- 12 Jul, 2019 40 commits
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Mike Rapoport authored
The only difference between the generic and RISC-V implementation of PTE allocation is the usage of __GFP_RETRY_MAYFAIL for both kernel and user PTEs and the absence of __GFP_ACCOUNT for the user PTEs. The conversion to the generic version removes the __GFP_RETRY_MAYFAIL and ensures that GFP_ACCOUNT is used for the user PTE allocations. The pte_free() and pte_free_kernel() versions are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-13-git-send-email-rppt@linux.ibm.comSigned-off-by:
Mike Rapoport <rppt@linux.ibm.com> Reviewed-by:
Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Mike Rapoport authored
parisc allocates PTE pages with __get_free_page() and uses GFP_KERNEL | __GFP_ZERO for the allocations. Switch it to the generic version that does exactly the same thing for the kernel page tables and adds __GFP_ACCOUNT for the user PTEs. The pte_free_kernel() and pte_free() versions on are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-12-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Mike Rapoport authored
nios2 allocates kernel PTE pages with __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTE_ORDER); and user page tables with pte = alloc_pages(GFP_KERNEL, PTE_ORDER); if (pte) clear_highpage(); The PTE_ORDER is hardwired to zero, which makes nios2 implementation almost identical to the generic one. Switch nios2 to the generic version that does exactly the same thing for the kernel page tables and adds __GFP_ACCOUNT for the user PTEs. The pte_free_kernel() and pte_free() versions on nios2 are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-11-git-send-email-rppt@linux.ibm.comSigned-off-by: -
Mike Rapoport authored
The nds32 implementation of pte_alloc_one_kernel() differs from the generic in the use of __GFP_RETRY_MAYFAIL flag, which is removed after the conversion. The nds32 version of pte_alloc_one() missed the call to pgtable_page_ctor() and also used __GFP_RETRY_MAYFAIL. Switching it to use generic __pte_alloc_one() for the PTE page allocation ensures that page table constructor is run and the user page tables are allocated with __GFP_ACCOUNT. The conversion to the generic version of pte_free_kernel() removes the NULL check for pte. The pte_free() version on nds32 is identical to the generic one and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-10-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Mike Rapoport authored
MIPS allocates kernel PTE pages with __get_free_pages(GFP_KERNEL | __GFP_ZERO, PTE_ORDER) and user PTE pages with pte = alloc_pages(GFP_KERNEL, PTE_ORDER) and then uses clear_highpage(pte) to zero out the allocated page for the user page tables. The PTE_ORDER is hardwired to zero, which makes MIPS implementation almost identical to the generic one. Switch MIPS to the generic version that does exactly the same thing for the kernel page tables and adds __GFP_ACCOUNT for the user PTEs. The pte_free_kernel() and pte_free() versions on mips are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-9-git-send-email-rppt@linux.ibm.comSigned-off-by:
Paul Burton <paul.burton@mips.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Guo Ren <ren_guo@c-sky.com> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by:
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Mike Rapoport authored
The sun3 MMU variant of m68k uses GFP_KERNEL to allocate a PTE page and then memset(0) or clear_highpage() to clear it. This is equivalent to allocating the page with GFP_KERNEL | __GFP_ZERO, which allows replacing sun3 implementation of pte_alloc_one() and pte_alloc_one_kernel() with the generic ones. The pte_free() and pte_free_kernel() versions are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-8-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Mike Rapoport authored
The csky implementation pte_alloc_one(), pte_free_kernel() and pte_free() is identical to the generic except of lack of __GFP_ACCOUNT for the user PTEs allocation. Switch csky to use generic version of these functions. The csky implementation of pte_alloc_one_kernel() is not replaced because it does not clear the allocated page but rather sets each PTE in it to a non-zero value. The pte_free_kernel() and pte_free() versions on csky are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-6-git-send-email-rppt@linux.ibm.comSigned-off-by:
Guo Ren <ren_guo@c-sky.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Ley Foon Tan <lftan@altera.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Sam Creasey <sammy@sammy.net> Cc: Vincent Chen <deanbo422@gmail.com> Signed-off-by:
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Mike Rapoport authored
The PTE allocations in arm64 are identical to the generic ones modulo the GFP flags. Using the generic pte_alloc_one() functions ensures that the user page tables are allocated with __GFP_ACCOUNT set. The arm64 definition of PGALLOC_GFP is removed and replaced with GFP_PGTABLE_USER for p[gum]d_alloc_one() for the user page tables and GFP_PGTABLE_KERNEL for the kernel page tables. The KVM memory cache is now using GFP_PGTABLE_USER. The mappings created with create_pgd_mapping() are now using GFP_PGTABLE_KERNEL. The conversion to the generic version of pte_free_kernel() removes the NULL check for pte. The pte_free() version on arm64 is identical to the generic one and can be simply dropped. [cai@lca.pw: fix a bogus GFP flag in pgd_alloc()] Link: https://lore.kernel.org/r/1559656836-24940-1-git-send-email-cai@lca.pw/ [and fix it more] Link: https://lore.kernel.org/linux-mm/20190617151252.GF16810@rapoport-lnx/ Link: http://lkml.kernel.org/r/1557296232-15361-5-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Mike Rapoport authored
Replace __get_free_page() and alloc_pages() calls with the generic __pte_alloc_one_kernel() and __pte_alloc_one(). There is no functional change for the kernel PTE allocation. The difference for the user PTEs, is that the clear_pte_table() is now called after pgtable_page_ctor() and the addition of __GFP_ACCOUNT to the GFP flags. The conversion to the generic version of pte_free_kernel() removes the NULL check for pte. The pte_free() version on arm is identical to the generic one and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-4-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Mike Rapoport authored
alpha allocates PTE pages with __get_free_page() and uses GFP_KERNEL | __GFP_ZERO for the allocations. Switch it to the generic version that does exactly the same thing for the kernel page tables and adds __GFP_ACCOUNT for the user PTEs. The alpha pte_free() and pte_free_kernel() versions are identical to the generic ones and can be simply dropped. Link: http://lkml.kernel.org/r/1557296232-15361-3-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Mike Rapoport authored
Most architectures have identical or very similar implementation of pte_alloc_one_kernel(), pte_alloc_one(), pte_free_kernel() and pte_free(). Add a generic implementation that can be reused across architectures and enable its use on x86. The generic implementation uses GFP_KERNEL | __GFP_ZERO for the kernel page tables and GFP_KERNEL | __GFP_ZERO | __GFP_ACCOUNT for the user page tables. The "base" functions for PTE allocation, namely __pte_alloc_one_kernel() and __pte_alloc_one() are intended for the architectures that require additional actions after actual memory allocation or must use non-default GFP flags. x86 is switched to use generic pte_alloc_one_kernel(), pte_free_kernel() and pte_free(). x86 still implements pte_alloc_one() to allow run-time control of GFP flags required for "userpte" command line option. Link: http://lkml.kernel.org/r/1557296232-15361-2-git-send-email-rppt@linux.ibm.comSigned-off-by:
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Guenter Roeck authored
Several mips builds generate the following build warning. mm/gup.c:1788:13: warning: 'undo_dev_pagemap' defined but not used The function is declared unconditionally but only called from behind various ifdefs. Mark it __maybe_unused. Link: http://lkml.kernel.org/r/1562072523-22311-1-git-send-email-linux@roeck-us.netSigned-off-by:
Guenter Roeck <linux@roeck-us.net> Reviewed-by:
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Andy Lutomirski authored
If we end up without a PGD or PUD entry backing the gate area, don't BUG -- just fail gracefully. It's not entirely implausible that this could happen some day on x86. It doesn't right now even with an execute-only emulated vsyscall page because the fixmap shares the PUD, but the core mm code shouldn't rely on that particular detail to avoid OOPSing. Link: http://lkml.kernel.org/r/a1d9f4efb75b9d464e59fd6af00104b21c58f6f7.1561610798.git.luto@kernel.orgSigned-off-by:
Andy Lutomirski <luto@kernel.org> Reviewed-by:
Kees Cook <keescook@chromium.org> Reviewed-by:
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Pingfan Liu authored
Both hugetlb and thp locate on the same migration type of pageblock, since they are allocated from a free_list[]. Based on this fact, it is enough to check on a single subpage to decide the migration type of the whole huge page. By this way, it saves (2M/4K - 1) times loop for pmd_huge on x86, similar on other archs. Furthermore, when executing isolate_huge_page(), it avoid taking global hugetlb_lock many times, and meanless remove/add to the local link list cma_page_list. [akpm@linux-foundation.org: make `i' and `step' unsigned] Link: http://lkml.kernel.org/r/1561612545-28997-1-git-send-email-kernelfans@gmail.comSigned-off-by:
Pingfan Liu <kernelfans@gmail.com> Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Keith Busch <keith.busch@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Christoph Hellwig authored
All other get_user_page_fast cases mark the page referenced, so do this here as well. Link: http://lkml.kernel.org/r/20190625143715.1689-17-hch@lst.deSigned-off-by:
Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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Christoph Hellwig authored
This applies the overflow fixes from 8fde12ca ("mm: prevent get_user_pages() from overflowing page refcount") to the powerpc hugepd code and brings it back in sync with the other GUP cases. Link: http://lkml.kernel.org/r/20190625143715.1689-16-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
While only powerpc supports the hugepd case, the code is pretty generic and I'd like to keep all GUP internals in one place. Link: http://lkml.kernel.org/r/20190625143715.1689-15-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
We can only deal with FOLL_WRITE and/or FOLL_LONGTERM in get_user_pages_fast, so reject all other flags. Link: http://lkml.kernel.org/r/20190625143715.1689-14-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Always build mm/gup.c so that we don't have to provide separate nommu stubs. Also merge the get_user_pages_fast and __get_user_pages_fast stubs when HAVE_FAST_GUP into the main implementations, which will never call the fast path if HAVE_FAST_GUP is not set. This also ensures the new put_user_pages* helpers are available for nommu, as those are currently missing, which would create a problem as soon as we actually grew users for it. Link: http://lkml.kernel.org/r/20190625143715.1689-13-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
This moves the actually exported functions towards the end of the file, and reorders some functions to be in more logical blocks as a preparation for moving various stubs inline into the main functionality using IS_ENABLED(). Link: http://lkml.kernel.org/r/20190625143715.1689-12-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
We only support the generic GUP now, so rename the config option to be more clear, and always use the mm/Kconfig definition of the symbol and select it from the arch Kconfigs. Link: http://lkml.kernel.org/r/20190625143715.1689-11-hch@lst.deSigned-off-by:
Khalid Aziz <khalid.aziz@oracle.com> Reviewed-by:
Jason Gunthorpe <jgg@mellanox.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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Christoph Hellwig authored
The sparc64 code is mostly equivalent to the generic one, minus various bugfixes and two arch overrides that this patch adds to pgtable.h. Link: http://lkml.kernel.org/r/20190625143715.1689-10-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Add a helper to untag a user pointer. This is needed for ADI support in get_user_pages_fast. Link: http://lkml.kernel.org/r/20190625143715.1689-9-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
sparc64 only had pgd_page_vaddr, but not pgd_page. [hch@lst.de: fix sparc64 build] Link: http://lkml.kernel.org/r/20190626131318.GA5101@lst.de Link: http://lkml.kernel.org/r/20190625143715.1689-8-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
The sh code is mostly equivalent to the generic one, minus various bugfixes and two arch overrides that this patch adds to pgtable.h. Link: http://lkml.kernel.org/r/20190625143715.1689-7-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
sh only had pud_page_vaddr, but not pud_page. [hch@lst.de: sh: stub out pud_page] Link: http://lkml.kernel.org/r/20190701151818.32227-2-hch@lst.de Link: http://lkml.kernel.org/r/20190625143715.1689-6-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
The mips code is mostly equivalent to the generic one, minus various bugfixes and an arch override for gup_fast_permitted. Note that this defines ARCH_HAS_PTE_SPECIAL for mips as mips has pte_special and pte_mkspecial implemented and used in the existing gup code. They are no-op stubs, though which makes me a little unsure if this is really right thing to do. Note that this also adds back a missing cpu_has_dc_aliases check for __get_user_pages_fast, which the old code was only doing for get_user_pages_fast. This clearly looks like an oversight, as any condition that makes get_user_pages_fast unsafe also applies to __get_user_pages_fast. [hch@lst.de: MIPS: don't select ARCH_HAS_PTE_SPECIAL] Link: http://lkml.kernel.org/r/20190701151818.32227-3-hch@lst.de Link: http://lkml.kernel.org/r/20190625143715.1689-5-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
The split low/high access is the only non-READ_ONCE version of gup_get_pte that did show up in the various arch implemenations. Lift it to common code and drop the ifdef based arch override. Link: http://lkml.kernel.org/r/20190625143715.1689-4-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Pass in the already calculated end value instead of recomputing it, and leave the end > start check in the callers instead of duplicating them in the arch code. Link: http://lkml.kernel.org/r/20190625143715.1689-3-hch@lst.deSigned-off-by:
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Christoph Hellwig authored
Patch series "switch the remaining architectures to use generic GUP", v4. A series to switch mips, sh and sparc64 to use the generic GUP code so that we only have one codebase to touch for further improvements to this code. This patch (of 16): This will allow sparc64, or any future architecture with memory tagging to override its tags for get_user_pages and get_user_pages_fast. Link: http://lkml.kernel.org/r/20190625143715.1689-2-hch@lst.deSigned-off-by:
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Waiman Long authored
There are concerns about memory leaks from extensive use of memory cgroups as each memory cgroup creates its own set of kmem caches. There is a possiblity that the memcg kmem caches may remain even after the memory cgroups have been offlined. Therefore, it will be useful to show the status of each of memcg kmem caches. This patch introduces a new <debugfs>/memcg_slabinfo file which is somewhat similar to /proc/slabinfo in format, but lists only information about kmem caches that have child memcg kmem caches. Information available in /proc/slabinfo are not repeated in memcg_slabinfo. A portion of a sample output of the file was: # <name> <css_id[:dead]> <active_objs> <num_objs> <active_slabs> <num_slabs> rpc_inode_cache root 13 51 1 1 rpc_inode_cache 48 0 0 0 0 fat_inode_cache root 1 45 1 1 fat_inode_cache 41 2 45 1 1 xfs_inode root 770 816 24 24 xfs_inode 92 22 34 1 1 xfs_inode 88:dead 1 34 1 1 xfs_inode 89:dead 23 34 1 1 xfs_inode 85 4 34 1 1 xfs_inode 84 9 34 1 1 The css id of the memcg is also listed. If a memcg is not online, the tag ":dead" will be attached as shown above. [longman@redhat.com: memcg: add ":deact" tag for reparented kmem caches in memcg_slabinfo] Link: http://lkml.kernel.org/r/20190621173005.31514-1-longman@redhat.com [longman@redhat.com: set the flag in the common code as suggested by Roman] Link: http://lkml.kernel.org/r/20190627184324.5875-1-longman@redhat.com Link: http://lkml.kernel.org/r/20190619171621.26209-1-longman@redhat.comSigned-off-by:
Waiman Long <longman@redhat.com> Suggested-by:
Shakeel Butt <shakeelb@google.com> Reviewed-by:
Roman Gushchin <guro@fb.com> Acked-by:
David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by:
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Roman Gushchin authored
Let's reparent non-root kmem_caches on memcg offlining. This allows us to release the memory cgroup without waiting for the last outstanding kernel object (e.g. dentry used by another application). Since the parent cgroup is already charged, everything we need to do is to splice the list of kmem_caches to the parent's kmem_caches list, swap the memcg pointer, drop the css refcounter for each kmem_cache and adjust the parent's css refcounter. Please, note that kmem_cache->memcg_params.memcg isn't a stable pointer anymore. It's safe to read it under rcu_read_lock(), cgroup_mutex held, or any other way that protects the memory cgroup from being released. We can race with the slab allocation and deallocation paths. It's not a big problem: parent's charge and slab global stats are always correct, and we don't care anymore about the child usage and global stats. The child cgroup is already offline, so we don't use or show it anywhere. Local slab stats (NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE) aren't used anywhere except count_shadow_nodes(). But even there it won't break anything: after reparenting "nodes" will be 0 on child level (because we're already reparenting shrinker lists), and on parent level page stats always were 0, and this patch won't change anything. [guro@fb.com: properly handle kmem_caches reparented to root_mem_cgroup] Link: http://lkml.kernel.org/r/20190620213427.1691847-1-guro@fb.com Link: http://lkml.kernel.org/r/20190611231813.3148843-11-guro@fb.comSigned-off-by:
Vladimir Davydov <vdavydov.dev@gmail.com> Reviewed-by:
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Roman Gushchin authored
Every slab page charged to a non-root memory cgroup has a pointer to the memory cgroup and holds a reference to it, which protects a non-empty memory cgroup from being released. At the same time the page has a pointer to the corresponding kmem_cache, and also hold a reference to the kmem_cache. And kmem_cache by itself holds a reference to the cgroup. So there is clearly some redundancy, which allows to stop setting the page->mem_cgroup pointer and rely on getting memcg pointer indirectly via kmem_cache. Further it will allow to change this pointer easier, without a need to go over all charged pages. So let's stop setting page->mem_cgroup pointer for slab pages, and stop using the css refcounter directly for protecting the memory cgroup from going away. Instead rely on kmem_cache as an intermediate object. Make sure that vmstats and shrinker lists are working as previously, as well as /proc/kpagecgroup interface. Link: http://lkml.kernel.org/r/20190611231813.3148843-10-guro@fb.comSigned-off-by:
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Roman Gushchin authored
Currently each charged slab page holds a reference to the cgroup to which it's charged. Kmem_caches are held by the memcg and are released all together with the memory cgroup. It means that none of kmem_caches are released unless at least one reference to the memcg exists, which is very far from optimal. Let's rework it in a way that allows releasing individual kmem_caches as soon as the cgroup is offline, the kmem_cache is empty and there are no pending allocations. To make it possible, let's introduce a new percpu refcounter for non-root kmem caches. The counter is initialized to the percpu mode, and is switched to the atomic mode during kmem_cache deactivation. The counter is bumped for every charged page and also for every running allocation. So the kmem_cache can't be released unless all allocations complete. To shutdown non-active empty kmem_caches, let's reuse the work queue, previously used for the kmem_cache deactivation. Once the reference counter reaches 0, let's schedule an asynchronous kmem_cache release. * I used the following simple approach to test the performance (stolen from another patchset by T. Harding): time find / -name fname-no-exist echo 2 > /proc/sys/vm/drop_caches repeat 10 times Results: orig patched real 0m1.455s real 0m1.355s user 0m0.206s user 0m0.219s sys 0m0.855s sys 0m0.807s real 0m1.487s real 0m1.699s user 0m0.221s user 0m0.256s sys 0m0.806s sys 0m0.948s real 0m1.515s real 0m1.505s user 0m0.183s user 0m0.215s sys 0m0.876s sys 0m0.858s real 0m1.291s real 0m1.380s user 0m0.193s user 0m0.198s sys 0m0.843s sys 0m0.786s real 0m1.364s real 0m1.374s user 0m0.180s user 0m0.182s sys 0m0.868s sys 0m0.806s real 0m1.352s real 0m1.312s user 0m0.201s user 0m0.212s sys 0m0.820s sys 0m0.761s real 0m1.302s real 0m1.349s user 0m0.205s user 0m0.203s sys 0m0.803s sys 0m0.792s real 0m1.334s real 0m1.301s user 0m0.194s user 0m0.201s sys 0m0.806s sys 0m0.779s real 0m1.426s real 0m1.434s user 0m0.216s user 0m0.181s sys 0m0.824s sys 0m0.864s real 0m1.350s real 0m1.295s user 0m0.200s user 0m0.190s sys 0m0.842s sys 0m0.811s So it looks like the difference is not noticeable in this test. [cai@lca.pw: fix an use-after-free in kmemcg_workfn()] Link: http://lkml.kernel.org/r/1560977573-10715-1-git-send-email-cai@lca.pw Link: http://lkml.kernel.org/r/20190611231813.3148843-9-guro@fb.comSigned-off-by:Qian Cai <cai@lca.pw> Acked-by:
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Roman Gushchin authored
Currently the memcg_params.dying flag and the corresponding workqueue used for the asynchronous deactivation of kmem_caches is synchronized using the slab_mutex. It makes impossible to check this flag from the irq context, which will be required in order to implement asynchronous release of kmem_caches. So let's switch over to the irq-save flavor of the spinlock-based synchronization. Link: http://lkml.kernel.org/r/20190611231813.3148843-8-guro@fb.comSigned-off-by:
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Roman Gushchin authored
There is no point in checking the root_cache->memcg_params.dying flag on kmem_cache creation path. New allocations shouldn't be performed using a dead root kmem_cache, so no new memcg kmem_cache creation can be scheduled after the flag is set. And if it was scheduled before, flush_memcg_workqueue() will wait for it anyway. So let's drop this check to simplify the code. Link: http://lkml.kernel.org/r/20190611231813.3148843-7-guro@fb.comSigned-off-by:
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Roman Gushchin authored
Currently the page accounting code is duplicated in SLAB and SLUB internals. Let's move it into new (un)charge_slab_page helpers in the slab_common.c file. These helpers will be responsible for statistics (global and memcg-aware) and memcg charging. So they are replacing direct memcg_(un)charge_slab() calls. Link: http://lkml.kernel.org/r/20190611231813.3148843-6-guro@fb.comSigned-off-by:
Christoph Lameter <cl@linux.com> Acked-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Waiman Long <longman@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Qian Cai <cai@lca.pw> Signed-off-by:
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Roman Gushchin authored
Let's separate the page counter modification code out of __memcg_kmem_uncharge() in a way similar to what __memcg_kmem_charge() and __memcg_kmem_charge_memcg() work. This will allow to reuse this code later using a new memcg_kmem_uncharge_memcg() wrapper, which calls __memcg_kmem_uncharge_memcg() if memcg_kmem_enabled() check is passed. Link: http://lkml.kernel.org/r/20190611231813.3148843-5-guro@fb.comSigned-off-by:
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Roman Gushchin authored
Currently SLUB uses a work scheduled after an RCU grace period to deactivate a non-root kmem_cache. This mechanism can be reused for kmem_caches release, but requires generalization for SLAB case. Introduce kmemcg_cache_deactivate() function, which calls allocator-specific __kmem_cache_deactivate() and schedules execution of __kmem_cache_deactivate_after_rcu() with all necessary locks in a worker context after an rcu grace period. Here is the new calling scheme: kmemcg_cache_deactivate() __kmemcg_cache_deactivate() SLAB/SLUB-specific kmemcg_rcufn() rcu kmemcg_workfn() work __kmemcg_cache_deactivate_after_rcu() SLAB/SLUB-specific instead of: __kmemcg_cache_deactivate() SLAB/SLUB-specific slab_deactivate_memcg_cache_rcu_sched() SLUB-only kmemcg_rcufn() rcu kmemcg_workfn() work kmemcg_cache_deact_after_rcu() SLUB-only For consistency, all allocator-specific functions start with "__". Link: http://lkml.kernel.org/r/20190611231813.3148843-4-guro@fb.comSigned-off-by: -
Roman Gushchin authored
The delayed work/rcu deactivation infrastructure of non-root kmem_caches can be also used for asynchronous release of these objects. Let's get rid of the word "deactivation" in corresponding names to make the code look better after generalization. It's easier to make the renaming first, so that the generalized code will look consistent from scratch. Let's rename struct memcg_cache_params fields: deact_fn -> work_fn deact_rcu_head -> rcu_head deact_work -> work And RCU/delayed work callbacks in slab common code: kmemcg_deactivate_rcufn -> kmemcg_rcufn kmemcg_deactivate_workfn -> kmemcg_workfn This patch contains no functional changes, only renamings. Link: http://lkml.kernel.org/r/20190611231813.3148843-3-guro@fb.comSigned-off-by:
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