- 14 May, 2019 40 commits
-
-
Linxu Fang authored
342332e6 ("mm/page_alloc.c: introduce kernelcore=mirror option") and later patches rewrote the calculation of node spanned pages. e506b996 ("mem-hotplug: fix node spanned pages when we have a movable node"), but the current code still has problems, When we have a node with only zone_movable and the node id is not zero, the size of node spanned pages is double added. That's because we have an empty normal zone, and zone_start_pfn or zone_end_pfn is not between arch_zone_lowest_possible_pfn and arch_zone_highest_possible_pfn, so we need to use clamp to constrain the range just like the commit <96e907d1> (bootmem: Reimplement __absent_pages_in_range() using for_each_mem_pfn_range()). e.g. Zone ranges: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x000000023fffffff] Movable zone start for each node Node 0: 0x0000000100000000 Node 1: 0x0000000140000000 Early memory node ranges node 0: [mem 0x0000000000001000-0x000000000009efff] node 0: [mem 0x0000000000100000-0x00000000bffdffff] node 0: [mem 0x0000000100000000-0x000000013fffffff] node 1: [mem 0x0000000140000000-0x000000023fffffff] node 0 DMA spanned:0xfff present:0xf9e absent:0x61 node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020 node 0 Normal spanned:0 present:0 absent:0 node 0 Movable spanned:0x40000 present:0x40000 absent:0 On node 0 totalpages(node_present_pages): 1048446 node_spanned_pages:1310719 node 1 DMA spanned:0 present:0 absent:0 node 1 DMA32 spanned:0 present:0 absent:0 node 1 Normal spanned:0x100000 present:0x100000 absent:0 node 1 Movable spanned:0x100000 present:0x100000 absent:0 On node 1 totalpages(node_present_pages): 2097152 node_spanned_pages:2097152 Memory: 6967796K/12582392K available (16388K kernel code, 3686K rwdata, 4468K rodata, 2160K init, 10444K bss, 5614596K reserved, 0K cma-reserved) It shows that the current memory of node 1 is double added. After this patch, the problem is fixed. node 0 DMA spanned:0xfff present:0xf9e absent:0x61 node 0 DMA32 spanned:0xff000 present:0xbefe0 absent:0x40020 node 0 Normal spanned:0 present:0 absent:0 node 0 Movable spanned:0x40000 present:0x40000 absent:0 On node 0 totalpages(node_present_pages): 1048446 node_spanned_pages:1310719 node 1 DMA spanned:0 present:0 absent:0 node 1 DMA32 spanned:0 present:0 absent:0 node 1 Normal spanned:0 present:0 absent:0 node 1 Movable spanned:0x100000 present:0x100000 absent:0 On node 1 totalpages(node_present_pages): 1048576 node_spanned_pages:1048576 memory: 6967796K/8388088K available (16388K kernel code, 3686K rwdata, 4468K rodata, 2160K init, 10444K bss, 1420292K reserved, 0K cma-reserved) Link: http://lkml.kernel.org/r/1554178276-10372-1-git-send-email-fanglinxu@huawei.comSigned-off-by:
Linxu Fang <fanglinxu@huawei.com> Cc: Taku Izumi <izumi.taku@jp.fujitsu.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
-
Yafang Shao authored
There are three tracepoints using this template, which are mm_vmscan_direct_reclaim_begin, mm_vmscan_memcg_reclaim_begin, mm_vmscan_memcg_softlimit_reclaim_begin. Regarding mm_vmscan_direct_reclaim_begin, sc.may_writepage is !laptop_mode, that's a static setting, and reclaim_idx is derived from gfp_mask which is already show in this tracepoint. Regarding mm_vmscan_memcg_reclaim_begin, may_writepage is !laptop_mode too, and reclaim_idx is (MAX_NR_ZONES-1), which are both static value. mm_vmscan_memcg_softlimit_reclaim_begin is the same with mm_vmscan_memcg_reclaim_begin. So we can drop them all. Link: http://lkml.kernel.org/r/1553736322-32235-1-git-send-email-laoar.shao@gmail.comSigned-off-by:
Yafang Shao <laoar.shao@gmail.com> Acked-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
-
Aneesh Kumar K.V authored
MADV_DONTNEED is handled with mmap_sem taken in read mode. We call page_mkclean without holding mmap_sem. MADV_DONTNEED implies that pages in the region are unmapped and subsequent access to the pages in that range is handled as a new page fault. This implies that if we don't have parallel access to the region when MADV_DONTNEED is run we expect those range to be unallocated. w.r.t page_mkclean() we need to make sure that we don't break the MADV_DONTNEED semantics. MADV_DONTNEED check for pmd_none without holding pmd_lock. This implies we skip the pmd if we temporarily mark pmd none. Avoid doing that while marking the page clean. Keep the sequence same for dax too even though we don't support MADV_DONTNEED for dax mapping The bug was noticed by code review and I didn't observe any failures w.r.t test run. This is similar to commit 58ceeb6b Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Date: Thu Apr 13 14:56:26 2017 -0700 thp: fix MADV_DONTNEED vs. MADV_FREE race commit ced10803 Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Date: Thu Apr 13 14:56:20 2017 -0700 thp: fix MADV_DONTNEED vs. numa balancing race Link: http://lkml.kernel.org/r/20190321040610.14226-1-aneesh.kumar@linux.ibm.comSigned-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by:
-
John Hubbard authored
A discussion of the overall problem is below. As mentioned in patch 0001, the steps are to fix the problem are: 1) Provide put_user_page*() routines, intended to be used for releasing pages that were pinned via get_user_pages*(). 2) Convert all of the call sites for get_user_pages*(), to invoke put_user_page*(), instead of put_page(). This involves dozens of call sites, and will take some time. 3) After (2) is complete, use get_user_pages*() and put_user_page*() to implement tracking of these pages. This tracking will be separate from the existing struct page refcounting. 4) Use the tracking and identification of these pages, to implement special handling (especially in writeback paths) when the pages are backed by a filesystem. Overview ======== Some kernel components (file systems, device drivers) need to access memory that is specified via process virtual address. For a long time, the API to achieve that was get_user_pages ("GUP") and its variations. However, GUP has critical limitations that have been overlooked; in particular, GUP does not interact correctly with filesystems in all situations. That means that file-backed memory + GUP is a recipe for potential problems, some of which have already occurred in the field. GUP was first introduced for Direct IO (O_DIRECT), allowing filesystem code to get the struct page behind a virtual address and to let storage hardware perform a direct copy to or from that page. This is a short-lived access pattern, and as such, the window for a concurrent writeback of GUP'd page was small enough that there were not (we think) any reported problems. Also, userspace was expected to understand and accept that Direct IO was not synchronized with memory-mapped access to that data, nor with any process address space changes such as munmap(), mremap(), etc. Over the years, more GUP uses have appeared (virtualization, device drivers, RDMA) that can keep the pages they get via GUP for a long period of time (seconds, minutes, hours, days, ...). This long-term pinning makes an underlying design problem more obvious. In fact, there are a number of key problems inherent to GUP: Interactions with file systems ============================== File systems expect to be able to write back data, both to reclaim pages, and for data integrity. Allowing other hardware (NICs, GPUs, etc) to gain write access to the file memory pages means that such hardware can dirty the pages, without the filesystem being aware. This can, in some cases (depending on filesystem, filesystem options, block device, block device options, and other variables), lead to data corruption, and also to kernel bugs of the form: kernel BUG at /build/linux-fQ94TU/linux-4.4.0/fs/ext4/inode.c:1899! backtrace: ext4_writepage __writepage write_cache_pages ext4_writepages do_writepages __writeback_single_inode writeback_sb_inodes __writeback_inodes_wb wb_writeback wb_workfn process_one_work worker_thread kthread ret_from_fork ...which is due to the file system asserting that there are still buffer heads attached: ({ \ BUG_ON(!PagePrivate(page)); \ ((struct buffer_head *)page_private(page)); \ }) Dave Chinner's description of this is very clear: "The fundamental issue is that ->page_mkwrite must be called on every write access to a clean file backed page, not just the first one. How long the GUP reference lasts is irrelevant, if the page is clean and you need to dirty it, you must call ->page_mkwrite before it is marked writeable and dirtied. Every. Time." This is just one symptom of the larger design problem: real filesystems that actually write to a backing device, do not actually support get_user_pages() being called on their pages, and letting hardware write directly to those pages--even though that pattern has been going on since about 2005 or so. Long term GUP ============= Long term GUP is an issue when FOLL_WRITE is specified to GUP (so, a writeable mapping is created), and the pages are file-backed. That can lead to filesystem corruption. What happens is that when a file-backed page is being written back, it is first mapped read-only in all of the CPU page tables; the file system then assumes that nobody can write to the page, and that the page content is therefore stable. Unfortunately, the GUP callers generally do not monitor changes to the CPU pages tables; they instead assume that the following pattern is safe (it's not): get_user_pages() Hardware can keep a reference to those pages for a very long time, and write to it at any time. Because "hardware" here means "devices that are not a CPU", this activity occurs without any interaction with the kernel's file system code. for each page set_page_dirty put_page() In fact, the GUP documentation even recommends that pattern. Anyway, the file system assumes that the page is stable (nothing is writing to the page), and that is a problem: stable page content is necessary for many filesystem actions during writeback, such as checksum, encryption, RAID striping, etc. Furthermore, filesystem features like COW (copy on write) or snapshot also rely on being able to use a new page for as memory for that memory range inside the file. Corruption during write back is clearly possible here. To solve that, one idea is to identify pages that have active GUP, so that we can use a bounce page to write stable data to the filesystem. The filesystem would work on the bounce page, while any of the active GUP might write to the original page. This would avoid the stable page violation problem, but note that it is only part of the overall solution, because other problems remain. Other filesystem features that need to replace the page with a new one can be inhibited for pages that are GUP-pinned. This will, however, alter and limit some of those filesystem features. The only fix for that would be to require GUP users to monitor and respond to CPU page table updates. Subsystems such as ODP and HMM do this, for example. This aspect of the problem is still under discussion. Direct IO ========= Direct IO can cause corruption, if userspace does Direct-IO that writes to a range of virtual addresses that are mmap'd to a file. The pages written to are file-backed pages that can be under write back, while the Direct IO is taking place. Here, Direct IO races with a write back: it calls GUP before page_mkclean() has replaced the CPU pte with a read-only entry. The race window is pretty small, which is probably why years have gone by before we noticed this problem: Direct IO is generally very quick, and tends to finish up before the filesystem gets around to do anything with the page contents. However, it's still a real problem. The solution is to never let GUP return pages that are under write back, but instead, force GUP to take a write fault on those pages. That way, GUP will properly synchronize with the active write back. This does not change the required GUP behavior, it just avoids that race. Details ======= Introduces put_user_page(), which simply calls put_page(). This provides a way to update all get_user_pages*() callers, so that they call put_user_page(), instead of put_page(). Also introduces put_user_pages(), and a few dirty/locked variations, as a replacement for release_pages(), and also as a replacement for open-coded loops that release multiple pages. These may be used for subsequent performance improvements, via batching of pages to be released. This is the first step of fixing a problem (also described in [1] and [2]) with interactions between get_user_pages ("gup") and filesystems. Problem description: let's start with a bug report. Below, is what happens sometimes, under memory pressure, when a driver pins some pages via gup, and then marks those pages dirty, and releases them. Note that the gup documentation actually recommends that pattern. The problem is that the filesystem may do a writeback while the pages were gup-pinned, and then the filesystem believes that the pages are clean. So, when the driver later marks the pages as dirty, that conflicts with the filesystem's page tracking and results in a BUG(), like this one that I experienced: kernel BUG at /build/linux-fQ94TU/linux-4.4.0/fs/ext4/inode.c:1899! backtrace: ext4_writepage __writepage write_cache_pages ext4_writepages do_writepages __writeback_single_inode writeback_sb_inodes __writeback_inodes_wb wb_writeback wb_workfn process_one_work worker_thread kthread ret_from_fork ...which is due to the file system asserting that there are still buffer heads attached: ({ \ BUG_ON(!PagePrivate(page)); \ ((struct buffer_head *)page_private(page)); \ }) Dave Chinner's description of this is very clear: "The fundamental issue is that ->page_mkwrite must be called on every write access to a clean file backed page, not just the first one. How long the GUP reference lasts is irrelevant, if the page is clean and you need to dirty it, you must call ->page_mkwrite before it is marked writeable and dirtied. Every. Time." This is just one symptom of the larger design problem: real filesystems that actually write to a backing device, do not actually support get_user_pages() being called on their pages, and letting hardware write directly to those pages--even though that pattern has been going on since about 2005 or so. The steps are to fix it are: 1) (This patch): provide put_user_page*() routines, intended to be used for releasing pages that were pinned via get_user_pages*(). 2) Convert all of the call sites for get_user_pages*(), to invoke put_user_page*(), instead of put_page(). This involves dozens of call sites, and will take some time. 3) After (2) is complete, use get_user_pages*() and put_user_page*() to implement tracking of these pages. This tracking will be separate from the existing struct page refcounting. 4) Use the tracking and identification of these pages, to implement special handling (especially in writeback paths) when the pages are backed by a filesystem. [1] https://lwn.net/Articles/774411/ : "DMA and get_user_pages()" [2] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()" Link: http://lkml.kernel.org/r/20190327023632.13307-2-jhubbard@nvidia.comSigned-off-by:John Hubbard <jhubbard@nvidia.com> Reviewed-by:
Jan Kara <jack@suse.cz> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> [docs] Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Reviewed-by:
Jérôme Glisse <jglisse@redhat.com> Reviewed-by:
Christoph Lameter <cl@linux.com> Tested-by:
-
Alexandre Ghiti authored
On systems without CONTIG_ALLOC activated but that support gigantic pages, boottime reserved gigantic pages can not be freed at all. This patch simply enables the possibility to hand back those pages to memory allocator. Link: http://lkml.kernel.org/r/20190327063626.18421-5-alex@ghiti.frSigned-off-by:
Alexandre Ghiti <alex@ghiti.fr> Acked-by: David S. Miller <davem@davemloft.net> [sparc] Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
-
Alexandre Ghiti authored
This condition allows to define alloc_contig_range, so simplify it into a more accurate naming. Link: http://lkml.kernel.org/r/20190327063626.18421-4-alex@ghiti.frSigned-off-by:
Vlastimil Babka <vbabka@suse.cz> Acked-by:
-
Alexandre Ghiti authored
sparc actually supports gigantic pages and selecting ARCH_HAS_GIGANTIC_PAGE allows it to allocate and free gigantic pages at runtime. sparc allows configuration such as huge pages of 16GB, pages of 8KB and MAX_ORDER = 13 (default): HPAGE_SHIFT (34) - PAGE_SHIFT (13) = 21 >= MAX_ORDER (13) Link: http://lkml.kernel.org/r/20190327063626.18421-3-alex@ghiti.frSigned-off-by:
David S. Miller <davem@davemloft.net> Cc: Andy Lutomirsky <luto@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
-
Alexandre Ghiti authored
Patch series "Fix free/allocation of runtime gigantic pages", v8. This series fixes sh and sparc that did not advertise their gigantic page support and then were not able to allocate and free those pages at runtime. It renames MEMORY_ISOLATION && COMPACTION || CMA condition into the more accurate CONTIG_ALLOC, since it allows the definition of alloc_contig_range function. Finally, it then fixes the wrong definition of ARCH_HAS_GIGANTIC_PAGE config that, without MEMORY_ISOLATION && COMPACTION || CMA defined, did not allow architectures to free boottime allocated gigantic pages although unrelated. This patch (of 4): sh actually supports gigantic pages and selecting ARCH_HAS_GIGANTIC_PAGE allows it to allocate and free gigantic pages at runtime. At least sdk7786_defconfig exposes such a configuration with huge pages of 64MB, pages of 4KB and MAX_ORDER = 11: HPAGE_SHIFT (26) - PAGE_SHIFT (12) = 14 >= MAX_ORDER (11) Link: http://lkml.kernel.org/r/20190327063626.18421-2-alex@ghiti.frSigned-off-by:
-
Mike Rapoport authored
The riscv version of free_initmem() differs from the generic one only in that it sets the freed memory to zero. Make ricsv use the generic version and poison the freed memory. Link: http://lkml.kernel.org/r/1550515285-17446-5-git-send-email-rppt@linux.ibm.comSigned-off-by:
Mike Rapoport <rppt@linux.ibm.com> Reviewed-by:
Palmer Dabbelt <palmer@sifive.com> Reviewed-by:
-
Mike Rapoport authored
Various architectures including x86 poison the freed init memory. Do the same in the generic free_initmem implementation and switch sparc32 architecture that is identical to the generic code over to it now. Link: http://lkml.kernel.org/r/1550515285-17446-4-git-send-email-rppt@linux.ibm.comSigned-off-by:
-
Mike Rapoport authored
hexagon implementation of free_initmem() is currently empty and marked with comment * Todo: free pages between __init_begin and __init_end; possibly * some devtree related stuff as well. Switch it to the generic implementation. Link: http://lkml.kernel.org/r/1550515285-17446-3-git-send-email-rppt@linux.ibm.comSigned-off-by:
-
Mike Rapoport authored
Patch series "provide a generic free_initmem implementation", v2. Many architectures implement free_initmem() in exactly the same or very similar way: they wrap the call to free_initmem_default() with sometimes different 'poison' parameter. These patches switch those architectures to use a generic implementation that does free_initmem_default(POISON_FREE_INITMEM). This was inspired by Christoph's patches for free_initrd_mem [1] and I shamelessly copied changelog entries from his patches :) [1] https://lore.kernel.org/lkml/20190213174621.29297-1-hch@lst.de/ This patch (of 2): For most architectures free_initmem just a wrapper for the same free_initmem_default(-1) call. Provide that as a generic implementation marked __weak. Link: http://lkml.kernel.org/r/1550515285-17446-2-git-send-email-rppt@linux.ibm.comSigned-off-by:
-
Christoph Hellwig authored
Various architectures including x86 poison the freed initrd memory. Do the same in the generic free_initrd_mem implementation and switch a few more architectures that are identical to the generic code over to it now. Link: http://lkml.kernel.org/r/20190213174621.29297-9-hch@lst.deSigned-off-by:
Christoph Hellwig <hch@lst.de> Acked-by:
-
Christoph Hellwig authored
For most architectures free_initrd_mem just expands to the same free_reserved_area call. Provide that as a generic implementation marked __weak. Link: http://lkml.kernel.org/r/20190213174621.29297-8-hch@lst.deSigned-off-by:
-
Christoph Hellwig authored
No need to handle the freeing disable in arch code when we already have a core hook (and a different name for the option) for it. Link: http://lkml.kernel.org/r/20190213174621.29297-7-hch@lst.deSigned-off-by:
-
Christoph Hellwig authored
The code for kernels that support ramdisks or not is mostly the same. Unify it by using an IS_ENABLED for the info message, and moving the error message into a stub for populate_initrd_image. [cai@lca.pw: fix a compilation error] Link: http://lkml.kernel.org/r/20190328014806.36375-1-cai@lca.pw Link: http://lkml.kernel.org/r/20190213174621.29297-6-hch@lst.deSigned-off-by:
Qian Cai <cai@lca.pw> Acked-by:
-
Christoph Hellwig authored
This will allow for cleaner code sharing in the caller. Link: http://lkml.kernel.org/r/20190213174621.29297-5-hch@lst.deSigned-off-by:
-
Christoph Hellwig authored
Factor the kexec logic into a separate helper, and then inline the rest of free_initrd into the only caller. Link: http://lkml.kernel.org/r/20190213174621.29297-4-hch@lst.deSigned-off-by:
-
Christoph Hellwig authored
Patch series "initramfs tidyups". I've spent some time chasing down behavior in initramfs and found plenty of opportunity to improve the code. A first stab on that is contained in this series. This patch (of 7): We free the initrd memory for all successful or error cases except for the case where opening /initrd.image fails, which looks like an oversight. Steven said: : This also changes the behaviour when CONFIG_INITRAMFS_FORCE is enabled : - specifically it means that the initrd is freed (previously it was : ignored and never freed). But that seems like reasonable behaviour and : the previous behaviour looks like another oversight. Link: http://lkml.kernel.org/r/20190213174621.29297-3-hch@lst.deSigned-off-by:
Steven Price <steven.price@arm.com> Acked-by:
-
Yue Hu authored
f022d8cb ("mm: cma: Don't crash on allocation if CMA area can't be activated") fixes the crash issue when activation fails via setting cma->count as 0, same logic exists if bitmap allocation fails. Link: http://lkml.kernel.org/r/20190325081309.6004-1-zbestahu@gmail.comSigned-off-by:
Yue Hu <huyue2@yulong.com> Reviewed-by:
Anshuman Khandual <anshuman.khandual@arm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
-
Johannes Weiner authored
Only memcg_numa_stat_show() uses those wrappers and the lru bitmasks, group them together. Link: http://lkml.kernel.org/r/20190228163020.24100-7-hannes@cmpxchg.orgSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
-
Johannes Weiner authored
mem_cgroup_nr_lru_pages() is just a convenience wrapper around memcg_page_state() that takes bitmasks of lru indexes and aggregates the counts for those. Replace callsites where the bitmask is simple enough with direct memcg_page_state() call(s). Link: http://lkml.kernel.org/r/20190228163020.24100-6-hannes@cmpxchg.orgSigned-off-by:
-
Johannes Weiner authored
mem_cgroup_node_nr_lru_pages() is just a convenience wrapper around lruvec_page_state() that takes bitmasks of lru indexes and aggregates the counts for those. Replace callsites where the bitmask is simple enough with direct lruvec_page_state() calls. This removes the last extern user of mem_cgroup_node_nr_lru_pages(), so make that function private again, too. Link: http://lkml.kernel.org/r/20190228163020.24100-5-hannes@cmpxchg.orgSigned-off-by:
-
Johannes Weiner authored
Instead of adding up the node counters, use memcg_page_state() to get the memcg state directly. This is a bit cheaper and more stream-lined. Link: http://lkml.kernel.org/r/20190228163020.24100-4-hannes@cmpxchg.orgSigned-off-by:
-
Johannes Weiner authored
Instead of adding up the zone counters, use lruvec_page_state() to get the node state directly. This is a bit cheaper and more stream-lined. Link: http://lkml.kernel.org/r/20190228163020.24100-3-hannes@cmpxchg.orgSigned-off-by:
-
Johannes Weiner authored
Patch series "mm: memcontrol: clean up the LRU counts tracking". The memcg LRU stats usage is currently a bit messy. Memcg has private per-zone counters because reclaim needs zone granularity sometimes, but we also have plenty of users that need to awkwardly sum them up to node or memcg granularity. Meanwhile the canonical per-memcg vmstats do not track the LRU counts (NR_INACTIVE_ANON etc.) as you'd expect. This series enables LRU count tracking in the per-memcg vmstats array such that lruvec_page_state() and memcg_page_state() work on the enum node_stat_item items for the LRU counters. Then it converts all the callers that don't specifically need per-zone numbers over to that. This patch (of 6): The memcg code currently maintains private per-zone breakdowns of the LRU counters. This is necessary for reclaim decisions which are still zone-based, but there are a variety of users of these counters that only want the aggregate per-lruvec or per-memcg LRU counts, and they need to painfully sum up the zone counters on each request for that. These would be better served using the memcg vmstats arrays, which track VM statistics at the desired scope already. They just don't have the LRU counts right now. So to kick off the conversion, begin tracking LRU counts in those. Link: http://lkml.kernel.org/r/20190228163020.24100-2-hannes@cmpxchg.orgSigned-off-by:
-
Yafang Shao authored
The page alloc fast path it may perform node reclaim, which may cause a latency spike. We should add tracepoint for this event, and also measure the latency it causes. So bellow two tracepoints are introduced, mm_vmscan_node_reclaim_begin mm_vmscan_node_reclaim_end Link: http://lkml.kernel.org/r/1551421452-5385-1-git-send-email-laoar.shao@gmail.comSigned-off-by:
-
Anshuman Khandual authored
pfn_valid_within() calls pfn_valid() when CONFIG_HOLES_IN_ZONE making it redundant for both definitions (w/wo CONFIG_MEMORY_HOTPLUG) of the helper pfn_to_online_page() which either calls pfn_valid() or pfn_valid_within(). pfn_valid_within() being 1 when !CONFIG_HOLES_IN_ZONE is irrelevant either way. This does not change functionality. Link: http://lkml.kernel.org/r/1553141595-26907-1-git-send-email-anshuman.khandual@arm.comSigned-off-by:
Zi Yan <ziy@nvidia.com> Reviewed-by:
Oscar Salvador <osalvador@suse.de> Acked-by:
-
Yafang Shao authored
Only mm_compaction_isolate_{free, migrate}pages may be used when CONFIG_COMPACTION is not set. All others are used only when CONFIG_COMPACTION is set. After this change, if CONFIG_COMPACTION is not set, the tracepoints that only work when CONFIG_COMPACTION is set will not be exposed to userspace. Without this change, they will always be exposed in debugfs whether CONFIG_COMPACTION is set or not. This is an improvement. Link: http://lkml.kernel.org/r/1552440403-11780-1-git-send-email-laoar.shao@gmail.comSigned-off-by: -
Yafang Shao authored
Showing the gfp flag names instead of the gfp_mask makes trace more convenient. Link: http://lkml.kernel.org/r/1552527998-13162-1-git-send-email-laoar.shao@gmail.comSigned-off-by:
-
Yue Hu authored
Currently one bit in cma bitmap represents number of pages rather than one page, cma->count means cma size in pages. So to find available pages via find_next_zero_bit()/find_next_bit() we should use cma size not in pages but in bits although current free pages number is correct due to zero value of order_per_bit. Once order_per_bit is changed the bitmap status will be incorrect. The size input in cma_debug_show_areas() is not correct. It will affect the available pages at some position to debug the failure issue. This is an example with order_per_bit = 1 Before this change: [ 4.120060] cma: number of available pages: 1@93+4@108+7@121+7@137+7@153+7@169+7@185+7@201+3@213+3@221+3@229+3@237+3@245+3@253+3@261+3@269+3@277+3@285+3@293+3@301+3@309+3@317+3@325+19@333+15@369+512@512=> 638 free of 1024 total pages After this change: [ 4.143234] cma: number of available pages: 2@93+8@108+14@121+14@137+14@153+14@169+14@185+14@201+6@213+6@221+6@229+6@237+6@245+6@253+6@261+6@269+6@277+6@285+6@293+6@301+6@309+6@317+6@325+38@333+30@369=> 252 free of 1024 total pages Obviously the bitmap status before is incorrect. Link: http://lkml.kernel.org/r/20190320060829.9144-1-zbestahu@gmail.comSigned-off-by:
-
Qian Cai authored
In a low-memory situation, cc->fast_search_fail can keep increasing as it is unable to find an available page to isolate in fast_isolate_freepages(). As the result, it could trigger an error below, so just compare with the maximum bits can be shifted first. UBSAN: Undefined behaviour in mm/compaction.c:1160:30 shift exponent 64 is too large for 64-bit type 'unsigned long' CPU: 131 PID: 1308 Comm: kcompactd1 Kdump: loaded Tainted: G W L 5.0.0+ #17 Call trace: dump_backtrace+0x0/0x450 show_stack+0x20/0x2c dump_stack+0xc8/0x14c __ubsan_handle_shift_out_of_bounds+0x7e8/0x8c4 compaction_alloc+0x2344/0x2484 unmap_and_move+0xdc/0x1dbc migrate_pages+0x274/0x1310 compact_zone+0x26ec/0x43bc kcompactd+0x15b8/0x1a24 kthread+0x374/0x390 ret_from_fork+0x10/0x18 [akpm@linux-foundation.org: code cleanup] Link: http://lkml.kernel.org/r/20190320203338.53367-1-cai@lca.pw Fixes: 70b44595 ("mm, compaction: use free lists to quickly locate a migration source") Signed-off-by:
Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
-
Baoquan He authored
In node_states_check_changes_online(), N_HIGH_MEMORY is used to substitute ZONE_HIGHMEM directly. This is not right. N_HIGH_MEMORY is to mark the memory state of node. Here zone index is checked, which should be compared with 'ZONE_HIGHMEM' accordingly. Replace it with ZONE_HIGHMEM. This is a code cleanup - no known runtime effects. Link: http://lkml.kernel.org/r/20190320080732.14933-1-bhe@redhat.com Fixes: 8efe33f4 ("mm/memory_hotplug.c: simplify node_states_check_changes_online") Signed-off-by:
Baoquan He <bhe@redhat.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Acked-by:
-
Oscar Salvador authored
has_unmovable_pages() already checks whether the hugetlb page supports migration, so all non-migratable hugetlb pages should have been caught there. Let us drop the check from scan_movable_pages() as is redundant. Link: http://lkml.kernel.org/r/20190320152658.10855-3-osalvador@suse.deSigned-off-by:
-
Oscar Salvador authored
On x86_64, 1GB-hugetlb pages could never be offlined due to the fact that hugepage_migration_supported() returned false for PUD_SHIFT. So whenever we wanted to offline a memblock containing a gigantic hugetlb page, we never got beyond has_unmovable_pages() check. This changed with [1], where now we also return true for PUD_SHIFT. After that patch, the check in has_unmovable_pages() and scan_movable_pages() returned true, but we still had a final barrier in do_migrate_range(): if (compound_order(head) > PFN_SECTION_SHIFT) { ret = -EBUSY; break; } This is not really nice, and we do not really need it. It is perfectly possible to migrate a gigantic page as long as another node has a spare gigantic page for us. In alloc_huge_page_nodemask(), we calculate the __real__ number of free pages, and if any, we try to dequeue one from another node. This all works fine when we do have another node with a spare gigantic page, but if that is not the case, alloc_huge_page_nodemask() ends up calling alloc_migrate_huge_page() which bails out if the wanted page is gigantic. That is mainly because finding a 1GB (or even 16GB on powerpc) contiguous memory is quite unlikely when the system has been running for a while. In that situation, we will keep looping forever because scan_movable_pages() will give us the same page and we will fail again because there is no node where we can dequeue a gigantic page from. This is not nice, and it has been raised that we might want to treat -ENOMEM as a fatal error in do_migrate_range(), but this has to be checked further. Anyway, I would tend say that this is the administrator's job, to make sure that the system can keep up with the memory to be offlined, so that would mean that if we want to use gigantic pages, make sure that the other nodes have at least enough gigantic pages to keep up in case we need to offline memory. Just for the sake of completeness, this is one of the tests done: # echo 1 > /sys/devices/system/node/node1/hugepages/hugepages-1048576kB/nr_hugepages # echo 1 > /sys/devices/system/node/node2/hugepages/hugepages-1048576kB/nr_hugepages # cat /sys/devices/system/node/node1/hugepages/hugepages-1048576kB/nr_hugepages 1 # cat /sys/devices/system/node/node1/hugepages/hugepages-1048576kB/free_hugepages 1 # cat /sys/devices/system/node/node2/hugepages/hugepages-1048576kB/nr_hugepages 1 # cat /sys/devices/system/node/node2/hugepages/hugepages-1048576kB/free_hugepages 1 (hugetlb1gb is a program that maps 1GB region using MAP_HUGE_1GB) # numactl -m 1 ./hugetlb1gb # cat /sys/devices/system/node/node1/hugepages/hugepages-1048576kB/free_hugepages 0 # cat /sys/devices/system/node/node2/hugepages/hugepages-1048576kB/free_hugepages 1 # offline node1 memory # cat /sys/devices/system/node/node2/hugepages/hugepages-1048576kB/free_hugepages 0 [1] https://lore.kernel.org/patchwork/patch/998796/ Link: http://lkml.kernel.org/r/20190320152658.10855-2-osalvador@suse.deSigned-off-by: -
Ira Weiny authored
Use the new FOLL_LONGTERM to get_user_pages_fast() to protect against FS DAX pages being mapped. Link: http://lkml.kernel.org/r/20190328084422.29911-8-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-8-ira.weiny@intel.comSigned-off-by:
-
Ira Weiny authored
Use the new FOLL_LONGTERM to get_user_pages_fast() to protect against FS DAX pages being mapped. Link: http://lkml.kernel.org/r/20190328084422.29911-7-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-7-ira.weiny@intel.comSigned-off-by:
Dan Williams <dan.j.williams@intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Mike Marshall <hubcap@omnibond.com> Signed-off-by:
-
Ira Weiny authored
Use the new FOLL_LONGTERM to get_user_pages_fast() to protect against FS DAX pages being mapped. [ira.weiny@intel.com: v3] Link: http://lkml.kernel.org/r/20190328084422.29911-6-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190328084422.29911-6-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-6-ira.weiny@intel.comSigned-off-by:
-
Ira Weiny authored
DAX pages were previously unprotected from longterm pins when users called get_user_pages_fast(). Use the new FOLL_LONGTERM flag to check for DEVMAP pages and fall back to regular GUP processing if a DEVMAP page is encountered. [ira.weiny@intel.com: v3] Link: http://lkml.kernel.org/r/20190328084422.29911-5-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190328084422.29911-5-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-5-ira.weiny@intel.comSigned-off-by:
-
Ira Weiny authored
To facilitate additional options to get_user_pages_fast() change the singular write parameter to be gup_flags. This patch does not change any functionality. New functionality will follow in subsequent patches. Some of the get_user_pages_fast() call sites were unchanged because they already passed FOLL_WRITE or 0 for the write parameter. NOTE: It was suggested to change the ordering of the get_user_pages_fast() arguments to ensure that callers were converted. This breaks the current GUP call site convention of having the returned pages be the final parameter. So the suggestion was rejected. Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.comSigned-off-by:
Mike Marshall <hubcap@omnibond.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
-
