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2021-04-30mm/kasan: switch from strlcpy to strscpyZhiyuan Dai
strlcpy is marked as deprecated in Documentation/process/deprecated.rst, and there is no functional difference when the caller expects truncation (when not checking the return value). strscpy is relatively better as it also avoids scanning the whole source string. Link: https://lkml.kernel.org/r/1613970647-23272-1-git-send-email-daizhiyuan@phytium.com.cn Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Acked-by: Alexander Potapenko <glider@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30pagewalk: prefix struct kernel-doc descriptionsLukas Bulwahn
The script './scripts/kernel-doc -none ./include/linux/pagewalk.h' reports: include/linux/pagewalk.h:37: warning: cannot understand function prototype: 'struct mm_walk_ops ' include/linux/pagewalk.h:85: warning: cannot understand function prototype: 'struct mm_walk ' A kernel-doc description for a structure requires to prefix the struct name with the keyword 'struct'. So, do that such that no further kernel-doc warnings are reported for this file. Link: https://lkml.kernel.org/r/20210322122542.15072-3-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30MAINTAINERS: assign pagewalk.h to MEMORY MANAGEMENTLukas Bulwahn
Patch series "kernel-doc and MAINTAINERS clean-up". Roughly 900 warnings of about 21.000 kernel-doc warnings in the kernel tree warn with 'cannot understand function prototype:', i.e., the kernel-doc parser cannot parse the function's signature. The majority, about 600 cases of those, are just struct definitions following the kernel-doc description. Further, spot-check investigations suggest that the authors of the specific kernel-doc descriptions simply were not aware that the general format for a kernel-doc description for a structure requires to prefix the struct name with the keyword 'struct', as in 'struct struct_name - Brief description.'. Details on kernel-doc are at the Link below. Without the struct keyword, kernel-doc does not check if the kernel-doc description fits to the actual struct definition in the source code. Fortunately, in roughly a quarter of these cases, the kernel-doc description is actually complete wrt. its corresponding struct definition. So, the trivial change adding the struct keyword will allow us to keep the kernel-doc descriptions more consistent for future changes, by checking for new kernel-doc warnings. Also, some of the files in ./include/ are not assigned to a specific MAINTAINERS section and hence have no dedicated maintainer. So, if needed, the files in ./include/ are also assigned to the fitting MAINTAINERS section, as I need to identify whom to send the clean-up patch anyway. Here is the change from this kernel-doc janitorial work in the ./include/ directory for MEMORY MANAGEMENT. This patch (of 2): Commit a520110e4a15 ("mm: split out a new pagewalk.h header from mm.h") adds a new file in ./include/linux, but misses to update MAINTAINERS accordingly. Hence, ./scripts/get_maintainers.pl include/linux/pagewalk.h points only to lkml as general fallback for all files, whereas the original include/linux/mm.h clearly marks this file part of MEMORY MANAGEMENT. Assign include/linux/pagewalk.h to MEMORY MANAGEMENT. Link: https://lkml.kernel.org/r/20210322122542.15072-1-lukas.bulwahn@gmail.com Link: https://lkml.kernel.org/r/20210322122542.15072-2-lukas.bulwahn@gmail.com Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Ralf Ramsauer <ralf.ramsauer@oth-regensburg.de> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/doc: add mm.h and mm_types.h to the mm-api documentMatthew Wilcox (Oracle)
kerneldoc in include/linux/mm.h and include/linux/mm_types.h wasn't being included in the html build. Link: https://lkml.kernel.org/r/20210322195022.2143603-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/doc: turn fault flags into an enumMatthew Wilcox (Oracle)
The kernel-doc script complains about include/linux/mm.h:425: warning: wrong kernel-doc identifier on line: * Fault flag definitions. I don't know how to document a series of #defines, so turn these definitions into an enum and document that instead. Link: https://lkml.kernel.org/r/20210322195022.2143603-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/doc: fix page_maybe_dma_pinned kerneldocMatthew Wilcox (Oracle)
make htmldocs reports: include/linux/mm.h:1341: warning: Excess function parameter 'Return' description in 'page_maybe_dma_pinned' Fix a few other formatting nits while I'm editing this description. Link: https://lkml.kernel.org/r/20210322195022.2143603-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/doc: fix fault_flag_allow_retry_first kerneldocMatthew Wilcox (Oracle)
make htmldocs reports: include/linux/mm.h:496: warning: Function parameter or member 'flags' not described in 'fault_flag_allow_retry_first' Add a description. Link: https://lkml.kernel.org/r/20210322195022.2143603-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: remove an empty lineUladzislau Rezki (Sony)
Link: https://lkml.kernel.org/r/20210402202237.20334-5-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: refactor the preloading loagicUladzislau Rezki (Sony)
Instead of keeping open-coded style, move the code related to preloading into a separate function. Therefore introduce the preload_this_cpu_lock() routine that prelaods a current CPU with one extra vmap_area object. There is no functional change as a result of this patch. Link: https://lkml.kernel.org/r/20210402202237.20334-4-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30vm/test_vmalloc.sh: adapt for updated driver interfaceUladzislau Rezki (Sony)
A 'single_cpu_test' parameter is odd and it does not exist anymore. Instead there was introduced a 'nr_threads' one. If it is not set it behaves as the former parameter. That is why update a "stress mode" according to this change specifying number of workers which are equal to number of CPUs. Also update an output of help message based on a new interface. Link: https://lkml.kernel.org/r/20210402202237.20334-3-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30lib/test_vmalloc.c: add a new 'nr_threads' parameterUladzislau Rezki (Sony)
By using this parameter we can specify how many workers are created to perform vmalloc tests. By default it is one CPU. The maximum value is set to 1024. As a result of this change a 'single_cpu_test' one becomes obsolete, therefore it is no longer needed. [urezki@gmail.com: extend max value of nr_threads parameter] Link: https://lkml.kernel.org/r/20210406124536.19658-1-urezki@gmail.com Link: https://lkml.kernel.org/r/20210402202237.20334-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30lib/test_vmalloc.c: remove two kvfree_rcu() testsUladzislau Rezki (Sony)
Remove two test cases related to kvfree_rcu() and SLAB. Those are considered as redundant now, because similar test functionality has recently been introduced in the "rcuscale" RCU test-suite. Link: https://lkml.kernel.org/r/20210402202237.20334-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: vmalloc: prevent use after free in _vm_unmap_aliasesVijayanand Jitta
A potential use after free can occur in _vm_unmap_aliases where an already freed vmap_area could be accessed, Consider the following scenario: Process 1 Process 2 __vm_unmap_aliases __vm_unmap_aliases purge_fragmented_blocks_allcpus rcu_read_lock() rcu_read_lock() list_del_rcu(&vb->free_list) list_for_each_entry_rcu(vb .. ) __purge_vmap_area_lazy kmem_cache_free(va) va_start = vb->va->va_start Here Process 1 is in purge path and it does list_del_rcu on vmap_block and later frees the vmap_area, since Process 2 was holding the rcu lock at this time vmap_block will still be present in and Process 2 accesse it and thereby it tries to access vmap_area of that vmap_block which was already freed by Process 1 and this results in use after free. Fix this by adding a check for vb->dirty before accessing vmap_area structure since vb->dirty will be set to VMAP_BBMAP_BITS in purge path checking for this will prevent the use after free. Link: https://lkml.kernel.org/r/1616062105-23263-1-git-send-email-vjitta@codeaurora.org Signed-off-by: Vijayanand Jitta <vjitta@codeaurora.org> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: improve allocation failure error messagesNicholas Piggin
There are several reasons why a vmalloc can fail, virtual space exhausted, page array allocation failure, page allocation failure, and kernel page table allocation failure. Add distinct warning messages for the main causes of failure, with some added information like page order or allocation size where applicable. [urezki@gmail.com: print correct vmalloc allocation size] Link: https://lkml.kernel.org/r/20210329193214.GA28602@pc638.lan Link: https://lkml.kernel.org/r/20210322021806.892164-6-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Cédric Le Goater <clg@kaod.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: remove unmap_kernel_rangeNicholas Piggin
This is a shim around vunmap_range, get rid of it. Move the main API comment from the _noflush variant to the normal variant, and make _noflush internal to mm/. [npiggin@gmail.com: fix nommu builds and a comment bug per sfr] Link: https://lkml.kernel.org/r/1617292598.m6g0knx24s.astroid@bobo.none [akpm@linux-foundation.org: move vunmap_range_noflush() stub inside !CONFIG_MMU, not !CONFIG_NUMA] [npiggin@gmail.com: fix nommu builds] Link: https://lkml.kernel.org/r/1617292497.o1uhq5ipxp.astroid@bobo.none Link: https://lkml.kernel.org/r/20210322021806.892164-5-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Cédric Le Goater <clg@kaod.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30powerpc/xive: remove unnecessary unmap_kernel_rangeNicholas Piggin
iounmap will remove ptes. Link: https://lkml.kernel.org/r/20210322021806.892164-4-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Cédric Le Goater <clg@kaod.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30kernel/dma: remove unnecessary unmap_kernel_rangeNicholas Piggin
vunmap will remove ptes. Link: https://lkml.kernel.org/r/20210322021806.892164-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Cédric Le Goater <clg@kaod.org> Cc: Uladzislau Rezki <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: remove map_kernel_rangeNicholas Piggin
Patch series "mm/vmalloc: cleanup after hugepage series", v2. Christoph pointed out some overdue cleanups required after the huge vmalloc series, and I had another failure error message improvement as well. This patch (of 5): This is a shim around vmap_pages_range, get rid of it. Move the main API comment from the _noflush variant to the normal variant, and make _noflush internal to mm/. Link: https://lkml.kernel.org/r/20210322021806.892164-1-npiggin@gmail.com Link: https://lkml.kernel.org/r/20210322021806.892164-2-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Cédric Le Goater <clg@kaod.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: hugepage vmalloc mappingsNicholas Piggin
Support huge page vmalloc mappings. Config option HAVE_ARCH_HUGE_VMALLOC enables support on architectures that define HAVE_ARCH_HUGE_VMAP and supports PMD sized vmap mappings. vmalloc will attempt to allocate PMD-sized pages if allocating PMD size or larger, and fall back to small pages if that was unsuccessful. Architectures must ensure that any arch specific vmalloc allocations that require PAGE_SIZE mappings (e.g., module allocations vs strict module rwx) use the VM_NOHUGE flag to inhibit larger mappings. This can result in more internal fragmentation and memory overhead for a given allocation, an option nohugevmalloc is added to disable at boot. [colin.king@canonical.com: fix read of uninitialized pointer area] Link: https://lkml.kernel.org/r/20210318155955.18220-1-colin.king@canonical.com Link: https://lkml.kernel.org/r/20210317062402.533919-14-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: add vmap_range_noflush variantNicholas Piggin
As a side-effect, the order of flush_cache_vmap() and arch_sync_kernel_mappings() calls are switched, but that now matches the other callers in this file. Link: https://lkml.kernel.org/r/20210317062402.533919-13-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: move vmap_range from mm/ioremap.c to mm/vmalloc.cNicholas Piggin
This is a generic kernel virtual memory mapper, not specific to ioremap. Code is unchanged other than making vmap_range non-static. Link: https://lkml.kernel.org/r/20210317062402.533919-12-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: provide fallback arch huge vmap support functionsNicholas Piggin
If an architecture doesn't support a particular page table level as a huge vmap page size then allow it to skip defining the support query function. Link: https://lkml.kernel.org/r/20210317062402.533919-11-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Suggested-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86: inline huge vmap supported functionsNicholas Piggin
This allows unsupported levels to be constant folded away, and so p4d_free_pud_page can be removed because it's no longer linked to. Link: https://lkml.kernel.org/r/20210317062402.533919-10-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30arm64: inline huge vmap supported functionsNicholas Piggin
This allows unsupported levels to be constant folded away, and so p4d_free_pud_page can be removed because it's no longer linked to. Link: https://lkml.kernel.org/r/20210317062402.533919-9-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30powerpc: inline huge vmap supported functionsNicholas Piggin
This allows unsupported levels to be constant folded away, and so p4d_free_pud_page can be removed because it's no longer linked to. Link: https://lkml.kernel.org/r/20210317062402.533919-8-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: HUGE_VMAP arch support cleanupNicholas Piggin
This changes the awkward approach where architectures provide init functions to determine which levels they can provide large mappings for, to one where the arch is queried for each call. This removes code and indirection, and allows constant-folding of dead code for unsupported levels. This also adds a prot argument to the arch query. This is unused currently but could help with some architectures (e.g., some powerpc processors can't map uncacheable memory with large pages). Link: https://lkml.kernel.org/r/20210317062402.533919-7-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Ding Tianhong <dingtianhong@huawei.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Will Deacon <will@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/ioremap: rename ioremap_*_range to vmap_*_rangeNicholas Piggin
This will be used as a generic kernel virtual mapping function, so re-name it in preparation. Link: https://lkml.kernel.org/r/20210317062402.533919-6-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: rename vmap_*_range vmap_pages_*_rangeNicholas Piggin
The vmalloc mapper operates on a struct page * array rather than a linear physical address, re-name it to make this distinction clear. Link: https://lkml.kernel.org/r/20210317062402.533919-5-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: apply_to_pte_range warn and fail if a large pte is encounteredNicholas Piggin
apply_to_pte_range might mistake a large pte for bad, or treat it as a page table, resulting in a crash or corruption. Add a test to warn and return error if large entries are found. Link: https://lkml.kernel.org/r/20210317062402.533919-4-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: fix HUGE_VMAP regression by enabling huge pages in vmalloc_to_pageNicholas Piggin
vmalloc_to_page returns NULL for addresses mapped by larger pages[*]. Whether or not a vmap is huge depends on the architecture details, alignments, boot options, etc., which the caller can not be expected to know. Therefore HUGE_VMAP is a regression for vmalloc_to_page. This change teaches vmalloc_to_page about larger pages, and returns the struct page that corresponds to the offset within the large page. This makes the API agnostic to mapping implementation details. [*] As explained by commit 029c54b095995 ("mm/vmalloc.c: huge-vmap: fail gracefully on unexpected huge vmap mappings") [npiggin@gmail.com: sparc32: add stub pud_page define for walking huge vmalloc page tables] Link: https://lkml.kernel.org/r/20210324232825.1157363-1-npiggin@gmail.com Link: https://lkml.kernel.org/r/20210317062402.533919-3-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30ARM: mm: add missing pud_page define to 2-level page tablesNicholas Piggin
Patch series "huge vmalloc mappings", v13. The kernel virtual mapping layer grew support for mapping memory with > PAGE_SIZE ptes with commit 0ddab1d2ed66 ("lib/ioremap.c: add huge I/O map capability interfaces"), and implemented support for using those huge page mappings with ioremap. According to the submission, the use-case is mapping very large non-volatile memory devices, which could be GB or TB: https://lore.kernel.org/lkml/1425404664-19675-1-git-send-email-toshi.kani@hp.com/ The benefit is said to be in the overhead of maintaining the mapping, perhaps both in memory overhead and setup / teardown time. Memory overhead for the mapping with a 4kB page and 8 byte page table is 2GB per TB of mapping, down to 4MB / TB with 2MB pages. The same huge page vmap infrastructure can be quite easily adapted and used for mapping vmalloc memory pages without more complexity for arch or core vmap code. However unlike ioremap, vmalloc page table overhead is not a real problem, so the advantage to justify this is performance. Several of the most structures in the kernel (e.g., vfs and network hash tables) are allocated with vmalloc on NUMA machines, in order to distribute access bandwidth over the machine. Mapping these with larger pages can improve TLB usage significantly, for example this reduces TLB misses by nearly 30x on a `git diff` workload on a 2-node POWER9 (59,800 -> 2,100) and reduces CPU cycles by 0.54%, due to vfs hashes being allocated with 2MB pages. [ Other numbers? - The difference is even larger in a guest due to more costly TLB misses. - Eric Dumazet was keen on the network hash performance possibilities. - Other archs? Ding was doing x86 testing. ] The kernel module allocator also uses vmalloc to map module images even on non-NUMA, which can result in high iTLB pressure on highly modular distro type of kernels. This series does not implement huge mappings for modules yet, but it's a step along the way. Rick Edgecombe was looking at that IIRC. The per-cpu allocator similarly might be able to take advantage of this. Also on the todo list. The disadvantages of this I can see are: * Memory fragmentation can waste some physical memory because it will attempt to allocate larger pages to fit the required size, rounding up (once the requested size is >= 2MB). - I don't see it being a big problem in practice unless some user crops up that allocates thousands of 2.5MB ranges. We can tewak heuristics a bit there if needed to reduce peak waste. * Less granular mappings can make the NUMA distribution less balanced. - Similar to the above. - Could also allocate all major system hashes with one allocation up-front and spread them all across the one block, which should help overall NUMA distribution and reduce fragmentation waste. * Callers might expect something about the underlying allocated pages. - Tried to keep the apperance of base PAGE_SIZE pages throughout the APIs and exposed data structures. - Added a VM_NO_HUGE_VMAP flag to hammer troublesome cases with. - Finally, added a nohugevmalloc boot option to turn it off (independent of nohugeiomap). This patch (of 14): ARM uses its own PMD folding scheme which is missing pud_page which should just pass through to pmd_page. Move this from the 3-level page table to common header. Link: https://lkml.kernel.org/r/20210317062402.533919-2-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/vmalloc: use rb_tree instead of list for vread() lookupsSerapheim Dimitropoulos
vread() has been linearly searching vmap_area_list for looking up vmalloc areas to read from. These same areas are also tracked by a rb_tree (vmap_area_root) which offers logarithmic lookup. This patch modifies vread() to use the rb_tree structure instead of the list and the speedup for heavy /proc/kcore readers can be pretty significant. Below are the wall clock measurements of a Python application that leverages the drgn debugging library to read and interpret data read from /proc/kcore. Before the patch: ----- $ time sudo sdb -e 'dbuf | head 3000 | wc' (unsigned long)3000 real 0m22.446s user 0m2.321s sys 0m20.690s ----- With the patch: ----- $ time sudo sdb -e 'dbuf | head 3000 | wc' (unsigned long)3000 real 0m2.104s user 0m2.043s sys 0m0.921s ----- Link: https://lkml.kernel.org/r/20210209190253.108763-1-serapheim@delphix.com Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: unexport remap_vmalloc_range_partialChristoph Hellwig
remap_vmalloc_range_partial is only used to implement remap_vmalloc_range and by procfs. Unexport it. Link: https://lkml.kernel.org/r/20210301082235.932968-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30samples/vfio-mdev/mdpy: use remap_vmalloc_rangeChristoph Hellwig
Patch series "remap_vmalloc_range cleanups". This series removes an open coded instance of remap_vmalloc_range and removes the unused remap_vmalloc_range_partial export. This patch (of 2): Use remap_vmalloc_range instead of open coding it using remap_vmalloc_range_partial. Link: https://lkml.kernel.org/r/20210301082235.932968-1-hch@lst.de Link: https://lkml.kernel.org/r/20210301082235.932968-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Kirti Wankhede <kwankhede@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/sparse: add the missing sparse_buffer_fini() in error branchWang Wensheng
sparse_buffer_init() and sparse_buffer_fini() should appear in pair, or a WARN issue would be through the next time sparse_buffer_init() runs. Add the missing sparse_buffer_fini() in error branch. Link: https://lkml.kernel.org/r/20210325113155.118574-1-wangwensheng4@huawei.com Fixes: 85c77f791390 ("mm/sparse: add new sparse_init_nid() and sparse_init()") Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/dmapool: switch from strlcpy to strscpyZhiyuan Dai
strlcpy is marked as deprecated in Documentation/process/deprecated.rst, and there is no functional difference when the caller expects truncation (when not checking the return value). strscpy is relatively better as it also avoids scanning the whole source string. Link: https://lkml.kernel.org/r/1613962050-14188-1-git-send-email-daizhiyuan@phytium.com.cn Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30selftests: add a MREMAP_DONTUNMAP selftest for shmemBrian Geffon
This test extends the current mremap tests to validate that the MREMAP_DONTUNMAP operation can be performed on shmem mappings. Link: https://lkml.kernel.org/r/20210323182520.2712101-3-bgeffon@google.com Signed-off-by: Brian Geffon <bgeffon@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Peter Xu <peterx@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: Brian Geffon <bgeffon@google.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Dmitry Safonov <dima@arista.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Alejandro Colomar <alx.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30Revert "mremap: don't allow MREMAP_DONTUNMAP on special_mappings and aio"Brian Geffon
This reverts commit cd544fd1dc9293c6702fab6effa63dac1cc67e99. As discussed in [1] this commit was a no-op because the mapping type was checked in vma_to_resize before move_vma is ever called. This meant that vm_ops->mremap() would never be called on such mappings. Furthermore, we've since expanded support of MREMAP_DONTUNMAP to non-anonymous mappings, and these special mappings are still protected by the existing check of !VM_DONTEXPAND and !VM_PFNMAP which will result in a -EINVAL. 1. https://lkml.org/lkml/2020/12/28/2340 Link: https://lkml.kernel.org/r/20210323182520.2712101-2-bgeffon@google.com Signed-off-by: Brian Geffon <bgeffon@google.com> Acked-by: Hugh Dickins <hughd@google.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Alejandro Colomar <alx.manpages@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Lokesh Gidra <lokeshgidra@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: extend MREMAP_DONTUNMAP to non-anonymous mappingsBrian Geffon
Patch series "mm: Extend MREMAP_DONTUNMAP to non-anonymous mappings", v5. This patch (of 3): Currently MREMAP_DONTUNMAP only accepts private anonymous mappings. This restriction was placed initially for simplicity and not because there exists a technical reason to do so. This change will widen the support to include any mappings which are not VM_DONTEXPAND or VM_PFNMAP. The primary use case is to support MREMAP_DONTUNMAP on mappings which may have been created from a memfd. This change will result in mremap(MREMAP_DONTUNMAP) returning -EINVAL if VM_DONTEXPAND or VM_PFNMAP mappings are specified. Lokesh Gidra who works on the Android JVM, provided an explanation of how such a feature will improve Android JVM garbage collection: "Android is developing a new garbage collector (GC), based on userfaultfd. The garbage collector will use userfaultfd (uffd) on the java heap during compaction. On accessing any uncompacted page, the application threads will find it missing, at which point the thread will create the compacted page and then use UFFDIO_COPY ioctl to get it mapped and then resume execution. Before starting this compaction, in a stop-the-world pause the heap will be mremap(MREMAP_DONTUNMAP) so that the java heap is ready to receive UFFD_EVENT_PAGEFAULT events after resuming execution. To speedup mremap operations, pagetable movement was optimized by moving PUD entries instead of PTE entries [1]. It was necessary as mremap of even modest sized memory ranges also took several milliseconds, and stopping the application for that long isn't acceptable in response-time sensitive cases. With UFFDIO_CONTINUE feature [2], it will be even more efficient to implement this GC, particularly the 'non-moveable' portions of the heap. It will also help in reducing the need to copy (UFFDIO_COPY) the pages. However, for this to work, the java heap has to be on a 'shared' vma. Currently MREMAP_DONTUNMAP only supports private anonymous mappings, this patch will enable using UFFDIO_CONTINUE for the new userfaultfd-based heap compaction." [1] https://lore.kernel.org/linux-mm/20201215030730.NC3CU98e4%25akpm@linux-foundation.org/ [2] https://lore.kernel.org/linux-mm/20210302000133.272579-1-axelrasmussen@google.com/ Link: https://lkml.kernel.org/r/20210323182520.2712101-1-bgeffon@google.com Signed-off-by: Brian Geffon <bgeffon@google.com> Acked-by: Hugh Dickins <hughd@google.com> Tested-by: Lokesh Gidra <lokeshgidra@google.com> Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com> Cc: Alejandro Colomar <alx.manpages@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Michael S . Tsirkin" <mst@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Sonny Rao <sonnyrao@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30NUMA balancing: reduce TLB flush via delaying mapping on hint page faultHuang Ying
With NUMA balancing, in hint page fault handler, the faulting page will be migrated to the accessing node if necessary. During the migration, TLB will be shot down on all CPUs that the process has run on recently. Because in the hint page fault handler, the PTE will be made accessible before the migration is tried. The overhead of TLB shooting down can be high, so it's better to be avoided if possible. In fact, if we delay mapping the page until migration, that can be avoided. This is what this patch doing. For the multiple threads applications, it's possible that a page is accessed by multiple threads almost at the same time. In the original implementation, because the first thread will install the accessible PTE before migrating the page, the other threads may access the page directly before the page is made inaccessible again during migration. While with the patch, the second thread will go through the page fault handler too. And because of the PageLRU() checking in the following code path, migrate_misplaced_page() numamigrate_isolate_page() isolate_lru_page() the migrate_misplaced_page() will return 0, and the PTE will be made accessible in the second thread. This will introduce a little more overhead. But we think the possibility for a page to be accessed by the multiple threads at the same time is low, and the overhead difference isn't too large. If this becomes a problem in some workloads, we need to consider how to reduce the overhead. To test the patch, we run a test case as follows on a 2-socket Intel server (1 NUMA node per socket) with 128GB DRAM (64GB per socket). 1. Run a memory eater on NUMA node 1 to use 40GB memory before running pmbench. 2. Run pmbench (normal accessing pattern) with 8 processes, and 8 threads per process, so there are 64 threads in total. The working-set size of each process is 8960MB, so the total working-set size is 8 * 8960MB = 70GB. The CPU of all pmbench processes is bound to node 1. The pmbench processes will access some DRAM on node 0. 3. After the pmbench processes run for 10 seconds, kill the memory eater. Now, some pages will be migrated from node 0 to node 1 via NUMA balancing. Test results show that, with the patch, the pmbench throughput (page accesses/s) increases 5.5%. The number of the TLB shootdowns interrupts reduces 98% (from ~4.7e7 to ~9.7e5) with about 9.2e6 pages (35.8GB) migrated. From the perf profile, it can be found that the CPU cycles spent by try_to_unmap() and its callees reduces from 6.02% to 0.47%. That is, the CPU cycles spent by TLB shooting down decreases greatly. Link: https://lkml.kernel.org/r/20210408132236.1175607-1-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Matthew Wilcox" <willy@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Michel Lespinasse <walken@google.com> Cc: Arjun Roy <arjunroy@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30i915: fix remap_io_sg to verify the pgprotChristoph Hellwig
remap_io_sg claims that the pgprot is pre-verified using an io_mapping, but actually does not get passed an io_mapping and just uses the pgprot in the VMA. Remove the apply_to_page_range abuse and just loop over remap_pfn_range for each segment. Note: this could use io_mapping_map_user by passing an iomap to remap_io_sg if the maintainers can verify that the pgprot in the iomap in the only caller is indeed the desired one here. Link: https://lkml.kernel.org/r/20210326055505.1424432-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30i915: use io_mapping_map_userChristoph Hellwig
Replace the home-grown remap_io_mapping that abuses apply_to_page_range with the proper io_mapping_map_user interface. Link: https://lkml.kernel.org/r/20210326055505.1424432-4-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: add a io_mapping_map_user helperChristoph Hellwig
Add a helper that calls remap_pfn_range for an struct io_mapping, relying on the pgprot pre-validation done when creating the mapping instead of doing it at runtime. Link: https://lkml.kernel.org/r/20210326055505.1424432-3-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm: add remap_pfn_range_notrackChristoph Hellwig
Patch series "add remap_pfn_range_notrack instead of reinventing it in i915", v2. i915 has some reason to want to avoid the track_pfn_remap overhead in remap_pfn_range. Add a function to the core VM to do just that rather than reinventing the functionality poorly in the driver. Note that the remap_io_sg path does get exercises when using Xorg on my Thinkpad X1, so this should be considered lightly tested, I've not managed to hit the remap_io_mapping path at all. This patch (of 4): Add a version of remap_pfn_range that does not call track_pfn_range. This will be used to fix horrible abuses of VM internals in the i915 driver. Link: https://lkml.kernel.org/r/20210326055505.1424432-1-hch@lst.de Link: https://lkml.kernel.org/r/20210326055505.1424432-2-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm, tracing: improve rss_stat tracepoint messageOvidiu Panait
Adjust the rss_stat tracepoint to print the name of the resident page type that got updated (e.g. MM_ANONPAGES/MM_FILEPAGES), rather than the numeric index corresponding to it (the __entry->member value): Before this patch: ------------------ rss_stat: mm_id=1216113068 curr=0 member=1 size=28672B rss_stat: mm_id=1216113068 curr=0 member=1 size=0B rss_stat: mm_id=534402304 curr=1 member=0 size=188416B rss_stat: mm_id=534402304 curr=1 member=1 size=40960B After this patch: ----------------- rss_stat: mm_id=1726253524 curr=1 type=MM_ANONPAGES size=40960B rss_stat: mm_id=1726253524 curr=1 type=MM_FILEPAGES size=663552B rss_stat: mm_id=1726253524 curr=1 type=MM_ANONPAGES size=65536B rss_stat: mm_id=1726253524 curr=1 type=MM_FILEPAGES size=647168B Use TRACE_DEFINE_ENUM()/__print_symbolic() logic to map the enum values to the strings they represent, so that userspace tools can also parse the raw data correctly. Link: https://lkml.kernel.org/r/20210310162305.4862-1-ovidiu.panait@windriver.com Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com> Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: optimize for consecutive sections in partial populated PMDsOscar Salvador
We can optimize in the case we are adding consecutive sections, so no memset(PAGE_UNUSED) is needed. In that case, let us keep track where the unused range of the previous memory range begins, so we can compare it with start of the range to be added. If they are equal, we know sections are added consecutively. For that purpose, let us introduce 'unused_pmd_start', which always holds the beginning of the unused memory range. In the case a section does not contiguously follow the previous one, we know we can memset [unused_pmd_start, PMD_BOUNDARY) with PAGE_UNUSE. This patch is based on a similar patch by David Hildenbrand: https://lore.kernel.org/linux-mm/20200722094558.9828-10-david@redhat.com/ Link: https://lkml.kernel.org/r/20210309214050.4674-5-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: handle unpopulated sub-pmd rangesOscar Salvador
When sizeof(struct page) is not a power of 2, sections do not span a PMD anymore and so when populating them some parts of the PMD will remain unused. Because of this, PMDs will be left behind when depopulating sections since remove_pmd_table() thinks that those unused parts are still in use. Fix this by marking the unused parts with PAGE_UNUSED, so memchr_inv() will do the right thing and will let us free the PMD when the last user of it is gone. This patch is based on a similar patch by David Hildenbrand: https://lore.kernel.org/linux-mm/20200722094558.9828-9-david@redhat.com/ [osalvador@suse.de: go back to the ifdef version] Link: https://lkml.kernel.org/r/YGy++mSft7K4u+88@localhost.localdomain Link: https://lkml.kernel.org/r/20210309214050.4674-4-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: drop handling of 1GB vmemmap rangesOscar Salvador
There is no code to allocate 1GB pages when mapping the vmemmap range as this might waste some memory and requires more complexity which is not really worth. Drop the dead code both for the aligned and unaligned cases and leave only the direct map handling. Link: https://lkml.kernel.org/r/20210309214050.4674-3-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30x86/vmemmap: drop handling of 4K unaligned vmemmap rangeOscar Salvador
Patch series "Cleanup and fixups for vmemmap handling", v6. This series contains cleanups to remove dead code that handles unaligned cases for 4K and 1GB pages (patch#1 and patch#2) when removing the vemmmap range, and a fix (patch#3) to handle the case when two vmemmap ranges intersect the same PMD. This patch (of 4): remove_pte_table() is prepared to handle the case where either the start or the end of the range is not PAGE aligned. This cannot actually happen: __populate_section_memmap enforces the range to be PMD aligned, so as long as the size of the struct page remains multiple of 8, the vmemmap range will be aligned to PAGE_SIZE. Drop the dead code and place a VM_BUG_ON in vmemmap_{populate,free} to catch nasty cases. Note that the VM_BUG_ON is placed in there because vmemmap_{populate,free= } is the gate of all removing and freeing page tables logic. Link: https://lkml.kernel.org/r/20210309214050.4674-1-osalvador@suse.de Link: https://lkml.kernel.org/r/20210309214050.4674-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-30mm/interval_tree: add comments to improve code readabilityZhiyuan Dai
Add a comment explaining the value of the ISSTATIC parameter, Inform the reader that this is not a coding style issue. Link: https://lkml.kernel.org/r/1613964695-17614-1-git-send-email-daizhiyuan@phytium.com.cn Signed-off-by: Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>