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2024-02-22highmem: add kernel-doc for memcpy_*_folio()Matthew Wilcox (Oracle)
This was inadvertently skipped when adding the new functions. Link: https://lkml.kernel.org/r/20240124181217.1761674-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10mm: add folio_fill_tail() and use it in iomapMatthew Wilcox (Oracle)
The iomap code was limited to PAGE_SIZE bytes; generalise it to cover an arbitrary-sized folio, and move it to be a common helper. [akpm@linux-foundation.org: fix folio_fill_tail(), per Andreas Gruenbacher] Link: https://lkml.kernel.org/r/20231107212643.3490372-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-10mm: add folio_zero_tail() and use it in ext4Matthew Wilcox (Oracle)
Patch series "Add folio_zero_tail() and folio_fill_tail()". I'm trying to make it easier for filesystems with tailpacking / stuffing / inline data to use folios. The primary function here is folio_fill_tail(). You give it a pointer to memory where the data currently is, and it takes care of copying it into the folio at that offset. That works for gfs2 & iomap. Then There's Ext4. Rather than gin up some kind of specialist "Here's a two pointers to two blocks of memory" routine, just let it do its current thing, and let it call folio_zero_tail(), which is also called by folio_fill_tail(). Other filesystems can be converted later; these ones seemed like good examples as they're already partly or completely converted to folios. This patch (of 3): Instead of unmapping the folio after copying the data to it, then mapping it again to zero the tail, provide folio_zero_tail() to zero the tail of an already-mapped folio. [akpm@linux-foundation.org: fix kerneldoc argument ordering] Link: https://lkml.kernel.org/r/20231107212643.3490372-1-willy@infradead.org Link: https://lkml.kernel.org/r/20231107212643.3490372-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-12-06highmem: fix a memory copy problem in memcpy_from_folioSu Hui
Clang static checker complains that value stored to 'from' is never read. And memcpy_from_folio() only copy the last chunk memory from folio to destination. Use 'to += chunk' to replace 'from += chunk' to fix this typo problem. Link: https://lkml.kernel.org/r/20231130034017.1210429-1-suhui@nfschina.com Fixes: b23d03ef7af5 ("highmem: add memcpy_to_folio() and memcpy_from_folio()") Signed-off-by: Su Hui <suhui@nfschina.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Tom Rix <trix@redhat.com> Cc: Tony Luck <tony.luck@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-25highmem: Add folio_release_kmap()Matthew Wilcox (Oracle)
This is the folio equivalent of unmap_and_put_page(), which remains as a wrapper for it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20230921200746.3303942-1-willy@infradead.org>
2023-08-18highmem: add memcpy_to_folio() and memcpy_from_folio()Matthew Wilcox (Oracle)
Patch series "More filesystem folio conversions for 6.6". Remove the only spots in affs which actually use a struct page; there are a few places where one is mentioned, but it's part of the interface. The rest of this is removing the remaining calls to set_bh_page(), and then removing the function before any new users show up. This patch (of 7): These are the folio equivalent of memcpy_to_page() and memcpy_from_page(). [agruenba@redhat.com: use correct chunk size in memcpy()] Link: https://lkml.kernel.org/r/20230802144354.1023099-1-agruenba@redhat.com Link: https://lkml.kernel.org/r/20230713035512.4139457-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230713035512.4139457-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: David Sterba <dsterba@suse.com> Cc: Jan Kara <jack@suse.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Pankaj Raghav <p.raghav@samsung.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Tom Rix <trix@redhat.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-05highmem: Rename put_and_unmap_page() to unmap_and_put_page()Fabio M. De Francesco
With commit 849ad04cf562a ("new helper: put_and_unmap_page()"), Al Viro introduced the put_and_unmap_page() to use in those many places where we have a common pattern consisting of calls to kunmap_local() + put_page(). Obviously, first we unmap and then we put pages. Instead, the original name of this helper seems to imply that we first put and then unmap. Therefore, rename the helper and change the only known upstreamed user (i.e., fs/sysv) before this helper enters common use and might become difficult to find all call sites and instead easy to break the builds. Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Message-Id: <20230602103307.5637-1-fmdefrancesco@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-04-18mm/hwpoison: introduce copy_mc_highpageJiaqi Yan
Similar to how copy_mc_user_highpage is implemented for copy_user_highpage on #MC supported architecture, introduce the #MC handled version of copy_highpage. This helper has immediate usage when khugepaged wants to copy file-backed memory pages and tolerate #MC. Link: https://lkml.kernel.org/r/20230329151121.949896-3-jiaqiyan@google.com Signed-off-by: Jiaqi Yan <jiaqiyan@google.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: David Stevens <stevensd@chromium.org> Cc: Hugh Dickins <hughd@google.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Tong Tiangen <tongtiangen@huawei.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-28kasan: call clear_page with a match-all tag instead of changing page tagPeter Collingbourne
Instead of changing the page's tag solely in order to obtain a pointer with a match-all tag and then changing it back again, just convert the pointer that we get from kmap_atomic() into one with a match-all tag before passing it to clear_page(). On a certain microarchitecture, this has been observed to cause a measurable improvement in microbenchmark performance, presumably as a result of being able to avoid the atomic operations on the page tag. Link: https://lkml.kernel.org/r/20230216195924.3287772-1-pcc@google.com Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/I0249822cc29097ca7a04ad48e8eb14871f80e711 Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-07new helper: put_and_unmap_page()Al Viro
kunmap_local() + put_page(), as done by e.g. ext2 directory handling. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-02-09mm: fix memcpy_from_file_folio() integer underflowMatthew Wilcox (Oracle)
If we have a HIGHMEM system with a large folio, 'offset' may be larger than PAGE_SIZE, and so min_t will cap at 'len' instead of the intended end-of-page. That can overflow into the next page which is likely to be unmapped and fault, but could theoretically copy the wrong data. Link: https://lkml.kernel.org/r/Y919vmSrtAgsf6K3@casper.infradead.org Fixes: 00cdf76012ab ("mm: add memcpy_from_file_folio()") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: add memcpy_from_file_folio()Matthew Wilcox (Oracle)
This is the equivalent of memcpy_from_page(). It differs in that it takes the position in a file instead of offset in a folio, it accepts the total number of bytes to be copied (instead of the number of bytes to be copied from this folio) and it returns how many bytes were copied from the folio, rather than making the caller calculate that and then checking if the caller got it right. [akpm@linux-foundation.org: fix typo in comment] Link: https://lkml.kernel.org/r/20230126201552.1681588-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-02mm: add vma_alloc_zeroed_movable_folio()Matthew Wilcox (Oracle)
Replace alloc_zeroed_user_highpage_movable(). The main difference is returning a folio containing a single page instead of returning the page, but take the opportunity to rename the function to match other allocation functions a little better and rewrite the documentation to place more emphasis on the zeroing rather than the highmem aspect. Link: https://lkml.kernel.org/r/20230116191813.2145215-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18mm: fix spelling mistake in highmem.hFabio M. De Francesco
Substitute "higmem" with "highmem" in highmem.h. Link: https://lkml.kernel.org/r/20230105121305.30714-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: "Matthew Wilcox (Oracle)" <willy@infradead.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-18mm: remove an ambiguous sentence from kmap_local_folio() kdocsFabio M. De Francesco
In the kdocs of kmap_local_folio() there is a an ambiguous sentence which suggests to use this API "only when really necessary". On the contrary, since kmap() and kmap_atomic() are deprecated, both kmap_local_folio(), as well as kmap_local_page(), must be preferred to the previous ones. Therefore, remove the above-mentioned sentence exactly how it has previously been done for the kmap_local_page() kdocs in commit 72f1c55adf70 ("highmem: delete a sentence from kmap_local_page() kdocs"). Link: https://lkml.kernel.org/r/20230105120424.30055-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30mm, hwpoison: try to recover from copy-on write faultsTony Luck
Patch series "Copy-on-write poison recovery", v3. Part 1 deals with the process that triggered the copy on write fault with a store to a shared read-only page. That process is send a SIGBUS with the usual machine check decoration to specify the virtual address of the lost page, together with the scope. Part 2 sets up to asynchronously take the page with the uncorrected error offline to prevent additional machine check faults. H/t to Miaohe Lin <linmiaohe@huawei.com> and Shuai Xue <xueshuai@linux.alibaba.com> for pointing me to the existing function to queue a call to memory_failure(). On x86 there is some duplicate reporting (because the error is also signalled by the memory controller as well as by the core that triggered the machine check). Console logs look like this: This patch (of 2): If the kernel is copying a page as the result of a copy-on-write fault and runs into an uncorrectable error, Linux will crash because it does not have recovery code for this case where poison is consumed by the kernel. It is easy to set up a test case. Just inject an error into a private page, fork(2), and have the child process write to the page. I wrapped that neatly into a test at: git://git.kernel.org/pub/scm/linux/kernel/git/aegl/ras-tools.git just enable ACPI error injection and run: # ./einj_mem-uc -f copy-on-write Add a new copy_user_highpage_mc() function that uses copy_mc_to_kernel() on architectures where that is available (currently x86 and powerpc). When an error is detected during the page copy, return VM_FAULT_HWPOISON to caller of wp_page_copy(). This propagates up the call stack. Both x86 and powerpc have code in their fault handler to deal with this code by sending a SIGBUS to the application. Note that this patch avoids a system crash and signals the process that triggered the copy-on-write action. It does not take any action for the memory error that is still in the shared page. To handle that a call to memory_failure() is needed. But this cannot be done from wp_page_copy() because it holds mmap_lock(). Perhaps the architecture fault handlers can deal with this loose end in a subsequent patch? On Intel/x86 this loose end will often be handled automatically because the memory controller provides an additional notification of the h/w poison in memory, the handler for this will call memory_failure(). This isn't a 100% solution. If there are multiple errors, not all may be logged in this way. [tony.luck@intel.com: add call to kmsan_unpoison_memory(), per Miaohe Lin] Link: https://lkml.kernel.org/r/20221031201029.102123-2-tony.luck@intel.com Link: https://lkml.kernel.org/r/20221021200120.175753-1-tony.luck@intel.com Link: https://lkml.kernel.org/r/20221021200120.175753-2-tony.luck@intel.com Signed-off-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Shuai Xue <xueshuai@linux.alibaba.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03mm: kmsan: maintain KMSAN metadata for page operationsAlexander Potapenko
Insert KMSAN hooks that make the necessary bookkeeping changes: - poison page shadow and origins in alloc_pages()/free_page(); - clear page shadow and origins in clear_page(), copy_user_highpage(); - copy page metadata in copy_highpage(), wp_page_copy(); - handle vmap()/vunmap()/iounmap(); Link: https://lkml.kernel.org/r/20220915150417.722975-15-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08highmem: delete a sentence from kmap_local_page() kdocsFabio M. De Francesco
kmap_local_page() should always be preferred in place of kmap() and kmap_atomic(). "Only use when really necessary." is not consistent with the Documentation/mm/highmem.rst and these kdocs it embeds. Therefore, delete the above-mentioned sentence from kdocs. Link: https://lkml.kernel.org/r/20220728154844.10874-7-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08highmem: specify that kmap_local_page() is callable from interruptsFabio M. De Francesco
In a recent thread about converting kmap() to kmap_local_page(), the safety of calling kmap_local_page() was questioned.[1] "any context" should probably be enough detail for users who want to know whether or not kmap_local_page() can be called from interrupts. However, Linux still has kmap_atomic() which might make users think they must use the latter in interrupts. Add "including interrupts" for better clarity. [1] https://lore.kernel.org/lkml/3187836.aeNJFYEL58@opensuse/ Link: https://lkml.kernel.org/r/20220728154844.10874-3-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-08highmem: remove unneeded spaces in kmap_local_page() kdocsFabio M. De Francesco
Patch series "highmem: Extend kmap_local_page() documentation", v2. The Highmem interface is evolving and the current documentation does not reflect the intended uses of each of the calls. Furthermore, after a recent series of reworks, the differences of the calls can still be confusing and may lead to the expanded use of calls which are deprecated. This series is the second round of changes towards an enhanced documentation of the Highmem's interface; at this stage the patches are only focused to kmap_local_page(). In addition it also contains some minor clean ups. This patch (of 7): In the kdocs of kmap_local_page(), the description of @page starts after several unnecessary spaces. Therefore, remove those spaces. Link: https://lkml.kernel.org/r/20220728154844.10874-1-fmdefrancesco@gmail.com Link: https://lkml.kernel.org/r/20220728154844.10874-2-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-05Merge tag 'mm-stable-2022-08-03' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ...
2022-07-03mm: introduce clear_highpage_kasan_taggedAndrey Konovalov
Add a clear_highpage_kasan_tagged() helper that does clear_highpage() on a page potentially tagged by KASAN. This helper is used by the following patch. Link: https://lkml.kernel.org/r/4471979b46b2c487787ddcd08b9dc5fedd1b6ffd.1654798516.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-03Documentation: highmem: use literal block for code example in highmem.h commentBagas Sanjaya
When building htmldocs on Linus's tree, there are inline emphasis warnings on include/linux/highmem.h: Documentation/vm/highmem:166: ./include/linux/highmem.h:154: WARNING: Inline emphasis start-string without end-string. Documentation/vm/highmem:166: ./include/linux/highmem.h:157: WARNING: Inline emphasis start-string without end-string. These warnings above are due to comments in code example at the mentioned lines above are enclosed by double dash (--), which confuses Sphinx as inline markup delimiters instead. Fix these warnings by indenting the code example with literal block indentation and making the comments C comments. Link: https://lkml.kernel.org/r/20220622084546.17745-1-bagasdotme@gmail.com Fixes: 85a85e7601263f ("Documentation/vm: move "Using kmap-atomic" to highmem.h") Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Tested-by: Ira Weiny <ira.weiny@intel.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: "Fabio M. De Francesco" <fmdefrancesco@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-06-16mm/highmem: delete memmove_page()Fabio M. De Francesco
Matthew Wilcox reported that, while he was looking at memmove_page(), he realized that it can't actually work. The reasons are hidden in its implementation, which makes use of memmove() on logical addresses provided by kmap_local_page(). memmove() does the wrong thing when it tests "if (dest <= src)". Therefore, delete memmove_page(). No need to change any other code because we have no call sites of memmove_page() across the whole kernel. Link: https://lkml.kernel.org/r/20220606141533.555-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reported-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13Documentation/vm: move "Using kmap-atomic" to highmem.hFabio M. De Francesco
The use of kmap_atomic() is new code is being deprecated in favor of kmap_local_page(). For this reason the "Using kmap_atomic" section in highmem.rst is obsolete and unnecessary, but it can still help developers if it were moved to kdocs in highmem.h. Therefore, move the relevant parts of this section from highmem.rst and merge them with the kdocs in highmem.h. Link: https://lkml.kernel.org/r/20220428212455.892-4-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Ira Weiny <ira.weiny@intel.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/highmem: fix kernel-doc warnings in highmem*.hFabio M. De Francesco
Patch series "Extend and reorganize Highmem's documentation", v4. This series has the purpose to extend and reorganize Highmem's documentation. This is a work in progress because some information should still be moved from highmem.rst to highmem.h and highmem-internal.h. Specifically I'm talking about moving the "how to" information to the relevant headers, as it as been suggested by Ira Weiny (Intel). Also, this is a work in progress because some kdocs in highmem.h and highmem-internal.h should be improved. This patch (of 4): `scripts/kernel-doc -v -none include/linux/highmem*` reports the following warnings: include/linux/highmem.h:160: warning: expecting prototype for kunmap_atomic(). Prototype was for nr_free_highpages() instead include/linux/highmem.h:204: warning: No description found for return value of 'alloc_zeroed_user_highpage_movable' include/linux/highmem-internal.h:256: warning: Function parameter or member '__addr' not described in 'kunmap_atomic' include/linux/highmem-internal.h:256: warning: Excess function parameter 'addr' description in 'kunmap_atomic' Fix these warnings by (1) moving the kernel-doc comments from highmem.h to highmem-internal.h (which is the file were the kunmap_atomic() macro is actually defined), (2) extending and merging it with the comment which was already in highmem-internal.h, and (3) using correct parameter names (4) correcting a few technical inaccuracies in comments, and (5) adding a deprecation notice in kunmap_atomic() for consistency with kmap_atomic(). Link: https://lkml.kernel.org/r/20220428212455.892-1-fmdefrancesco@gmail.com Link: https://lkml.kernel.org/r/20220428212455.892-2-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Peter Collingbourne <pcc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-13mm/highmem: VM_BUG_ON() if offset + len > PAGE_SIZEFabio M. De Francesco
Add VM_BUG_ON() bounds checking to make sure that, if "offset + len> PAGE_SIZE", memset() does not corrupt data in adjacent pages. Mainly to match all the similar functions in highmem.h. Link: https://lkml.kernel.org/r/20220426193020.8710-1-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2021-11-18mm: Add functions to zero portions of a folioMatthew Wilcox (Oracle)
These functions are wrappers around zero_user_segments(), which means that zero_user_segments() can now be called for compound pages even when CONFIG_TRANSPARENT_HUGEPAGE is disabled. Use 'xend' as the name of the parameter to indicate that this is an excluded end, not the more usual included end. Excluding the end makes more sense to the callers, but can cause confusion to readers who are more used to seeing included ends. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2021-11-17Add linux/cacheflush.hMatthew Wilcox (Oracle)
Many architectures do not include asm-generic/cacheflush.h, so turn the includes on their head and add linux/cacheflush.h which includes asm/cacheflush.h. Move the flush_dcache_folio() declaration from asm-generic/cacheflush.h to linux/cacheflush.h and change linux/highmem.h to include linux/cacheflush.h instead of asm/cacheflush.h so that all necessary places will see flush_dcache_folio(). More functions should have their default implementations moved in the future, but those are for follow-on patches. This fixes csky, sparc and sparc64 which were missed in the commit which added flush_dcache_folio(). Fixes: 08b0b0059bf1 ("mm: Add flush_dcache_folio()") Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2021-11-06Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: "257 patches. Subsystems affected by this patch series: scripts, ocfs2, vfs, and mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache, gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools, memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm, vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram, cleanups, kfence, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits) mm/damon: remove return value from before_terminate callback mm/damon: fix a few spelling mistakes in comments and a pr_debug message mm/damon: simplify stop mechanism Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions Docs/admin-guide/mm/damon/start: simplify the content Docs/admin-guide/mm/damon/start: fix a wrong link Docs/admin-guide/mm/damon/start: fix wrong example commands mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on mm/damon: remove unnecessary variable initialization Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM) selftests/damon: support watermarks mm/damon/dbgfs: support watermarks mm/damon/schemes: activate schemes based on a watermarks mechanism tools/selftests/damon: update for regions prioritization of schemes mm/damon/dbgfs: support prioritization weights mm/damon/vaddr,paddr: support pageout prioritization mm/damon/schemes: prioritize regions within the quotas mm/damon/selftests: support schemes quotas mm/damon/dbgfs: support quotas of schemes ...
2021-11-06mm/highmem: remove deprecated kmap_atomicIra Weiny
kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace the uses of kmap_atomic() within the highmem code. On profiling clear_huge_page() using ftrace an improvement of 62% was observed on the below setup. Setup:- Below data has been collected on Qualcomm's SM7250 SoC THP enabled (kernel v4.19.113) with only CPU-0(Cortex-A55) and CPU-7(Cortex-A76) switched on and set to max frequency, also DDR set to perf governor. FTRACE Data:- Base data:- Number of iterations: 48 Mean of allocation time: 349.5 us std deviation: 74.5 us v4 data:- Number of iterations: 48 Mean of allocation time: 131 us std deviation: 32.7 us The following simple userspace experiment to allocate 100MB(BUF_SZ) of pages and writing to it gave us a good insight, we observed an improvement of 42% in allocation and writing timings. ------------------------------------------------------------- Test code snippet ------------------------------------------------------------- clock_start(); buf = malloc(BUF_SZ); /* Allocate 100 MB of memory */ for(i=0; i < BUF_SZ_PAGES; i++) { *((int *)(buf + (i*PAGE_SIZE))) = 1; } clock_end(); ------------------------------------------------------------- Malloc test timings for 100MB anon allocation:- Base data:- Number of iterations: 100 Mean of allocation time: 31831 us std deviation: 4286 us v4 data:- Number of iterations: 100 Mean of allocation time: 18193 us std deviation: 4915 us [willy@infradead.org: fix zero_user_segments()] Link: https://lkml.kernel.org/r/YYVhHCJcm2DM2G9u@casper.infradead.org Link: https://lkml.kernel.org/r/20210204073255.20769-2-prathu.baronia@oneplus.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Prathu Baronia <prathu.baronia@oneplus.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-10-18mm: Add kmap_local_folio()Matthew Wilcox (Oracle)
This allows us to map a portion of a folio. Callers can only expect to access up to the next page boundary. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Vlastimil Babka <vbabka@suse.cz>
2021-09-03mm: remove flush_kernel_dcache_pageChristoph Hellwig
flush_kernel_dcache_page is a rather confusing interface that implements a subset of flush_dcache_page by not being able to properly handle page cache mapped pages. The only callers left are in the exec code as all other previous callers were incorrect as they could have dealt with page cache pages. Replace the calls to flush_kernel_dcache_page with calls to flush_dcache_page, which for all architectures does either exactly the same thing, can contains one or more of the following: 1) an optimization to defer the cache flush for page cache pages not mapped into userspace 2) additional flushing for mapped page cache pages if cache aliases are possible Link: https://lkml.kernel.org/r/20210712060928.4161649-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Alex Shi <alexs@kernel.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Cercueil <paul@crapouillou.net> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23mm: use kmap_local_page in memzero_pageChristoph Hellwig
The commit message introducing the global memzero_page explicitly mentions switching to kmap_local_page in the commit log but doesn't actually do that. Link: https://lkml.kernel.org/r/20210713055231.137602-3-hch@lst.de Fixes: 28961998f858 ("iov_iter: lift memzero_page() to highmem.h") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-23mm: call flush_dcache_page() in memcpy_to_page() and memzero_page()Christoph Hellwig
memcpy_to_page and memzero_page can write to arbitrary pages, which could be in the page cache or in high memory, so call flush_kernel_dcache_pages to flush the dcache. This is a problem when using these helpers on dcache challeneged architectures. Right now there are just a few users, chances are no one used the PC floppy driver, the aha1542 driver for an ISA SCSI HBA, and a few advanced and optional btrfs and ext4 features on those platforms yet since the conversion. Link: https://lkml.kernel.org/r/20210713055231.137602-2-hch@lst.de Fixes: bb90d4bc7b6a ("mm/highmem: Lift memcpy_[to|from]_page to core") Fixes: 28961998f858 ("iov_iter: lift memzero_page() to highmem.h") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-04arm64: mte: handle tags zeroing at page allocation timePeter Collingbourne
Currently, on an anonymous page fault, the kernel allocates a zeroed page and maps it in user space. If the mapping is tagged (PROT_MTE), set_pte_at() additionally clears the tags. It is, however, more efficient to clear the tags at the same time as zeroing the data on allocation. To avoid clearing the tags on any page (which may not be mapped as tagged), only do this if the vma flags contain VM_MTE. This requires introducing a new GFP flag that is used to determine whether to clear the tags. The DC GZVA instruction with a 0 top byte (and 0 tag) requires top-byte-ignore. Set the TCR_EL1.{TBI1,TBID1} bits irrespective of whether KASAN_HW is enabled. Signed-off-by: Peter Collingbourne <pcc@google.com> Co-developed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://linux-review.googlesource.com/id/Id46dc94e30fe11474f7e54f5d65e7658dbdddb26 Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20210602235230.3928842-4-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org>
2021-06-04mm: arch: remove indirection level in alloc_zeroed_user_highpage_movable()Peter Collingbourne
In an upcoming change we would like to add a flag to GFP_HIGHUSER_MOVABLE so that it would no longer be an OR of GFP_HIGHUSER and __GFP_MOVABLE. This poses a problem for alloc_zeroed_user_highpage_movable() which passes __GFP_MOVABLE into an arch-specific __alloc_zeroed_user_highpage() hook which ORs in GFP_HIGHUSER. Since __alloc_zeroed_user_highpage() is only ever called from alloc_zeroed_user_highpage_movable(), we can remove one level of indirection here. Remove __alloc_zeroed_user_highpage(), make alloc_zeroed_user_highpage_movable() the hook, and use GFP_HIGHUSER_MOVABLE in the hook implementations so that they will pick up the new flag that we are going to add. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/Ic6361c657b2cdcd896adbe0cf7cb5a7fbb1ed7bf Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210602235230.3928842-2-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org>
2021-05-05iov_iter: lift memzero_page() to highmem.hIra Weiny
Patch series "btrfs: Convert kmap/memset/kunmap to memzero_user()". Lifting memzero_user(), convert it to kmap_local_page() and then use it in btrfs. This patch (of 3): memzero_page() can replace the kmap/memset/kunmap pattern in other places in the code. While zero_user() has the same interface it is not the same call and its use should be limited and some of those calls may be better converted from zero_user() to memzero_page().[1] But that is not addressed in this series. Lift memzero_page() to highmem. [1] https://lore.kernel.org/lkml/CAHk-=wijdojzo56FzYqE5TOYw2Vws7ik3LEMGj9SPQaJJ+Z73Q@mail.gmail.com/ Link: https://lkml.kernel.org/r/20210309212137.2610186-1-ira.weiny@intel.com Link: https://lkml.kernel.org/r/20210309212137.2610186-2-ira.weiny@intel.com Signed-off-by: Ira Weiny <ira.weiny@intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David Sterba <dsterba@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-11mm/highmem: Add VM_BUG_ON() to mem*_page() callsIra Weiny
Add VM_BUG_ON bounds checks to ensure the newly lifted and created page memory operations do not result in corrupted data in neighbor pages.[1][2] [1] https://lore.kernel.org/lkml/20201210053502.GS1563847@iweiny-DESK2.sc.intel.com/ [2] https://lore.kernel.org/lkml/20210209110931.00f00e47d9a0529fcee2ff01@linux-foundation.org/ Suggested-by: Matthew Wilcox <willy@infradead.org> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-11mm/highmem: Introduce memcpy_page(), memmove_page(), and memset_page()Ira Weiny
3 more common kmap patterns are kmap/memcpy/kunmap, kmap/memmove/kunmap. and kmap/memset/kunmap. Add helper functions for those patterns which use kmap_local_page(). Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-11mm/highmem: Convert memcpy_[to|from]_page() to kmap_local_page()Ira Weiny
kmap_local_page() is more efficient and is well suited for these calls. Convert the kmap() to kmap_local_page() Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-02-11mm/highmem: Lift memcpy_[to|from]_page to coreIra Weiny
Working through a conversion to a call kmap_local_page() instead of kmap() revealed many places where the pattern kmap/memcpy/kunmap occurred. Eric Biggers, Matthew Wilcox, Christoph Hellwig, Dan Williams, and Al Viro all suggested putting this code into helper functions. Al Viro further pointed out that these functions already existed in the iov_iter code.[1] Various locations for the lifted functions were considered. Headers like mm.h or string.h seem ok but don't really portray the functionality well. pagemap.h made some sense but is for page cache functionality.[2] Another alternative would be to create a new header for the promoted memcpy functions, but it masks the fact that these are designed to copy to/from pages using the kernel direct mappings and complicates matters with a new header. Placing these functions in 'highmem.h' is suboptimal especially with the changes being proposed in the functionality of kmap. From a caller perspective including/using 'highmem.h' implies that the functions defined in that header are only required when highmem is in use which is increasingly not the case with modern processors. However, highmem.h is where all the current functions like this reside (zero_user(), clear_highpage(), clear_user_highpage(), copy_user_highpage(), and copy_highpage()). So it makes the most sense even though it is distasteful for some.[3] Lift memcpy_to_page() and memcpy_from_page() to pagemap.h. [1] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/ https://lore.kernel.org/lkml/20201013112544.GA5249@infradead.org/ [2] https://lore.kernel.org/lkml/20201208122316.GH7338@casper.infradead.org/ [3] https://lore.kernel.org/lkml/20201013200149.GI3576660@ZenIV.linux.org.uk/#t https://lore.kernel.org/lkml/20201208163814.GN1563847@iweiny-DESK2.sc.intel.com/ Cc: Boris Pismenny <borisp@mellanox.com> Cc: Or Gerlitz <gerlitz.or@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Suggested-by: Matthew Wilcox <willy@infradead.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Suggested-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-12-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: - a few random little subsystems - almost all of the MM patches which are staged ahead of linux-next material. I'll trickle to post-linux-next work in as the dependents get merged up. Subsystems affected by this patch series: kthread, kbuild, ide, ntfs, ocfs2, arch, and mm (slab-generic, slab, slub, dax, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, hmm, vmalloc, documentation, kasan, pagealloc, memory-failure, hugetlb, vmscan, z3fold, compaction, oom-kill, migration, cma, page-poison, userfaultfd, zswap, zsmalloc, uaccess, zram, and cleanups). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (200 commits) mm: cleanup kstrto*() usage mm: fix fall-through warnings for Clang mm: slub: convert sysfs sprintf family to sysfs_emit/sysfs_emit_at mm: shmem: convert shmem_enabled_show to use sysfs_emit_at mm:backing-dev: use sysfs_emit in macro defining functions mm: huge_memory: convert remaining use of sprintf to sysfs_emit and neatening mm: use sysfs_emit for struct kobject * uses mm: fix kernel-doc markups zram: break the strict dependency from lzo zram: add stat to gather incompressible pages since zram set up zram: support page writeback mm/process_vm_access: remove redundant initialization of iov_r mm/zsmalloc.c: rework the list_add code in insert_zspage() mm/zswap: move to use crypto_acomp API for hardware acceleration mm/zswap: fix passing zero to 'PTR_ERR' warning mm/zswap: make struct kernel_param_ops definitions const userfaultfd/selftests: hint the test runner on required privilege userfaultfd/selftests: fix retval check for userfaultfd_open() userfaultfd/selftests: always dump something in modes userfaultfd: selftests: make __{s,u}64 format specifiers portable ...
2020-12-15mm: support THPs in zero_user_segmentsMatthew Wilcox (Oracle)
We can only kmap() one subpage of a THP at a time, so loop over all relevant subpages, skipping ones which don't need to be zeroed. This is too large to inline when THPs are enabled and we actually need highmem, so put it in highmem.c. [willy@infradead.org: start1 was allowed to be less than start2] Link: https://lkml.kernel.org/r/20201124041507.28996-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Song Liu <songliubraving@fb.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-11-24mm/highmem: Provide kmap_local*Thomas Gleixner
Now that the kmap atomic index is stored in task struct provide a preemptible variant. On context switch the maps of an outgoing task are removed and the map of the incoming task are restored. That's obviously slow, but highmem is slow anyway. The kmap_local.*() functions can be invoked from both preemptible and atomic context. kmap local sections disable migration to keep the resulting virtual mapping address correct, but disable neither pagefaults nor preemption. A wholesale conversion of kmap_atomic to be fully preemptible is not possible because some of the usage sites might rely on the preemption disable for serialization or on the implicit pagefault disable. Needs to be done on a case by case basis. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20201118204007.468533059@linutronix.de
2020-11-06highmem: High implementation details and document APIThomas Gleixner
Move the gory details of kmap & al into a private header and only document the interfaces which are usable by drivers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20201103095858.827582066@linutronix.de
2020-11-06mm/highmem: Remove the old kmap_atomic cruftThomas Gleixner
All users gone. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20201103095858.516281567@linutronix.de
2020-11-06highmem: Get rid of kmap_types.hThomas Gleixner
The header is not longer used and on alpha, ia64, openrisc, parisc and um it was completely unused anyway as these architectures have no highmem support. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20201103095858.422094352@linutronix.de
2020-11-06x86/mm/highmem: Use generic kmap atomic implementationThomas Gleixner
Convert X86 to the generic kmap atomic implementation and make the iomap_atomic() naming convention consistent while at it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20201103095857.375127260@linutronix.de
2020-11-06highmem: Provide generic variant of kmap_atomic*Thomas Gleixner
The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations. Provide a generic variant for that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Link: https://lore.kernel.org/r/20201103095857.175939340@linutronix.de