. In the absence of fully understanding the history here, it looks to me like the best solution is to launch ALL test programs from run_vmtests.sh, and ONLY invoke run_vmtests.sh from run_kselftest.sh. This way, we get full control over the parameters, each program is only invoked the intended number of times, and regardless of which script is used, the same tests get run in the same way. The only drawback is that if using run_kselftest.sh, it's top-level tap result reporting reports only a single test and it fails if any of the contained tests fail. I don't see this as a big deal though since we still see all the nested reporting from multiple layers. The other issue with this is that all of run_vmtests.sh must execute within a single kselftest timeout period, so let's increase that to something more suitable. In the Makefile, TEST_GEN_PROGS will compile and install the tests and will add them to the list of tests that run_kselftest.sh will run. TEST_GEN_FILES will compile and install the tests but will not add them to the test list. So let's move all the programs from TEST_GEN_PROGS to TEST_GEN_FILES so that they are built but not executed by run_kselftest.sh. Note that run_vmtests.sh is added to TEST_PROGS, which means it ends up in the test list. (the lack of "_GEN" means it won't be compiled, but simply copied). Link: https://lkml.kernel.org/r/20230724082522.1202616-9-ryan.roberts@arm.comSigned-off-by:
Ryan Roberts <ryan.roberts@arm.com> Acked-by:
Peter Xu <peterx@redhat.com> Cc: Florent Revest <revest@chromium.org> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mark Brown <broonie@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
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Ryan Roberts authored
Until now, transhuge-stress runs until its explicitly killed, so when invoked by run_kselftest.sh, it would run until the test timeout, then it would be killed and the test would be marked as failed. Add a new, optional command line parameter that allows the user to specify the duration in seconds that the program should run. The program exits after this duration with a success (0) exit code. If the argument is omitted the old behacvior remains. On it's own, this doesn't quite solve our problem because run_kselftest.sh does not allow passing parameters to the program under test. But we will shortly move this to run_vmtests.sh, which does allow parameter passing. Link: https://lkml.kernel.org/r/20230724082522.1202616-8-ryan.roberts@arm.comSigned-off-by:
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Ryan Roberts authored
The `migration` test currently has a number of robustness problems that cause it to hang and leak resources. Timeout: There are 3 tests, which each previously ran for 60 seconds. However, the timeout in mm/settings for a single test binary was set to 45 seconds. So when run using run_kselftest.sh, the top level timeout would trigger before the test binary was finished. Solve this by meeting in the middle; each of the 3 tests now runs for 20 seconds (for a total of 60), and the top level timeout is set to 90 seconds. Leaking child processes: the `shared_anon` test fork()s some children but then an ASSERT() fires before the test kills those children. The assert causes immediate exit of the parent and leaking of the children. Furthermore, if run using the run_kselftest.sh wrapper, the wrapper would get stuck waiting for those children to exit, which never happens. Solve this by setting the "parent death signal" to SIGHUP in the child, so that the child is killed automatically if the parent dies. With these changes, the test binary now runs to completion on arm64, with 2 tests passing and the `shared_anon` test failing. Link: https://lkml.kernel.org/r/20230724082522.1202616-7-ryan.roberts@arm.comSigned-off-by:
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Ryan Roberts authored
va_high_addr_switch has a mechanism to determine if the tests should be run or skipped (supported_arch()). This currently returns unconditionally true for arm64. However, va_high_addr_switch also requires a large virtual address space for the tests to run, otherwise they spuriously fail. Since arm64 can only support VA > 48 bits when the page size is 64K, let's decide whether we should skip the test suite based on the page size. This reduces noise when running on 4K and 16K kernels. Link: https://lkml.kernel.org/r/20230724082522.1202616-6-ryan.roberts@arm.comSigned-off-by:
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Ryan Roberts authored
thuge-gen was previously only munmapping part of the mmapped buffer, which caused us to run out of 1G huge pages for a later part of the test. Fix this by munmapping the whole buffer. Based on the code, it looks like a typo rather than an intention to keep some of the buffer mapped. thuge-gen was also calling mmap with SHM_HUGETLB flag (bit 11 set), which is actually MAP_DENYWRITE in mmap context. The man page says this flag is ignored in modern kernels. I'm pretty sure from the context that the author intended to pass the MAP_HUGETLB flag so I've fixed that up too. Link: https://lkml.kernel.org/r/20230724082522.1202616-5-ryan.roberts@arm.comSigned-off-by:
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Ryan Roberts authored
mrelease_test defaults to defining __NR_pidfd_open and __NR_process_mrelease syscall numbers to -1, if they are not defined anywhere else, and the suite would then be marked as skipped as a result. arm64 (at least the stock debian toolchain that I'm using) requires including <sys/syscall.h> to pull in the defines for these syscalls. So let's add this header. With this in place, the test is passing on arm64. Link: https://lkml.kernel.org/r/20230724082522.1202616-4-ryan.roberts@arm.comSigned-off-by:
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Ryan Roberts authored
arm64 does not support the soft-dirty PTE bit. However, the `soft-dirty` test suite is currently run unconditionally and therefore generates spurious test failures on arm64. There are also some tests in `madv_populate` which assume it is supported. For `soft-dirty` lets disable the whole suite for arm64; it is no longer built and run_vmtests.sh will skip it if its not present. For `madv_populate`, we need a runtime mechanism so that the remaining tests continue to be run. Unfortunately, the only way to determine if the soft-dirty dirty bit is supported is to write to a page, then see if the bit is set in /proc/self/pagemap. But the tests that we want to conditionally execute are testing precicesly this. So if we introduced this feature check, we could accedentally turn a real failure (on a system that claims to support soft-dirty) into a skip. So instead, do the check based on architecture; for arm64, we report that soft-dirty is not supported. Link: https://lkml.kernel.org/r/20230724082522.1202616-3-ryan.roberts@arm.comSigned-off-by:
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Ryan Roberts authored
Patch series "selftests/mm fixes for arm64", v3. Given my on-going work on large anon folios and contpte mappings, I decided it would be a good idea to start running mm selftests to help guard against regressions. However, it soon became clear that I couldn't get the suite to run cleanly on arm64 with a vanilla v6.5-rc1 kernel (perhaps I'm just doing it wrong??), so got stuck in a rabbit hole trying to debug and fix all the issues. Some were down to misconfigurations, but I also found a number of issues with the tests and even a couple of issues with the kernel. This patch (of 8): The selftests runner pipes the test program's stdout to tap_prefix. The presence of the pipe means that the test program sets its stdout to be fully buffered (as aposed to line buffered when directly connected to the terminal). The block buffering means that there is often content in the buffer at fork() time, which causes the output to end up duplicated. This was causing problems for mm:cow where test results were duplicated 20-30x. Solve this by using `stdbuf`, when available to force the test program to use line buffered mode. This means previously printf'ed results are flushed out of the program before any fork(). Additionally, explicitly set line buffer mode in ksft_print_header(), which means that all test programs that use the ksft framework will benefit even if stdbuf is not present on the system. [ryan.roberts@arm.com: add setvbuf() to set buffering mode] Link: https://lkml.kernel.org/r/20230726070655.2713530-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20230724082522.1202616-1-ryan.roberts@arm.com Link: https://lkml.kernel.org/r/20230724082522.1202616-2-ryan.roberts@arm.comSigned-off-by:
Mark Brown <broonie@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Florent Revest <revest@chromium.org> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by:
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Miaohe Lin authored
Since commit 04013513 ("mm, page_alloc: do not rely on the order of page_poison and init_on_alloc/free parameters"), init_debug_pagealloc() is converted to init_mem_debugging_and_hardening(). Later it's renamed to mem_debugging_and_hardening_init() via commit f2fc4b44 ("mm: move init_mem_debugging_and_hardening() to mm/mm_init.c"). Link: https://lkml.kernel.org/r/20230720112806.3851893-1-linmiaohe@huawei.comSigned-off-by:
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Alistair Popple authored
There are two main use cases for mmu notifiers. One is by KVM which uses mmu_notifier_invalidate_range_start()/end() to manage a software TLB. The other is to manage hardware TLBs which need to use the invalidate_range() callback because HW can establish new TLB entries at any time. Hence using start/end() can lead to memory corruption as these callbacks happen too soon/late during page unmap. mmu notifier users should therefore either use the start()/end() callbacks or the invalidate_range() callbacks. To make this usage clearer rename the invalidate_range() callback to arch_invalidate_secondary_tlbs() and update documention. Link: https://lkml.kernel.org/r/6f77248cd25545c8020a54b4e567e8b72be4dca1.1690292440.git-series.apopple@nvidia.comSigned-off-by:
Alistair Popple <apopple@nvidia.com> Suggested-by:
Jason Gunthorpe <jgg@nvidia.com> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Reviewed-by:
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Alistair Popple authored
Secondary TLBs are now invalidated from the architecture specific TLB invalidation functions. Therefore there is no need to explicitly notify or invalidate as part of the range end functions. This means we can remove mmu_notifier_invalidate_range_end_only() and some of the ptep_*_notify() functions. Link: https://lkml.kernel.org/r/90d749d03cbab256ca0edeb5287069599566d783.1690292440.git-series.apopple@nvidia.comSigned-off-by:
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Alistair Popple authored
The invalidate_range() is going to become an architecture specific mmu notifier used to keep the TLB of secondary MMUs such as an IOMMU in sync with the CPU page tables. Currently it is called from separate code paths to the main CPU TLB invalidations. This can lead to a secondary TLB not getting invalidated when required and makes it hard to reason about when exactly the secondary TLB is invalidated. To fix this move the notifier call to the architecture specific TLB maintenance functions for architectures that have secondary MMUs requiring explicit software invalidations. This fixes a SMMU bug on ARM64. On ARM64 PTE permission upgrades require a TLB invalidation. This invalidation is done by the architecture specific ptep_set_access_flags() which calls flush_tlb_page() if required. However this doesn't call the notifier resulting in infinite faults being generated by devices using the SMMU if it has previously cached a read-only PTE in it's TLB. Moving the invalidations into the TLB invalidation functions ensures all invalidations happen at the same time as the CPU invalidation. The architecture specific flush_tlb_all() routines do not call the notifier as none of the IOMMUs require this. Link: https://lkml.kernel.org/r/0287ae32d91393a582897d6c4db6f7456b1001f2.1690292440.git-series.apopple@nvidia.comSigned-off-by:
Jason Gunthorpe <jgg@ziepe.ca> Tested-by:
SeongJae Park <sj@kernel.org> Acked-by:
Luis Chamberlain <mcgrof@kernel.org> Cc: Andrew Donnellan <ajd@linux.ibm.com> Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com> Cc: Frederic Barrat <fbarrat@linux.ibm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kevin Tian <kevin.tian@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Nicolin Chen <nicolinc@nvidia.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Zhi Wang <zhi.wang.linux@gmail.com> Signed-off-by:
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Alistair Popple authored
The comment in mmu_interval_read_begin() refers to a function that doesn't exist and uses the wrong call-back name. The op for mmu interval notifiers is mmu_interval_notifier_ops->invalidate() so fix the comment up to reflect that. Link: https://lkml.kernel.org/r/e7a09081b3ac82a03c189409f1262fc2df91071e.1690292440.git-series.apopple@nvidia.comSigned-off-by:
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Alistair Popple authored
Patch series "Invalidate secondary IOMMU TLB on permission upgrade", v4. The main change is to move secondary TLB invalidation mmu notifier callbacks into the architecture specific TLB flushing functions. This makes secondary TLB invalidation mostly match CPU invalidation while still allowing efficient range based invalidations based on the existing TLB batching code. This patch (of 5): The ARM SMMU has a specific command for invalidating the TLB for an entire ASID. Currently this is used for the IO_PGTABLE API but not for ATS when called from the MMU notifier. The current implementation of notifiers does not attempt to invalidate such a large address range, instead walking each VMA and invalidating each range individually during mmap removal. However in future SMMU TLB invalidations are going to be sent as part of the normal flush_tlb_*() kernel calls. To better deal with that add handling to use TLBI ASID when invalidating the entire address space. Link: https://lkml.kernel.org/r/cover.1eca029b8603ef4eebe5b41eae51facfc5920c41.1690292440.git-series.apopple@nvidia.com Link: https://lkml.kernel.org/r/ba5f0ec5fbc2ab188797524d3687e075e2412a2b.1690292440.git-series.apopple@nvidia.comSigned-off-by:
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Liam R. Howlett authored
Use lockdep to check the write path in the maple tree holds the lock in write mode. Introduce mt_write_lock_is_held() to check if the lock is held for writing. Update the necessary checks for rcu_dereference_protected() to use the new write lock check. Link: https://lkml.kernel.org/r/20230714195551.894800-5-Liam.Howlett@oracle.comSigned-off-by:
Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oliver Sang <oliver.sang@intel.com> Signed-off-by:
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Liam R. Howlett authored
Don't set the lock to the mm lock so that the detached VMA tree does not complain about being unlocked when the mmap_lock is dropped prior to freeing the tree. Introduce mt_on_stack() for setting the external lock to NULL only when LOCKDEP is used. Move the destroying of the detached tree outside the mmap lock all together. Link: https://lkml.kernel.org/r/20230719183142.ktgcmuj2pnlr3h3s@revolverSigned-off-by:
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Liam R. Howlett authored
To support early release of the maple tree locks, do not lockdep check the lock if it is set to NULL. This is intended for the special case on-stack use of tracking entries and not for general use. Link: https://lkml.kernel.org/r/20230714195551.894800-3-Liam.Howlett@oracle.comSigned-off-by:
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Liam R. Howlett authored
Patch series "More strict maple tree lockdep", v2. Linus asked for more strict maple tree lockdep checking [1] and for them to resume the normal path through Andrews tree. This series of patches adds checks to ensure the lock is held in write mode during the write path of the maple tree instead of checking if it's held at all. It also reduces the validate_mm() calls by consolidating into commonly used functions (patch 0001), and removes the necessity of holding the lock on the detached tree during munmap() operations. This patch (of 4): validate_mm() calls are too spread out and duplicated in numerous locations. Also, now that the stack write is done under the write lock, it is not necessary to validate the mm prior to write operations. Add a validate_mm() to the stack expansions, and to vma_complete() so that numerous others may be dropped. Note that vma_link() (and also insert_vm_struct() by call path) already call validate_mm(). vma_merge() also had an unnecessary call to vma_iter_free() since the logic change to abort earlier if no merging is necessary. Drop extra validate_mm() calls at the start of functions and error paths which won't write to the tree. Relocate the validate_mm() call in the do_brk_flags() to avoid re-running the same test when vma_complete() is used. The call within the error path of mmap_region() is left intentionally because of the complexity of the function and the potential of drivers modifying the tree. Link: https://lkml.kernel.org/r/20230714195551.894800-1-Liam.Howlett@oracle.com Link: https://lkml.kernel.org/r/20230714195551.894800-2-Liam.Howlett@oracle.comSigned-off-by:
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Sidhartha Kumar authored
Convert the last page_hstate() user to use folio_hstate() so page_hstate() can be safely removed. Link: https://lkml.kernel.org/r/20230719184145.301911-1-sidhartha.kumar@oracle.comSigned-off-by:
Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <songmuchun@bytedance.com> Signed-off-by:
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Kemeng Shi authored
1. update page to folio in comment 2. add comment of new added @locked Link: https://lkml.kernel.org/r/20230718092136.1935789-1-shikemeng@huaweicloud.comSigned-off-by:
Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by:
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Peng Zhang authored
kfence_metadata is currently a static array. For the purpose of allocating scalable __kfence_pool, we first change it to runtime allocation of metadata. Since the size of an object of kfence_metadata is 1160 bytes, we can save at least 72 pages (with default 256 objects) without enabling kfence. [akpm@linux-foundation.org: restore newline, per Marco] Link: https://lkml.kernel.org/r/20230718073019.52513-1-zhangpeng.00@bytedance.comSigned-off-by:
Peng Zhang <zhangpeng.00@bytedance.com> Reviewed-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by:
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Miaohe Lin authored
Use helper macro __ATTR_RW to define numa demotion attributes. Minor readability improvement. Link: https://lkml.kernel.org/r/20230715035111.2656784-1-linmiaohe@huawei.comSigned-off-by:
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Mike Rapoport (IBM) authored
Replace FGP_FLAGS with GFP_FLAGS Link: https://lkml.kernel.org/r/20230715084038.987955-1-rppt@kernel.orgSigned-off-by:
Mike Rapoport (IBM) <rppt@kernel.org> Reviewed-by:
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Mike Rapoport (IBM) authored
Replace "Insert and entry at a give index" with "Insert an entry at a given index" Link: https://lkml.kernel.org/r/20230715143920.994812-1-rppt@kernel.orgSigned-off-by:
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Zhu, Lipeng authored
When running UnixBench/Shell Scripts, we observed high false sharing for accessing i_mmap against i_mmap_rwsem. UnixBench/Shell Scripts are typical load/execute command test scenarios, which concurrently launch->execute->exit a lot of shell commands. A lot of processes invoke vma_interval_tree_remove which touch "i_mmap", the call stack: ----vma_interval_tree_remove |----unlink_file_vma | free_pgtables | |----exit_mmap | | mmput | | |----begin_new_exec | | | load_elf_binary | | | bprm_execve Meanwhile, there are a lot of processes touch 'i_mmap_rwsem' to acquire the semaphore in order to access 'i_mmap'. In existing 'address_space' layout, 'i_mmap' and 'i_mmap_rwsem' are in the same cacheline. The patch places the i_mmap and i_mmap_rwsem in separate cache lines to avoid this false sharing problem. With this patch, based on kernel v6.4.0, on Intel Sapphire Rapids 112C/224T platform, the score improves by ~5.3%. And perf c2c tool shows the false sharing is resolved as expected, the symbol vma_interval_tree_remove disappeared in cache line 0 after this change. Baseline: ================================================= Shared Cache Line Distribution Pareto ================================================= ------------------------------------------------------------- 0 3729 5791 0 0 0xff19b3818445c740 ------------------------------------------------------------- 3.27% 3.02% 0.00% 0.00% 0x18 0 1 0xffffffffa194403b 604 483 389 692 203 [k] vma_interval_tree_insert [kernel.kallsyms] vma_interval_tree_insert+75 0 1 4.13% 3.63% 0.00% 0.00% 0x20 0 1 0xffffffffa19440a2 553 413 415 962 215 [k] vma_interval_tree_remove [kernel.kallsyms] vma_interval_tree_remove+18 0 1 2.04% 1.35% 0.00% 0.00% 0x28 0 1 0xffffffffa219a1d6 1210 855 460 1229 222 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+678 0 1 0.62% 1.85% 0.00% 0.00% 0x28 0 1 0xffffffffa219a1bf 762 329 577 527 198 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+655 0 1 0.48% 0.31% 0.00% 0.00% 0x28 0 1 0xffffffffa219a58c 1677 1476 733 1544 224 [k] down_write [kernel.kallsyms] down_write+28 0 1 0.05% 0.07% 0.00% 0.00% 0x28 0 1 0xffffffffa219a21d 1040 819 689 33 27 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+749 0 1 0.00% 0.05% 0.00% 0.00% 0x28 0 1 0xffffffffa17707db 0 1005 786 1373 223 [k] up_write [kernel.kallsyms] up_write+27 0 1 0.00% 0.02% 0.00% 0.00% 0x28 0 1 0xffffffffa219a064 0 233 778 32 30 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+308 0 1 33.82% 34.10% 0.00% 0.00% 0x30 0 1 0xffffffffa1770945 779 495 534 6011 224 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+53 0 1 17.06% 15.28% 0.00% 0.00% 0x30 0 1 0xffffffffa1770915 593 438 468 2715 224 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+5 0 1 3.54% 3.52% 0.00% 0.00% 0x30 0 1 0xffffffffa2199f84 881 601 583 1421 223 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+84 0 1 With this change: ------------------------------------------------------------- 0 556 838 0 0 0xff2780d7965d2780 ------------------------------------------------------------- 0.18% 0.60% 0.00% 0.00% 0x8 0 1 0xffffffffafff27b8 503 453 569 14 13 [k] do_dentry_open [kernel.kallsyms] do_dentry_open+456 0 1 0.54% 0.12% 0.00% 0.00% 0x8 0 1 0xffffffffaffc51ac 510 199 428 15 12 [k] hugepage_vma_check [kernel.kallsyms] hugepage_vma_check+252 0 1 1.80% 2.15% 0.00% 0.00% 0x18 0 1 0xffffffffb079a1d6 1778 799 343 215 136 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+678 0 1 0.54% 1.31% 0.00% 0.00% 0x18 0 1 0xffffffffb079a1bf 547 296 528 91 71 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+655 0 1 0.72% 0.72% 0.00% 0.00% 0x18 0 1 0xffffffffb079a58c 1479 1534 676 288 163 [k] down_write [kernel.kallsyms] down_write+28 0 1 0.00% 0.12% 0.00% 0.00% 0x18 0 1 0xffffffffafd707db 0 2381 744 282 158 [k] up_write [kernel.kallsyms] up_write+27 0 1 0.00% 0.12% 0.00% 0.00% 0x18 0 1 0xffffffffb079a064 0 239 518 6 6 [k] rwsem_down_write_slowpath [kernel.kallsyms] rwsem_down_write_slowpath+308 0 1 46.58% 47.02% 0.00% 0.00% 0x20 0 1 0xffffffffafd70945 704 403 499 1137 219 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+53 0 1 23.92% 25.78% 0.00% 0.00% 0x20 0 1 0xffffffffafd70915 558 413 500 542 185 [k] rwsem_spin_on_owner [kernel.kallsyms] rwsem_spin_on_owner+5 0 1 v1->v2: change padding to exchange fields. Link: https://lkml.kernel.org/r/20230716145653.20122-1-lipeng.zhu@intel.comSigned-off-by:Lipeng Zhu <lipeng.zhu@intel.com> Reviewed-by:
Tim Chen <tim.c.chen@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Yu Ma <yu.ma@intel.com> Signed-off-by:
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Haifeng Xu authored
node_start_pfn is not used in adjust_zone_range_for_zone_movable(), so it is pointless to waste a function argument. Drop the parameter. Link: https://lkml.kernel.org/r/20230717065811.1262-1-haifeng.xu@shopee.comSigned-off-by:
Haifeng Xu <haifeng.xu@shopee.com> Reviewed-by:
Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
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Miaohe Lin authored
When pagetable lock is held, the page will always be page_mapped(). So remove unneeded page_mapped() check. Also the page can't be freed from under us in this case. So use get_page() to get extra page reference to simplify the code. No functional change intended. Link: https://lkml.kernel.org/r/20230717113644.3026478-1-linmiaohe@huawei.comSigned-off-by:
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Barry Song authored
On x86, batched and deferred tlb shootdown has lead to 90% performance increase on tlb shootdown. on arm64, HW can do tlb shootdown without software IPI. But sync tlbi is still quite expensive. Even running a simplest program which requires swapout can prove this is true, #include <sys/types.h> #include <unistd.h> #include <sys/mman.h> #include <string.h> int main() { #define SIZE (1 * 1024 * 1024) volatile unsigned char *p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); memset(p, 0x88, SIZE); for (int k = 0; k < 10000; k++) { /* swap in */ for (int i = 0; i < SIZE; i += 4096) { (void)p[i]; } /* swap out */ madvise(p, SIZE, MADV_PAGEOUT); } } Perf result on snapdragon 888 with 8 cores by using zRAM as the swap block device. ~ # perf record taskset -c 4 ./a.out [ perf record: Woken up 10 times to write data ] [ perf record: Captured and wrote 2.297 MB perf.data (60084 samples) ] ~ # perf report # To display the perf.data header info, please use --header/--header-only options. # To display the perf.data header info, please use --header/--header-only options. # # # Total Lost Samples: 0 # # Samples: 60K of event 'cycles' # Event count (approx.): 35706225414 # # Overhead Command Shared Object Symbol # ........ ....... ................. ...... # 21.07% a.out [kernel.kallsyms] [k] _raw_spin_unlock_irq 8.23% a.out [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 6.67% a.out [kernel.kallsyms] [k] filemap_map_pages 6.16% a.out [kernel.kallsyms] [k] __zram_bvec_write 5.36% a.out [kernel.kallsyms] [k] ptep_clear_flush 3.71% a.out [kernel.kallsyms] [k] _raw_spin_lock 3.49% a.out [kernel.kallsyms] [k] memset64 1.63% a.out [kernel.kallsyms] [k] clear_page 1.42% a.out [kernel.kallsyms] [k] _raw_spin_unlock 1.26% a.out [kernel.kallsyms] [k] mod_zone_state.llvm.8525150236079521930 1.23% a.out [kernel.kallsyms] [k] xas_load 1.15% a.out [kernel.kallsyms] [k] zram_slot_lock ptep_clear_flush() takes 5.36% CPU in the micro-benchmark swapping in/out a page mapped by only one process. If the page is mapped by multiple processes, typically, like more than 100 on a phone, the overhead would be much higher as we have to run tlb flush 100 times for one single page. Plus, tlb flush overhead will increase with the number of CPU cores due to the bad scalability of tlb shootdown in HW, so those ARM64 servers should expect much higher overhead. Further perf annonate shows 95% cpu time of ptep_clear_flush is actually used by the final dsb() to wait for the completion of tlb flush. This provides us a very good chance to leverage the existing batched tlb in kernel. The minimum modification is that we only send async tlbi in the first stage and we send dsb while we have to sync in the second stage. With the above simplest micro benchmark, collapsed time to finish the program decreases around 5%. Typical collapsed time w/o patch: ~ # time taskset -c 4 ./a.out 0.21user 14.34system 0:14.69elapsed w/ patch: ~ # time taskset -c 4 ./a.out 0.22user 13.45system 0:13.80elapsed Also tested with benchmark in the commit on Kunpeng920 arm64 server and observed an improvement around 12.5% with command `time ./swap_bench`. w/o w/ real 0m13.460s 0m11.771s user 0m0.248s 0m0.279s sys 0m12.039s 0m11.458s Originally it's noticed a 16.99% overhead of ptep_clear_flush() which has been eliminated by this patch: [root@localhost yang]# perf record -- ./swap_bench && perf report [...] 16.99% swap_bench [kernel.kallsyms] [k] ptep_clear_flush It is tested on 4,8,128 CPU platforms and shows to be beneficial on large systems but may not have improvement on small systems like on a 4 CPU platform. Also this patch improve the performance of page migration. Using pmbench and tries to migrate the pages of pmbench between node 0 and node 1 for 100 times for 1G memory, this patch decrease the time used around 20% (prev 18.338318910 sec after 13.981866350 sec) and saved the time used by ptep_clear_flush(). Link: https://lkml.kernel.org/r/20230717131004.12662-5-yangyicong@huawei.comTested-by:Yicong Yang <yangyicong@hisilicon.com> Tested-by:
Xin Hao <xhao@linux.alibaba.com> Tested-by:
Punit Agrawal <punit.agrawal@bytedance.com> Signed-off-by:
Barry Song <v-songbaohua@oppo.com> Signed-off-by:
Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by:
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