- 29 Dec, 2023 40 commits
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David Hildenbrand authored
Let's convert try_to_unmap_one() and try_to_migrate_one(). Link: https://lkml.kernel.org/r/20231220224504.646757-31-david@redhat.comSigned-off-by:
David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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David Hildenbrand authored
Let's convert migrate_vma_collect_pmd(). While at it, perform more folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-30-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert zap_pte_range() and closely-related tlb_flush_rmap_batch(). While at it, perform some more folio conversion in zap_pte_range(). Link: https://lkml.kernel.org/r/20231220224504.646757-29-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert replace_page(). Link: https://lkml.kernel.org/r/20231220224504.646757-28-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert __collapse_huge_page_copy_succeeded() and collapse_pte_mapped_thp(). While at it, perform some more folio conversion in __collapse_huge_page_copy_succeeded(). We can get rid of release_pte_page(). Link: https://lkml.kernel.org/r/20231220224504.646757-27-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert zap_huge_pmd() and set_pmd_migration_entry(). While at it, perform some more folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-26-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert __replace_page(). Link: https://lkml.kernel.org/r/20231220224504.646757-25-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's mimic what we did with folio_add_file_rmap_*() and folio_add_anon_rmap_*() so we can similarly replace page_remove_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. We're adding folio_remove_rmap_ptes() handling right away, as we want to use that soon for batching rmap operations when unmapping PTE-mapped large folios. Link: https://lkml.kernel.org/r/20231220224504.646757-24-david@redhat.comSigned-off-by:
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David Hildenbrand authored
No longer used, let's remove it and clarify RMAP_NONE/RMAP_EXCLUSIVE a bit. Link: https://lkml.kernel.org/r/20231220224504.646757-23-david@redhat.comSigned-off-by:
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David Hildenbrand authored
All users are gone, remove it and all traces. Link: https://lkml.kernel.org/r/20231220224504.646757-22-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert restore_exclusive_pte() and do_swap_page(). While at it, perform some folio conversion in restore_exclusive_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-21-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert unuse_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-20-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert replace_page(). While at it, perform some folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-19-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert remove_migration_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-18-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert remove_migration_pmd(). No need to set RMAP_COMPOUND, that we will remove soon. Link: https://lkml.kernel.org/r/20231220224504.646757-17-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's use folio_add_anon_rmap_ptes(), batching the rmap operations. While at it, use more folio operations (but only in the code branch we're touching), use VM_WARN_ON_FOLIO(), and pass RMAP_EXCLUSIVE instead of manually setting PageAnonExclusive. We should never see non-anon pages on that branch: otherwise, the existing page_add_anon_rmap() call would have been flawed already. Link: https://lkml.kernel.org/r/20231220224504.646757-16-david@redhat.comSigned-off-by:
Yin Fengwei <fengwei.yin@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by:
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David Hildenbrand authored
Let's mimic what we did with folio_add_file_rmap_*() so we can similarly replace page_add_anon_rmap() next. Make the compiler always special-case on the granularity by using __always_inline. For the PageAnonExclusive sanity checks, when adding a PMD mapping, we're now also checking each individual subpage covered by that PMD, instead of only the head page. Note that the new functions ignore the RMAP_COMPOUND flag, which we will remove as soon as page_add_anon_rmap() is gone. Link: https://lkml.kernel.org/r/20231220224504.646757-15-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's factor it out to prepare for reuse as we convert page_add_anon_rmap() to folio_add_anon_rmap_[pte|ptes|pmd](). Make the compiler always special-case on the granularity by using __always_inline. Link: https://lkml.kernel.org/r/20231220224504.646757-14-david@redhat.comSigned-off-by:
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David Hildenbrand authored
All users are gone, let's remove it. Link: https://lkml.kernel.org/r/20231220224504.646757-13-david@redhat.comSigned-off-by:
Ryan Roberts <ryan.roberts@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by:
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David Hildenbrand authored
Let's convert mfill_atomic_install_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-12-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert remove_migration_pte(). Link: https://lkml.kernel.org/r/20231220224504.646757-11-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert remove_migration_pmd() and while at it, perform some folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-10-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's convert insert_page_into_pte_locked() and do_set_pmd(). While at it, perform some folio conversion. Link: https://lkml.kernel.org/r/20231220224504.646757-9-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's get rid of the compound parameter and instead define explicitly which mappings we're adding. That is more future proof, easier to read and harder to mess up. Use an enum to express the granularity internally. Make the compiler always special-case on the granularity by using __always_inline. Replace the "compound" check by a switch-case that will be removed by the compiler completely. Add plenty of sanity checks with CONFIG_DEBUG_VM. Replace the folio_test_pmd_mappable() check by a config check in the caller and sanity checks. Convert the single user of folio_add_file_rmap_range(). While at it, consistently use "int" instead of "unisgned int" in rmap code when dealing with mapcounts and the number of pages. This function design can later easily be extended to PUDs and to batch PMDs. Note that for now we don't support anything bigger than PMD-sized folios (as we cleanly separated hugetlb handling). Sanity checks will catch if that ever changes. Next up is removing page_remove_rmap() along with its "compound" parameter and smilarly converting all other rmap functions. Link: https://lkml.kernel.org/r/20231220224504.646757-8-david@redhat.comSigned-off-by:
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David Hildenbrand authored
Let's make sure we end up with the right folios in the right functions when adding an anon rmap, just like we already do in the other rmap functions. Link: https://lkml.kernel.org/r/20231220224504.646757-7-david@redhat.comSigned-off-by:
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David Hildenbrand authored
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. So let's introduce and use hugetlb_try_dup_anon_rmap() to make all hugetlb handling use dedicated hugetlb_* rmap functions. Add sanity checks that we end up with the right folios in the right functions. Note that try_to_unmap_one() does not need care. Easy to spot because among all that nasty hugetlb special-casing in that function, we're not using set_huge_pte_at() on the anon path -- well, and that code assumes that we would want to swapout. Link: https://lkml.kernel.org/r/20231220224504.646757-6-david@redhat.comSigned-off-by:
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David Hildenbrand authored
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. So let's introduce and use hugetlb_try_dup_anon_rmap() to make all hugetlb handling use dedicated hugetlb_* rmap functions. Add sanity checks that we end up with the right folios in the right functions. Note that is_device_private_page() does not apply to hugetlb. Link: https://lkml.kernel.org/r/20231220224504.646757-5-david@redhat.comSigned-off-by:
Muchun Song <songmuchun@bytedance.com> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Signed-off-by:
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David Hildenbrand authored
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Right now we're using page_dup_file_rmap() in some cases where "ordinary" rmap code would have used page_add_file_rmap(). So let's introduce and use hugetlb_add_file_rmap() instead. We won't be adding a "hugetlb_dup_file_rmap()" functon for the fork() case, as it would be doing the same: "dup" is just an optimization for "add". What remains is a single page_dup_file_rmap() call in fork() code. Add sanity checks that we end up with the right folios in the right functions. Link: https://lkml.kernel.org/r/20231220224504.646757-4-david@redhat.comSigned-off-by:
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David Hildenbrand authored
hugetlb rmap handling differs quite a lot from "ordinary" rmap code. For example, hugetlb currently only supports entire mappings, and treats any mapping as mapped using a single "logical PTE". Let's move it out of the way so we can overhaul our "ordinary" rmap. implementation/interface. Let's introduce and use hugetlb_remove_rmap() and remove the hugetlb code from page_remove_rmap(). This effectively removes one check on the small-folio path as well. Add sanity checks that we end up with the right folios in the right functions. Note: all possible candidates that need care are page_remove_rmap() that pass compound=true. Link: https://lkml.kernel.org/r/20231220224504.646757-3-david@redhat.comSigned-off-by:Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by:
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David Hildenbrand authored
Patch series "mm/rmap: interface overhaul", v2. This series overhauls the rmap interface, to get rid of the "bool compound" / RMAP_COMPOUND parameter with the goal of making the interface less error prone, more future proof, and more natural to extend to "batching". Also, this converts the interface to always consume folio+subpage, which speeds up operations on large folios. Further, this series adds PTE-batching variants for 4 rmap functions, whereby only folio_add_anon_rmap_ptes() is used for batching in this series when PTE-remapping a PMD-mapped THP. folio_remove_rmap_ptes(), folio_try_dup_anon_rmap_ptes() and folio_dup_file_rmap_ptes() will soon come in handy[1,2]. This series performs a lot of folio conversion along the way. Most of the added LOC in the diff are only due to documentation. As we're moving to a pte/pmd interface where we clearly express the mapping granularity we are dealing with, we first get the remainder of hugetlb out of the way, as it is special and expected to remain special: it treats everything as a "single logical PTE" and only currently allows entire mappings. Even if we'd ever support partial mappings, I strongly assume the interface and implementation will still differ heavily: hopefull we can avoid working on subpages/subpage mapcounts completely and only add a "count" parameter for them to enable batching. New (extended) hugetlb interface that operates on entire folio: * hugetlb_add_new_anon_rmap() -> Already existed * hugetlb_add_anon_rmap() -> Already existed * hugetlb_try_dup_anon_rmap() * hugetlb_try_share_anon_rmap() * hugetlb_add_file_rmap() * hugetlb_remove_rmap() New "ordinary" interface for small folios / THP:: * folio_add_new_anon_rmap() -> Already existed * folio_add_anon_rmap_[pte|ptes|pmd]() * folio_try_dup_anon_rmap_[pte|ptes|pmd]() * folio_try_share_anon_rmap_[pte|pmd]() * folio_add_file_rmap_[pte|ptes|pmd]() * folio_dup_file_rmap_[pte|ptes|pmd]() * folio_remove_rmap_[pte|ptes|pmd]() folio_add_new_anon_rmap() will always map at the largest granularity possible (currently, a single PMD to cover a PMD-sized THP). Could be extended if ever required. In the future, we might want "_pud" variants and eventually "_pmds" variants for batching. I ran some simple microbenchmarks on an Intel(R) Xeon(R) Silver 4210R: measuring munmap(), fork(), cow, MADV_DONTNEED on each PTE ... and PTE remapping PMD-mapped THPs on 1 GiB of memory. For small folios, there is barely a change (< 1% improvement for me). For PTE-mapped THP: * PTE-remapping a PMD-mapped THP is more than 10% faster. * fork() is more than 4% faster. * MADV_DONTNEED is 2% faster * COW when writing only a single byte on a COW-shared PTE is 1% faster * munmap() barely changes (< 1%). [1] https://lkml.kernel.org/r/20230810103332.3062143-1-ryan.roberts@arm.com [2] https://lkml.kernel.org/r/20231204105440.61448-1-ryan.roberts@arm.com This patch (of 40): Let's just call it "hugetlb_". Yes, it's all already inconsistent and confusing because we have a lot of "hugepage_" functions for legacy reasons. But "hugetlb" cannot possibly be confused with transparent huge pages, and it matches "hugetlb.c" and "folio_test_hugetlb()". So let's minimize confusion in rmap code. Link: https://lkml.kernel.org/r/20231220224504.646757-1-david@redhat.com Link: https://lkml.kernel.org/r/20231220224504.646757-2-david@redhat.comSigned-off-by:
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Andrey Konovalov authored
memcpy the alloc/free tracks when collecting the information about a bad access instead of copying fields one by one. Link: https://lkml.kernel.org/r/20231221183540.168428-4-andrey.konovalov@linux.dev Fixes: 5d4c6ac9 ("kasan: record and report more information") Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Reviewed-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Juntong Deng <juntong.deng@outlook.com> Signed-off-by:
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Andrey Konovalov authored
Avoid duplicating code for saving extra info into tracks: reuse the common function for this. Link: https://lkml.kernel.org/r/20231221183540.168428-3-andrey.konovalov@linux.dev Fixes: 5d4c6ac9 ("kasan: record and report more information") Signed-off-by:
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Andrey Konovalov authored
Avoid duplicating fields of kasan_track in kasan_stack_ring_entry: reuse the structure. Link: https://lkml.kernel.org/r/20231221183540.168428-2-andrey.konovalov@linux.dev Fixes: 5d4c6ac9 ("kasan: record and report more information") Signed-off-by:
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Andrey Konovalov authored
Reorganize the code to avoid nested if/else checks to improve the readability. Also drop the confusing comments about KMALLOC_MAX_SIZE checks: they are relevant for both SLUB and SLAB (originally, the comments likely confused KMALLOC_MAX_SIZE with KMALLOC_MAX_CACHE_SIZE). Link: https://lkml.kernel.org/r/20231221183540.168428-1-andrey.konovalov@linux.dev Fixes: a5989d4e ("kasan: improve free meta storage in Generic KASAN") Signed-off-by:
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Andrey Konovalov authored
Checking all 256 possible tag values in the match_all_mem_tag KASAN test is slow and produces 256 reports. Instead, just check the first 8 and the last 8. Link: https://lkml.kernel.org/r/6fe51262defd80cdc1150c42404977aafd1b6167.1703188911.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
A number of KASAN tests rely on the fact that calling kmalloc with a size larger than an order-1 page falls back onto page_alloc. This fallback was originally only implemented for SLUB, but since commit d6a71648 ("mm/slab: kmalloc: pass requests larger than order-1 page to page allocator"), it is also implemented for SLAB. Thus, drop the SLUB checks from the tests. Link: https://lkml.kernel.org/r/c82099b6fb365b6f4c2c21b112d4abb4dfd83e53.1703188911.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
KASAN uses EXPORT_SYMBOL_GPL for symbols whose exporting is only required for KASAN tests when they are built as a module. kasan_poison is one on those symbols, so export it as GPL. Link: https://lkml.kernel.org/r/171d0b8b2e807d04cca74f973830f9b169e06fb8.1703188911.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Check that vmalloc poisoning is not disabled via command line when running the vmalloc-related KASAN tests. Skip the tests otherwise. Link: https://lkml.kernel.org/r/954456e50ac98519910c3e24a479a18eae62f8dd.1703188911.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
Never enable the kasan_flag_vmalloc static branch unless CONFIG_KASAN_VMALLOC is enabled. This does not fix any observable bugs (vmalloc annotations for the HW_TAGS mode are no-op with CONFIG_KASAN_VMALLOC disabled) but rather just cleans up the code. Link: https://lkml.kernel.org/r/3e5c933c8f6b59bd587efb05c407964be951772c.1703188911.git.andreyknvl@google.comSigned-off-by:
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Andrey Konovalov authored
1. Do not untag addresses that are passed to is_kfence_address: it tolerates tagged addresses. 2. Move is_kfence_address checks from internal KASAN functions (kasan_poison/unpoison, etc.) to external-facing ones. Note that kasan_poison/unpoison are never called outside of KASAN/slab code anymore; the comment is wrong, so drop it. 3. Simplify/reorganize the code around the updated checks. Link: https://lkml.kernel.org/r/1065732315ef4e141b6177d8f612232d4d5bc0ab.1703188911.git.andreyknvl@google.comSigned-off-by:
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