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2020-11-18page_frag: Recover from memory pressureDongli Zhang1-0/+5
The ethernet driver may allocate skb (and skb->data) via napi_alloc_skb(). This ends up to page_frag_alloc() to allocate skb->data from page_frag_cache->va. During the memory pressure, page_frag_cache->va may be allocated as pfmemalloc page. As a result, the skb->pfmemalloc is always true as skb->data is from page_frag_cache->va. The skb will be dropped if the sock (receiver) does not have SOCK_MEMALLOC. This is expected behaviour under memory pressure. However, once kernel is not under memory pressure any longer (suppose large amount of memory pages are just reclaimed), the page_frag_alloc() may still re-use the prior pfmemalloc page_frag_cache->va to allocate skb->data. As a result, the skb->pfmemalloc is always true unless page_frag_cache->va is re-allocated, even if the kernel is not under memory pressure any longer. Here is how kernel runs into issue. 1. The kernel is under memory pressure and allocation of PAGE_FRAG_CACHE_MAX_ORDER in __page_frag_cache_refill() will fail. Instead, the pfmemalloc page is allocated for page_frag_cache->va. 2: All skb->data from page_frag_cache->va (pfmemalloc) will have skb->pfmemalloc=true. The skb will always be dropped by sock without SOCK_MEMALLOC. This is an expected behaviour. 3. Suppose a large amount of pages are reclaimed and kernel is not under memory pressure any longer. We expect skb->pfmemalloc drop will not happen. 4. Unfortunately, page_frag_alloc() does not proactively re-allocate page_frag_alloc->va and will always re-use the prior pfmemalloc page. The skb->pfmemalloc is always true even kernel is not under memory pressure any longer. Fix this by freeing and re-allocating the page instead of recycling it. References: https://lore.kernel.org/lkml/20201103193239.1807-1-dongli.zhang@oracle.com/ References: https://lore.kernel.org/linux-mm/20201105042140.5253-1-willy@infradead.org/ Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Bert Barbe <bert.barbe@oracle.com> Cc: Rama Nichanamatlu <rama.nichanamatlu@oracle.com> Cc: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com> Cc: Manjunath Patil <manjunath.b.patil@oracle.com> Cc: Joe Jin <joe.jin@oracle.com> Cc: SRINIVAS <srinivas.eeda@oracle.com> Fixes: 79930f5892e1 ("net: do not deplete pfmemalloc reserve") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20201115201029.11903-1-dongli.zhang@oracle.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-16Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-84/+157
Merge more updates from Andrew Morton: "155 patches. Subsystems affected by this patch series: mm (dax, debug, thp, readahead, page-poison, util, memory-hotplug, zram, cleanups), misc, core-kernel, get_maintainer, MAINTAINERS, lib, bitops, checkpatch, binfmt, ramfs, autofs, nilfs, rapidio, panic, relay, kgdb, ubsan, romfs, and fault-injection" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits) lib, uaccess: add failure injection to usercopy functions lib, include/linux: add usercopy failure capability ROMFS: support inode blocks calculation ubsan: introduce CONFIG_UBSAN_LOCAL_BOUNDS for Clang sched.h: drop in_ubsan field when UBSAN is in trap mode scripts/gdb/tasks: add headers and improve spacing format scripts/gdb/proc: add struct mount & struct super_block addr in lx-mounts command kernel/relay.c: drop unneeded initialization panic: dump registers on panic_on_warn rapidio: fix the missed put_device() for rio_mport_add_riodev rapidio: fix error handling path nilfs2: fix some kernel-doc warnings for nilfs2 autofs: harden ioctl table ramfs: fix nommu mmap with gaps in the page cache mm: remove the now-unnecessary mmget_still_valid() hack mm/gup: take mmap_lock in get_dump_page() binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot coredump: rework elf/elf_fdpic vma_dump_size() into common helper coredump: refactor page range dumping into common helper coredump: let dump_emit() bail out on short writes ...
2020-10-16mm: rename page_order() to buddy_order()Matthew Wilcox (Oracle)1-15/+15
The current page_order() can only be called on pages in the buddy allocator. For compound pages, you have to use compound_order(). This is confusing and led to a bug, so rename page_order() to buddy_order(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20201001152259.14932-2-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_alloc: place pages to tail in __free_pages_core()David Hildenbrand1-10/+23
__free_pages_core() is used when exposing fresh memory to the buddy during system boot and when onlining memory in generic_online_page(). generic_online_page() is used in two cases: 1. Direct memory onlining in online_pages(). 2. Deferred memory onlining in memory-ballooning-like mechanisms (HyperV balloon and virtio-mem), when parts of a section are kept fake-offline to be fake-onlined later on. In 1, we already place pages to the tail of the freelist. Pages will be freed to MIGRATE_ISOLATE lists first and moved to the tail of the freelists via undo_isolate_page_range(). In 2, we currently don't implement a proper rule. In case of virtio-mem, where we currently always online MAX_ORDER - 1 pages, the pages will be placed to the HEAD of the freelist - undesireable. While the hyper-v balloon calls generic_online_page() with single pages, usually it will call it on successive single pages in a larger block. The pages are fresh, so place them to the tail of the freelist and avoid the PCP. In __free_pages_core(), remove the now superflouos call to set_page_refcounted() and add a comment regarding page initialization and the refcount. Note: In 2. we currently don't shuffle. If ever relevant (page shuffling is usually of limited use in virtualized environments), we might want to shuffle after a sequence of generic_online_page() calls in the relevant callers. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@kernel.org> Cc: Scott Cheloha <cheloha@linux.ibm.com> Link: https://lkml.kernel.org/r/20201005121534.15649-5-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_alloc: move pages to tail in move_to_free_list()David Hildenbrand1-3/+7
Whenever we move pages between freelists via move_to_free_list()/ move_freepages_block(), we don't actually touch the pages: 1. Page isolation doesn't actually touch the pages, it simply isolates pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist. When undoing isolation, we move the pages back to the target list. 2. Page stealing (steal_suitable_fallback()) moves free pages directly between lists without touching them. 3. reserve_highatomic_pageblock()/unreserve_highatomic_pageblock() moves free pages directly between freelists without touching them. We already place pages to the tail of the freelists when undoing isolation via __putback_isolated_page(), let's do it in any case (e.g., if order <= pageblock_order) and document the behavior. To simplify, let's move the pages to the tail for all move_to_free_list()/move_freepages_block() users. In 2., the target list is empty, so there should be no change. In 3., we might observe a change, however, highatomic is more concerned about allocations succeeding than cache hotness - if we ever realize this change degrades a workload, we can special-case this instance and add a proper comment. This change results in all pages getting onlined via online_pages() to be placed to the tail of the freelist. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-4-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_alloc: place pages to tail in __putback_isolated_page()David Hildenbrand1-2/+16
__putback_isolated_page() already documents that pages will be placed to the tail of the freelist - this is, however, not the case for "order >= MAX_ORDER - 2" (see buddy_merge_likely()) - which should be the case for all existing users. This change affects two users: - free page reporting - page isolation, when undoing the isolation (including memory onlining). This behavior is desirable for pages that haven't really been touched lately, so exactly the two users that don't actually read/write page content, but rather move untouched pages. The new behavior is especially desirable for memory onlining, where we allow allocation of newly onlined pages via undo_isolate_page_range() in online_pages(). Right now, we always place them to the head of the freelist, resulting in undesireable behavior: Assume we add individual memory chunks via add_memory() and online them right away to the NORMAL zone. We create a dependency chain of unmovable allocations e.g., via the memmap. The memmap of the next chunk will be placed onto previous chunks - if the last block cannot get offlined+removed, all dependent ones cannot get offlined+removed. While this can already be observed with individual DIMMs, it's more of an issue for virtio-mem (and I suspect also ppc DLPAR). Document that this should only be used for optimizations, and no code should rely on this behavior for correction (if the order of the freelists ever changes). We won't care about page shuffling: memory onlining already properly shuffles after onlining. free page reporting doesn't care about physically contiguous ranges, and there are already cases where page isolation will simply move (physically close) free pages to (currently) the head of the freelists via move_freepages_block() instead of shuffling. If this becomes ever relevant, we should shuffle the whole zone when undoing isolation of larger ranges, and after free_contig_range(). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mike Rapoport <rppt@kernel.org> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-3-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_alloc: convert "report" flag of __free_one_page() to a proper flagDavid Hildenbrand1-5/+22
Patch series "mm: place pages to the freelist tail when onlining and undoing isolation", v2. When adding separate memory blocks via add_memory*() and onlining them immediately, the metadata (especially the memmap) of the next block will be placed onto one of the just added+onlined block. This creates a chain of unmovable allocations: If the last memory block cannot get offlined+removed() so will all dependent ones. We directly have unmovable allocations all over the place. This can be observed quite easily using virtio-mem, however, it can also be observed when using DIMMs. The freshly onlined pages will usually be placed to the head of the freelists, meaning they will be allocated next, turning the just-added memory usually immediately un-removable. The fresh pages are cold, prefering to allocate others (that might be hot) also feels to be the natural thing to do. It also applies to the hyper-v balloon xen-balloon, and ppc64 dlpar: when adding separate, successive memory blocks, each memory block will have unmovable allocations on them - for example gigantic pages will fail to allocate. While the ZONE_NORMAL doesn't provide any guarantees that memory can get offlined+removed again (any kind of fragmentation with unmovable allocations is possible), there are many scenarios (hotplugging a lot of memory, running workload, hotunplug some memory/as much as possible) where we can offline+remove quite a lot with this patchset. a) To visualize the problem, a very simple example: Start a VM with 4GB and 8GB of virtio-mem memory: [root@localhost ~]# lsmem RANGE SIZE STATE REMOVABLE BLOCK 0x0000000000000000-0x00000000bfffffff 3G online yes 0-23 0x0000000100000000-0x000000033fffffff 9G online yes 32-103 Memory block size: 128M Total online memory: 12G Total offline memory: 0B Then try to unplug as much as possible using virtio-mem. Observe which memory blocks are still around. Without this patch set: [root@localhost ~]# lsmem RANGE SIZE STATE REMOVABLE BLOCK 0x0000000000000000-0x00000000bfffffff 3G online yes 0-23 0x0000000100000000-0x000000013fffffff 1G online yes 32-39 0x0000000148000000-0x000000014fffffff 128M online yes 41 0x0000000158000000-0x000000015fffffff 128M online yes 43 0x0000000168000000-0x000000016fffffff 128M online yes 45 0x0000000178000000-0x000000017fffffff 128M online yes 47 0x0000000188000000-0x0000000197ffffff 256M online yes 49-50 0x00000001a0000000-0x00000001a7ffffff 128M online yes 52 0x00000001b0000000-0x00000001b7ffffff 128M online yes 54 0x00000001c0000000-0x00000001c7ffffff 128M online yes 56 0x00000001d0000000-0x00000001d7ffffff 128M online yes 58 0x00000001e0000000-0x00000001e7ffffff 128M online yes 60 0x00000001f0000000-0x00000001f7ffffff 128M online yes 62 0x0000000200000000-0x0000000207ffffff 128M online yes 64 0x0000000210000000-0x0000000217ffffff 128M online yes 66 0x0000000220000000-0x0000000227ffffff 128M online yes 68 0x0000000230000000-0x0000000237ffffff 128M online yes 70 0x0000000240000000-0x0000000247ffffff 128M online yes 72 0x0000000250000000-0x0000000257ffffff 128M online yes 74 0x0000000260000000-0x0000000267ffffff 128M online yes 76 0x0000000270000000-0x0000000277ffffff 128M online yes 78 0x0000000280000000-0x0000000287ffffff 128M online yes 80 0x0000000290000000-0x0000000297ffffff 128M online yes 82 0x00000002a0000000-0x00000002a7ffffff 128M online yes 84 0x00000002b0000000-0x00000002b7ffffff 128M online yes 86 0x00000002c0000000-0x00000002c7ffffff 128M online yes 88 0x00000002d0000000-0x00000002d7ffffff 128M online yes 90 0x00000002e0000000-0x00000002e7ffffff 128M online yes 92 0x00000002f0000000-0x00000002f7ffffff 128M online yes 94 0x0000000300000000-0x0000000307ffffff 128M online yes 96 0x0000000310000000-0x0000000317ffffff 128M online yes 98 0x0000000320000000-0x0000000327ffffff 128M online yes 100 0x0000000330000000-0x000000033fffffff 256M online yes 102-103 Memory block size: 128M Total online memory: 8.1G Total offline memory: 0B With this patch set: [root@localhost ~]# lsmem RANGE SIZE STATE REMOVABLE BLOCK 0x0000000000000000-0x00000000bfffffff 3G online yes 0-23 0x0000000100000000-0x000000013fffffff 1G online yes 32-39 Memory block size: 128M Total online memory: 4G Total offline memory: 0B All memory can get unplugged, all memory block can get removed. Of course, no workload ran and the system was basically idle, but it highlights the issue - the fairly deterministic chain of unmovable allocations. When a huge page for the 2MB memmap is needed, a just-onlined 4MB page will be split. The remaining 2MB page will be used for the memmap of the next memory block. So one memory block will hold the memmap of the two following memory blocks. Finally the pages of the last-onlined memory block will get used for the next bigger allocations - if any allocation is unmovable, all dependent memory blocks cannot get unplugged and removed until that allocation is gone. Note that with bigger memory blocks (e.g., 256MB), *all* memory blocks are dependent and none can get unplugged again! b) Experiment with memory intensive workload I performed an experiment with an older version of this patch set (before we used undo_isolate_page_range() in online_pages(): Hotplug 56GB to a VM with an initial 4GB, onlining all memory to ZONE_NORMAL right from the kernel when adding it. I then run various memory intensive workloads that consume most system memory for a total of 45 minutes. Once finished, I try to unplug as much memory as possible. With this change, I am able to remove via virtio-mem (adding individual 128MB memory blocks) 413 out of 448 added memory blocks. Via individual (256MB) DIMMs 380 out of 448 added memory blocks. (I don't have any numbers without this patchset, but looking at the above example, it's at most half of the 448 memory blocks for virtio-mem, and most probably none for DIMMs). Again, there are workloads that might behave very differently due to the nature of ZONE_NORMAL. This change also affects (besides memory onlining): - Other users of undo_isolate_page_range(): Pages are always placed to the tail. -- When memory offlining fails -- When memory isolation fails after having isolated some pageblocks -- When alloc_contig_range() either succeeds or fails - Other users of __putback_isolated_page(): Pages are always placed to the tail. -- Free page reporting - Other users of __free_pages_core() -- AFAIKs, any memory that is getting exposed to the buddy during boot. IIUC we will now usually allocate memory from lower addresses within a zone first (especially during boot). - Other users of generic_online_page() -- Hyper-V balloon This patch (of 5): Let's prepare for additional flags and avoid long parameter lists of bools. Follow-up patches will also make use of the flags in __free_pages_ok(). Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Wei Liu <wei.liu@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Link: https://lkml.kernel.org/r/20201005121534.15649-1-david@redhat.com Link: https://lkml.kernel.org/r/20201005121534.15649-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm: pass migratetype into memmap_init_zone() and move_pfn_range_to_zone()David Hildenbrand1-9/+12
On the memory onlining path, we want to start with MIGRATE_ISOLATE, to un-isolate the pages after memory onlining is complete. Let's allow passing in the migratetype. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Michel Lespinasse <walken@google.com> Cc: Charan Teja Reddy <charante@codeaurora.org> Cc: Mel Gorman <mgorman@techsingularity.net> Link: https://lkml.kernel.org/r/20200819175957.28465-10-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_alloc: drop stale pageblock comment in memmap_init_zone*()David Hildenbrand1-12/+2
Commit ac5d2539b238 ("mm: meminit: reduce number of times pageblocks are set during struct page init") moved the actual zone range check, leaving only the alignment check for pageblocks. Let's drop the stale comment and make the pageblock check easier to read. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Charan Teja Reddy <charante@codeaurora.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michel Lespinasse <walken@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200819175957.28465-9-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_isolation: simplify return value of start_isolate_page_range()David Hildenbrand1-1/+1
Callers no longer need the number of isolated pageblocks. Let's simplify. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Charan Teja Reddy <charante@codeaurora.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michel Lespinasse <walken@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200819175957.28465-7-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_alloc: simplify __offline_isolated_pages()David Hildenbrand1-23/+4
offline_pages() is the only user. __offline_isolated_pages() never gets called with ranges that contain memory holes and we no longer care about the return value. Drop the return value handling and all pfn_valid() checks. Update the documentation. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Charan Teja Reddy <charante@codeaurora.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michel Lespinasse <walken@google.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200819175957.28465-5-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm,hwpoison: rework soft offline for in-use pagesOscar Salvador1-28/+11
This patch changes the way we set and handle in-use poisoned pages. Until now, poisoned pages were released to the buddy allocator, trusting that the checks that take place at allocation time would act as a safe net and would skip that page. This has proved to be wrong, as we got some pfn walkers out there, like compaction, that all they care is the page to be in a buddy freelist. Although this might not be the only user, having poisoned pages in the buddy allocator seems a bad idea as we should only have free pages that are ready and meant to be used as such. Before explaining the taken approach, let us break down the kind of pages we can soft offline. - Anonymous THP (after the split, they end up being 4K pages) - Hugetlb - Order-0 pages (that can be either migrated or invalited) * Normal pages (order-0 and anon-THP) - If they are clean and unmapped page cache pages, we invalidate then by means of invalidate_inode_page(). - If they are mapped/dirty, we do the isolate-and-migrate dance. Either way, do not call put_page directly from those paths. Instead, we keep the page and send it to page_handle_poison to perform the right handling. page_handle_poison sets the HWPoison flag and does the last put_page. Down the chain, we placed a check for HWPoison page in free_pages_prepare, that just skips any poisoned page, so those pages do not end up in any pcplist/freelist. After that, we set the refcount on the page to 1 and we increment the poisoned pages counter. If we see that the check in free_pages_prepare creates trouble, we can always do what we do for free pages: - wait until the page hits buddy's freelists - take it off, and flag it The downside of the above approach is that we could race with an allocation, so by the time we want to take the page off the buddy, the page has been already allocated so we cannot soft offline it. But the user could always retry it. * Hugetlb pages - We isolate-and-migrate them After the migration has been successful, we call dissolve_free_huge_page, and we set HWPoison on the page if we succeed. Hugetlb has a slightly different handling though. While for non-hugetlb pages we cared about closing the race with an allocation, doing so for hugetlb pages requires quite some additional and intrusive code (we would need to hook in free_huge_page and some other places). So I decided to not make the code overly complicated and just fail normally if the page we allocated in the meantime. We can always build on top of this. As a bonus, because of the way we handle now in-use pages, we no longer need the put-as-isolation-migratetype dance, that was guarding for poisoned pages to end up in pcplists. Signed-off-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Aristeu Rozanski <aris@ruivo.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dmitry Yakunin <zeil@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200922135650.1634-10-osalvador@suse.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm,hwpoison: rework soft offline for free pagesOscar Salvador1-0/+68
When trying to soft-offline a free page, we need to first take it off the buddy allocator. Once we know is out of reach, we can safely flag it as poisoned. take_page_off_buddy will be used to take a page meant to be poisoned off the buddy allocator. take_page_off_buddy calls break_down_buddy_pages, which splits a higher-order page in case our page belongs to one. Once the page is under our control, we call page_handle_poison to set it as poisoned and grab a refcount on it. Signed-off-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Aristeu Rozanski <aris@ruivo.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dmitry Yakunin <zeil@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: Tony Luck <tony.luck@intel.com> Link: https://lkml.kernel.org/r/20200922135650.1634-9-osalvador@suse.de Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16mm/page_owner: change split_page_owner to take a countMatthew Wilcox (Oracle)1-1/+1
The implementation of split_page_owner() prefers a count rather than the old order of the page. When we support a variable size THP, we won't have the order at this point, but we will have the number of pages. So change the interface to what the caller and callee would prefer. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: SeongJae Park <sjpark@amazon.de> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Huang Ying <ying.huang@intel.com> Link: https://lkml.kernel.org/r/20200908195539.25896-4-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-15Merge tag 'net-next-5.10' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: - Add redirect_neigh() BPF packet redirect helper, allowing to limit stack traversal in common container configs and improving TCP back-pressure. Daniel reports ~10Gbps => ~15Gbps single stream TCP performance gain. - Expand netlink policy support and improve policy export to user space. (Ge)netlink core performs request validation according to declared policies. Expand the expressiveness of those policies (min/max length and bitmasks). Allow dumping policies for particular commands. This is used for feature discovery by user space (instead of kernel version parsing or trial and error). - Support IGMPv3/MLDv2 multicast listener discovery protocols in bridge. - Allow more than 255 IPv4 multicast interfaces. - Add support for Type of Service (ToS) reflection in SYN/SYN-ACK packets of TCPv6. - In Multi-patch TCP (MPTCP) support concurrent transmission of data on multiple subflows in a load balancing scenario. Enhance advertising addresses via the RM_ADDR/ADD_ADDR options. - Support SMC-Dv2 version of SMC, which enables multi-subnet deployments. - Allow more calls to same peer in RxRPC. - Support two new Controller Area Network (CAN) protocols - CAN-FD and ISO 15765-2:2016. - Add xfrm/IPsec compat layer, solving the 32bit user space on 64bit kernel problem. - Add TC actions for implementing MPLS L2 VPNs. - Improve nexthop code - e.g. handle various corner cases when nexthop objects are removed from groups better, skip unnecessary notifications and make it easier to offload nexthops into HW by converting to a blocking notifier. - Support adding and consuming TCP header options by BPF programs, opening the doors for easy experimental and deployment-specific TCP option use. - Reorganize TCP congestion control (CC) initialization to simplify life of TCP CC implemented in BPF. - Add support for shipping BPF programs with the kernel and loading them early on boot via the User Mode Driver mechanism, hence reusing all the user space infra we have. - Support sleepable BPF programs, initially targeting LSM and tracing. - Add bpf_d_path() helper for returning full path for given 'struct path'. - Make bpf_tail_call compatible with bpf-to-bpf calls. - Allow BPF programs to call map_update_elem on sockmaps. - Add BPF Type Format (BTF) support for type and enum discovery, as well as support for using BTF within the kernel itself (current use is for pretty printing structures). - Support listing and getting information about bpf_links via the bpf syscall. - Enhance kernel interfaces around NIC firmware update. Allow specifying overwrite mask to control if settings etc. are reset during update; report expected max time operation may take to users; support firmware activation without machine reboot incl. limits of how much impact reset may have (e.g. dropping link or not). - Extend ethtool configuration interface to report IEEE-standard counters, to limit the need for per-vendor logic in user space. - Adopt or extend devlink use for debug, monitoring, fw update in many drivers (dsa loop, ice, ionic, sja1105, qed, mlxsw, mv88e6xxx, dpaa2-eth). - In mlxsw expose critical and emergency SFP module temperature alarms. Refactor port buffer handling to make the defaults more suitable and support setting these values explicitly via the DCBNL interface. - Add XDP support for Intel's igb driver. - Support offloading TC flower classification and filtering rules to mscc_ocelot switches. - Add PTP support for Marvell Octeontx2 and PP2.2 hardware, as well as fixed interval period pulse generator and one-step timestamping in dpaa-eth. - Add support for various auth offloads in WiFi APs, e.g. SAE (WPA3) offload. - Add Lynx PHY/PCS MDIO module, and convert various drivers which have this HW to use it. Convert mvpp2 to split PCS. - Support Marvell Prestera 98DX3255 24-port switch ASICs, as well as 7-port Mediatek MT7531 IP. - Add initial support for QCA6390 and IPQ6018 in ath11k WiFi driver, and wcn3680 support in wcn36xx. - Improve performance for packets which don't require much offloads on recent Mellanox NICs by 20% by making multiple packets share a descriptor entry. - Move chelsio inline crypto drivers (for TLS and IPsec) from the crypto subtree to drivers/net. Move MDIO drivers out of the phy directory. - Clean up a lot of W=1 warnings, reportedly the actively developed subsections of networking drivers should now build W=1 warning free. - Make sure drivers don't use in_interrupt() to dynamically adapt their code. Convert tasklets to use new tasklet_setup API (sadly this conversion is not yet complete). * tag 'net-next-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2583 commits) Revert "bpfilter: Fix build error with CONFIG_BPFILTER_UMH" net, sockmap: Don't call bpf_prog_put() on NULL pointer bpf, selftest: Fix flaky tcp_hdr_options test when adding addr to lo bpf, sockmap: Add locking annotations to iterator netfilter: nftables: allow re-computing sctp CRC-32C in 'payload' statements net: fix pos incrementment in ipv6_route_seq_next net/smc: fix invalid return code in smcd_new_buf_create() net/smc: fix valid DMBE buffer sizes net/smc: fix use-after-free of delayed events bpfilter: Fix build error with CONFIG_BPFILTER_UMH cxgb4/ch_ipsec: Replace the module name to ch_ipsec from chcr net: sched: Fix suspicious RCU usage while accessing tcf_tunnel_info bpf: Fix register equivalence tracking. rxrpc: Fix loss of final ack on shutdown rxrpc: Fix bundle counting for exclusive connections netfilter: restore NF_INET_NUMHOOKS ibmveth: Identify ingress large send packets. ibmveth: Switch order of ibmveth_helper calls. cxgb4: handle 4-tuple PEDIT to NAT mode translation selftests: Add VRF route leaking tests ...
2020-10-13memblock: use separate iterators for memory and reserved regionsMike Rapoport1-4/+4
for_each_memblock() is used to iterate over memblock.memory in a few places that use data from memblock_region rather than the memory ranges. Introduce separate for_each_mem_region() and for_each_reserved_mem_region() to improve encapsulation of memblock internals from its users. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Ingo Molnar <mingo@kernel.org> [x86] Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> [MIPS] Acked-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> [.clang-format] Cc: Andy Lutomirski <luto@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Axtens <dja@axtens.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Emil Renner Berthing <kernel@esmil.dk> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20200818151634.14343-18-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13memblock: reduce number of parameters in for_each_mem_range()Mike Rapoport1-2/+1
Currently for_each_mem_range() and for_each_mem_range_rev() iterators are the most generic way to traverse memblock regions. As such, they have 8 parameters and they are hardly convenient to users. Most users choose to utilize one of their wrappers and the only user that actually needs most of the parameters is memblock itself. To avoid yet another naming for memblock iterators, rename the existing for_each_mem_range[_rev]() to __for_each_mem_range[_rev]() and add a new for_each_mem_range[_rev]() wrappers with only index, start and end parameters. The new wrapper nicely fits into init_unavailable_mem() and will be used in upcoming changes to simplify memblock traversals. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> [MIPS] Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Axtens <dja@axtens.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Emil Renner Berthing <kernel@esmil.dk> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20200818151634.14343-11-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc.c: fix freeing non-compound pagesMatthew Wilcox (Oracle)1-0/+3
Here is a very rare race which leaks memory: Page P0 is allocated to the page cache. Page P1 is free. Thread A Thread B Thread C find_get_entry(): xas_load() returns P0 Removes P0 from page cache P0 finds its buddy P1 alloc_pages(GFP_KERNEL, 1) returns P0 P0 has refcount 1 page_cache_get_speculative(P0) P0 has refcount 2 __free_pages(P0) P0 has refcount 1 put_page(P0) P1 is not freed Fix this by freeing all the pages in __free_pages() that won't be freed by the call to put_page(). It's usually not a good idea to split a page, but this is a very unlikely scenario. Fixes: e286781d5f2e ("mm: speculative page references") Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20200926213919.26642-1-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mmzone: clean code by removing unused macro parameterMateusz Nosek1-2/+2
Previously 'for_next_zone_zonelist_nodemask' macro parameter 'zlist' was unused so this patch removes it. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200917211906.30059-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc.c: __perform_reclaim should return 'unsigned long'Yanfei Xu1-3/+2
__perform_reclaim()'s single caller expects it to return 'unsigned long', hence change its return value and a local variable to 'unsigned long'. Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200916022138.16740-1-yanfei.xu@windriver.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc.c: clean code by merging two functionsMateusz Nosek1-8/+2
finalise_ac() is just 'epilogue' for 'prepare_alloc_pages'. Therefore there is no need to keep them both so 'finalise_ac' content can be merged into prepare_alloc_pages() code. It would make __alloc_pages_nodemask() cleaner when it comes to readability. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@kernel.org> Link: https://lkml.kernel.org/r/20200916110118.6537-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc.c: fix early params garbage value accessesMateusz Nosek1-6/+6
Previously in '__init early_init_on_alloc' and '__init early_init_on_free' the return values from 'kstrtobool' were not handled properly. That caused potential garbage value read from variable 'bool_result'. Introduced patch fixes error handling. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200916214125.28271-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc.c: micro-optimization remove unnecessary branchMateusz Nosek1-5/+3
Previously flags check was separated into two separated checks with two separated branches. In case of presence of any of two mentioned flags, the same effect on flow occurs. Therefore checks can be merged and one branch can be avoided. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200911092310.31136-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc.c: clean code by removing unnecessary initializationMateusz Nosek1-3/+1
Previously variable 'tmp' was initialized, but was not read later before reassigning. So the initialization can be removed. [akpm@linux-foundation.org: remove `tmp' altogether] Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: https://lkml.kernel.org/r/20200904132422.17387-1-mateusznosek0@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm, isolation: avoid checking unmovable pages across pageblock boundaryLi Xinhai1-1/+2
In has_unmovable_pages(), the page parameter would not always be the first page within a pageblock (see how the page pointer is passed in from start_isolate_page_range() after call __first_valid_page()), so that would cause checking unmovable pages span two pageblocks. After this patch, the checking is enforced within one pageblock no matter the page is first one or not, and obey the semantics of this function. This issue is found by code inspection. Michal said "this might lead to false negatives when an unrelated block would cause an isolation failure". Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Hildenbrand <david@redhat.com> Link: https://lkml.kernel.org/r/20200824065811.383266-1-lixinhai.lxh@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-13mm/page_alloc: tweak comments in has_unmovable_pages()David Hildenbrand1-16/+6
Patch series "mm / virtio-mem: support ZONE_MOVABLE", v5. When introducing virtio-mem, the semantics of ZONE_MOVABLE were rather unclear, which is why we special-cased ZONE_MOVABLE such that partially plugged blocks would never end up in ZONE_MOVABLE. Now that the semantics are much clearer (and are documented in patch #6), let's support partially plugged memory blocks in ZONE_MOVABLE, allowing partially plugged memory blocks to be online to ZONE_MOVABLE and also unplugging from such memory blocks. This avoids surprises when onlining of memory blocks suddenly fails, just because they are not completely populated by virtio-mem (yet). This is especially helpful for testing, but also paves the way for virtio-mem optimizations, allowing more memory to get reliably unplugged. Cleanup has_unmovable_pages() and set_migratetype_isolate(), providing better documentation of how ZONE_MOVABLE interacts with different kind of unmovable pages (memory offlining vs. alloc_contig_range()). This patch (of 6): Let's move the split comment regarding bootmem allocations and memory holes, especially in the context of ZONE_MOVABLE, to the PageReserved() check. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Qian Cai <cai@lca.pw> Link: http://lkml.kernel.org/r/20200816125333.7434-1-david@redhat.com Link: http://lkml.kernel.org/r/20200816125333.7434-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-11mm: khugepaged: recalculate min_free_kbytes after memory hotplug as expected ↵Vijay Balakrishna1-0/+3
by khugepaged When memory is hotplug added or removed the min_free_kbytes should be recalculated based on what is expected by khugepaged. Currently after hotplug, min_free_kbytes will be set to a lower default and higher default set when THP enabled is lost. This change restores min_free_kbytes as expected for THP consumers. [vijayb@linux.microsoft.com: v5] Link: https://lkml.kernel.org/r/1601398153-5517-1-git-send-email-vijayb@linux.microsoft.com Fixes: f000565adb77 ("thp: set recommended min free kbytes") Signed-off-by: Vijay Balakrishna <vijayb@linux.microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Allen Pais <apais@microsoft.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Song Liu <songliubraving@fb.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/1600305709-2319-2-git-send-email-vijayb@linux.microsoft.com Link: https://lkml.kernel.org/r/1600204258-13683-1-git-send-email-vijayb@linux.microsoft.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller1-8/+21
Rejecting non-native endian BTF overlapped with the addition of support for it. The rest were more simple overlapping changes, except the renesas ravb binding update, which had to follow a file move as well as a YAML conversion. Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03mm/page_alloc: handle a missing case for memalloc_nocma_{save/restore} APIsJoonsoo Kim1-3/+16
memalloc_nocma_{save/restore} APIs can be used to skip page allocation on CMA area, but, there is a missing case and the page on CMA area could be allocated even if APIs are used. This patch handles this case to fix the potential issue. For now, these APIs are used to prevent long-term pinning on the CMA page. When the long-term pinning is requested on the CMA page, it is migrated to the non-CMA page before pinning. This non-CMA page is allocated by using memalloc_nocma_{save/restore} APIs. If APIs doesn't work as intended, the CMA page is allocated and it is pinned for a long time. This long-term pin for the CMA page causes cma_alloc() failure and it could result in wrong behaviour on the device driver who uses the cma_alloc(). Missing case is an allocation from the pcplist. MIGRATE_MOVABLE pcplist could have the pages on CMA area so we need to skip it if ALLOC_CMA isn't specified. Fixes: 8510e69c8efe (mm/page_alloc: fix memalloc_nocma_{save/restore} APIs) Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Cc: Mel Gorman <mgorman@techsingularity.net> Link: https://lkml.kernel.org/r/1601429472-12599-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-26mm: replace memmap_context by meminit_contextLaurent Dufour1-5/+5
Patch series "mm: fix memory to node bad links in sysfs", v3. Sometimes, firmware may expose interleaved memory layout like this: Early memory node ranges node 1: [mem 0x0000000000000000-0x000000011fffffff] node 2: [mem 0x0000000120000000-0x000000014fffffff] node 1: [mem 0x0000000150000000-0x00000001ffffffff] node 0: [mem 0x0000000200000000-0x000000048fffffff] node 2: [mem 0x0000000490000000-0x00000007ffffffff] In that case, we can see memory blocks assigned to multiple nodes in sysfs: $ ls -l /sys/devices/system/memory/memory21 total 0 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node1 -> ../../node/node1 lrwxrwxrwx 1 root root 0 Aug 24 05:27 node2 -> ../../node/node2 -rw-r--r-- 1 root root 65536 Aug 24 05:27 online -r--r--r-- 1 root root 65536 Aug 24 05:27 phys_device -r--r--r-- 1 root root 65536 Aug 24 05:27 phys_index drwxr-xr-x 2 root root 0 Aug 24 05:27 power -r--r--r-- 1 root root 65536 Aug 24 05:27 removable -rw-r--r-- 1 root root 65536 Aug 24 05:27 state lrwxrwxrwx 1 root root 0 Aug 24 05:25 subsystem -> ../../../../bus/memory -rw-r--r-- 1 root root 65536 Aug 24 05:25 uevent -r--r--r-- 1 root root 65536 Aug 24 05:27 valid_zones The same applies in the node's directory with a memory21 link in both the node1 and node2's directory. This is wrong but doesn't prevent the system to run. However when later, one of these memory blocks is hot-unplugged and then hot-plugged, the system is detecting an inconsistency in the sysfs layout and a BUG_ON() is raised: kernel BUG at /Users/laurent/src/linux-ppc/mm/memory_hotplug.c:1084! LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp pseries_rng rng_core vmx_crypto gf128mul binfmt_misc ip_tables x_tables xfs libcrc32c crc32c_vpmsum autofs4 CPU: 8 PID: 10256 Comm: drmgr Not tainted 5.9.0-rc1+ #25 Call Trace: add_memory_resource+0x23c/0x340 (unreliable) __add_memory+0x5c/0xf0 dlpar_add_lmb+0x1b4/0x500 dlpar_memory+0x1f8/0xb80 handle_dlpar_errorlog+0xc0/0x190 dlpar_store+0x198/0x4a0 kobj_attr_store+0x30/0x50 sysfs_kf_write+0x64/0x90 kernfs_fop_write+0x1b0/0x290 vfs_write+0xe8/0x290 ksys_write+0xdc/0x130 system_call_exception+0x160/0x270 system_call_common+0xf0/0x27c This has been seen on PowerPC LPAR. The root cause of this issue is that when node's memory is registered, the range used can overlap another node's range, thus the memory block is registered to multiple nodes in sysfs. There are two issues here: (a) The sysfs memory and node's layouts are broken due to these multiple links (b) The link errors in link_mem_sections() should not lead to a system panic. To address (a) register_mem_sect_under_node should not rely on the system state to detect whether the link operation is triggered by a hot plug operation or not. This is addressed by the patches 1 and 2 of this series. Issue (b) will be addressed separately. This patch (of 2): The memmap_context enum is used to detect whether a memory operation is due to a hot-add operation or happening at boot time. Make it general to the hotplug operation and rename it as meminit_context. There is no functional change introduced by this patch Suggested-by: David Hildenbrand <david@redhat.com> Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Rafael J . Wysocki" <rafael@kernel.org> Cc: Nathan Lynch <nathanl@linux.ibm.com> Cc: Scott Cheloha <cheloha@linux.ibm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20200915094143.79181-1-ldufour@linux.ibm.com Link: https://lkml.kernel.org/r/20200915132624.9723-1-ldufour@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-09-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller1-1/+1
Daniel Borkmann says: ==================== pull-request: bpf-next 2020-09-01 The following pull-request contains BPF updates for your *net-next* tree. There are two small conflicts when pulling, resolve as follows: 1) Merge conflict in tools/lib/bpf/libbpf.c between 88a82120282b ("libbpf: Factor out common ELF operations and improve logging") in bpf-next and 1e891e513e16 ("libbpf: Fix map index used in error message") in net-next. Resolve by taking the hunk in bpf-next: [...] scn = elf_sec_by_idx(obj, obj->efile.btf_maps_shndx); data = elf_sec_data(obj, scn); if (!scn || !data) { pr_warn("elf: failed to get %s map definitions for %s\n", MAPS_ELF_SEC, obj->path); return -EINVAL; } [...] 2) Merge conflict in drivers/net/ethernet/mellanox/mlx5/core/en/xsk/rx.c between 9647c57b11e5 ("xsk: i40e: ice: ixgbe: mlx5: Test for dma_need_sync earlier for better performance") in bpf-next and e20f0dbf204f ("net/mlx5e: RX, Add a prefetch command for small L1_CACHE_BYTES") in net-next. Resolve the two locations by retaining net_prefetch() and taking xsk_buff_dma_sync_for_cpu() from bpf-next. Should look like: [...] xdp_set_data_meta_invalid(xdp); xsk_buff_dma_sync_for_cpu(xdp, rq->xsk_pool); net_prefetch(xdp->data); [...] We've added 133 non-merge commits during the last 14 day(s) which contain a total of 246 files changed, 13832 insertions(+), 3105 deletions(-). The main changes are: 1) Initial support for sleepable BPF programs along with bpf_copy_from_user() helper for tracing to reliably access user memory, from Alexei Starovoitov. 2) Add BPF infra for writing and parsing TCP header options, from Martin KaFai Lau. 3) bpf_d_path() helper for returning full path for given 'struct path', from Jiri Olsa. 4) AF_XDP support for shared umems between devices and queues, from Magnus Karlsson. 5) Initial prep work for full BPF-to-BPF call support in libbpf, from Andrii Nakryiko. 6) Generalize bpf_sk_storage map & add local storage for inodes, from KP Singh. 7) Implement sockmap/hash updates from BPF context, from Lorenz Bauer. 8) BPF xor verification for scalar types & add BPF link iterator, from Yonghong Song. 9) Use target's prog type for BPF_PROG_TYPE_EXT prog verification, from Udip Pant. 10) Rework BPF tracing samples to use libbpf loader, from Daniel T. Lee. 11) Fix xdpsock sample to really cycle through all buffers, from Weqaar Janjua. 12) Improve type safety for tun/veth XDP frame handling, from Maciej Żenczykowski. 13) Various smaller cleanups and improvements all over the place. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-28mm/error_inject: Fix allow_error_inject function signatures.Alexei Starovoitov1-1/+1
'static' and 'static noinline' function attributes make no guarantees that gcc/clang won't optimize them. The compiler may decide to inline 'static' function and in such case ALLOW_ERROR_INJECT becomes meaningless. The compiler could have inlined __add_to_page_cache_locked() in one callsite and didn't inline in another. In such case injecting errors into it would cause unpredictable behavior. It's worse with 'static noinline' which won't be inlined, but it still can be optimized. Like the compiler may decide to remove one argument or constant propagate the value depending on the callsite. To avoid such issues make sure that these functions are global noinline. Fixes: af3b854492f3 ("mm/page_alloc.c: allow error injection") Fixes: cfcbfb1382db ("mm/filemap.c: enable error injection at add_to_page_cache()") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Link: https://lore.kernel.org/bpf/20200827220114.69225-2-alexei.starovoitov@gmail.com
2020-08-21mm, page_alloc: fix core hung in free_pcppages_bulk()Charan Teja Reddy1-0/+5
The following race is observed with the repeated online, offline and a delay between two successive online of memory blocks of movable zone. P1 P2 Online the first memory block in the movable zone. The pcp struct values are initialized to default values,i.e., pcp->high = 0 & pcp->batch = 1. Allocate the pages from the movable zone. Try to Online the second memory block in the movable zone thus it entered the online_pages() but yet to call zone_pcp_update(). This process is entered into the exit path thus it tries to release the order-0 pages to pcp lists through free_unref_page_commit(). As pcp->high = 0, pcp->count = 1 proceed to call the function free_pcppages_bulk(). Update the pcp values thus the new pcp values are like, say, pcp->high = 378, pcp->batch = 63. Read the pcp's batch value using READ_ONCE() and pass the same to free_pcppages_bulk(), pcp values passed here are, batch = 63, count = 1. Since num of pages in the pcp lists are less than ->batch, then it will stuck in while(list_empty(list)) loop with interrupts disabled thus a core hung. Avoid this by ensuring free_pcppages_bulk() is called with proper count of pcp list pages. The mentioned race is some what easily reproducible without [1] because pcp's are not updated for the first memory block online and thus there is a enough race window for P2 between alloc+free and pcp struct values update through onlining of second memory block. With [1], the race still exists but it is very narrow as we update the pcp struct values for the first memory block online itself. This is not limited to the movable zone, it could also happen in cases with the normal zone (e.g., hotplug to a node that only has DMA memory, or no other memory yet). [1]: https://patchwork.kernel.org/patch/11696389/ Fixes: 5f8dcc21211a ("page-allocator: split per-cpu list into one-list-per-migrate-type") Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: <stable@vger.kernel.org> [2.6+] Link: http://lkml.kernel.org/r/1597150703-19003-1-git-send-email-charante@codeaurora.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-21mm: include CMA pages in lowmem_reserve at bootDoug Berger1-1/+1
The lowmem_reserve arrays provide a means of applying pressure against allocations from lower zones that were targeted at higher zones. Its values are a function of the number of pages managed by higher zones and are assigned by a call to the setup_per_zone_lowmem_reserve() function. The function is initially called at boot time by the function init_per_zone_wmark_min() and may be called later by accesses of the /proc/sys/vm/lowmem_reserve_ratio sysctl file. The function init_per_zone_wmark_min() was moved up from a module_init to a core_initcall to resolve a sequencing issue with khugepaged. Unfortunately this created a sequencing issue with CMA page accounting. The CMA pages are added to the managed page count of a zone when cma_init_reserved_areas() is called at boot also as a core_initcall. This makes it uncertain whether the CMA pages will be added to the managed page counts of their zones before or after the call to init_per_zone_wmark_min() as it becomes dependent on link order. With the current link order the pages are added to the managed count after the lowmem_reserve arrays are initialized at boot. This means the lowmem_reserve values at boot may be lower than the values used later if /proc/sys/vm/lowmem_reserve_ratio is accessed even if the ratio values are unchanged. In many cases the difference is not significant, but for example an ARM platform with 1GB of memory and the following memory layout cma: Reserved 256 MiB at 0x0000000030000000 Zone ranges: DMA [mem 0x0000000000000000-0x000000002fffffff] Normal empty HighMem [mem 0x0000000030000000-0x000000003fffffff] would result in 0 lowmem_reserve for the DMA zone. This would allow userspace to deplete the DMA zone easily. Funnily enough $ cat /proc/sys/vm/lowmem_reserve_ratio would fix up the situation because as a side effect it forces setup_per_zone_lowmem_reserve. This commit breaks the link order dependency by invoking init_per_zone_wmark_min() as a postcore_initcall so that the CMA pages have the chance to be properly accounted in their zone(s) and allowing the lowmem_reserve arrays to receive consistent values. Fixes: bc22af74f271 ("mm: update min_free_kbytes from khugepaged after core initialization") Signed-off-by: Doug Berger <opendmb@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Jason Baron <jbaron@akamai.com> Cc: David Rientjes <rientjes@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1597423766-27849-1-git-send-email-opendmb@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-14mm: store compound_nr as well as compound_orderMatthew Wilcox (Oracle)1-2/+3
Patch series "THP prep patches". These are some generic cleanups and improvements, which I would like merged into mmotm soon. The first one should be a performance improvement for all users of compound pages, and the others are aimed at getting code to compile away when CONFIG_TRANSPARENT_HUGEPAGE is disabled (ie small systems). Also better documented / less confusing than the current prefix mixture of compound, hpage and thp. This patch (of 7): This removes a few instructions from functions which need to know how many pages are in a compound page. The storage used is either page->mapping on 64-bit or page->index on 32-bit. Both of these are fine to overlay on tail pages. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Link: http://lkml.kernel.org/r/20200629151959.15779-1-willy@infradead.org Link: http://lkml.kernel.org/r/20200629151959.15779-2-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12mm/page_alloc: remove a wrapper for alloc_migration_target()Joonsoo Kim1-2/+6
There is a well-defined standard migration target callback. Use it directly. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Roman Gushchin <guro@fb.com> Link: http://lkml.kernel.org/r/1594622517-20681-8-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-12mm/page_alloc.c: delete or fix duplicated wordsRandy Dunlap1-3/+3
Drop the repeated word "them" and "that". Change "the the" to "to the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Link: http://lkml.kernel.org/r/20200801173822.14973-10-rdunlap@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc: fix memalloc_nocma_{save/restore} APIsJoonsoo Kim1-10/+21
Currently, memalloc_nocma_{save/restore} API that prevents CMA area in page allocation is implemented by using current_gfp_context(). However, there are two problems of this implementation. First, this doesn't work for allocation fastpath. In the fastpath, original gfp_mask is used since current_gfp_context() is introduced in order to control reclaim and it is on slowpath. So, CMA area can be allocated through the allocation fastpath even if memalloc_nocma_{save/restore} APIs are used. Currently, there is just one user for these APIs and it has a fallback method to prevent actual problem. Second, clearing __GFP_MOVABLE in current_gfp_context() has a side effect to exclude the memory on the ZONE_MOVABLE for allocation target. To fix these problems, this patch changes the implementation to exclude CMA area in page allocation. Main point of this change is using the alloc_flags. alloc_flags is mainly used to control allocation so it fits for excluding CMA area in allocation. Fixes: d7fefcc8de91 (mm/cma: add PF flag to force non cma alloc) Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Cc: Roman Gushchin <guro@fb.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com> Link: http://lkml.kernel.org/r/1595468942-29687-1-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc.c: skip setting nodemask when we are in interruptMuchun Song1-1/+5
When we are in the interrupt context, it is irrelevant to the current task context. If we use current task's mems_allowed, we can be fair to alloc pages in the fast path and fall back to slow path memory allocation when the current node(which is the current task mems_allowed) does not have enough memory to allocate. In this case, it slows down the memory allocation speed of interrupt context. So we can skip setting the nodemask to allow any node to allocate memory, so that fast path allocation can success. Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Cc: David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/20200706025921.53683-1-songmuchun@bytedance.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc: fallbacks at most has 3 elementsWei Yang1-1/+1
MIGRAGE_TYPES is used to be the mark of end and there are at most 3 elements for the one dimension array. Reduce to 3 to save little memory. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Link: http://lkml.kernel.org/r/20200625231022.18784-1-richard.weiyang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc: silence a KASAN false positiveQian Cai1-0/+3
kernel_init_free_pages() will use memset() on s390 to clear all pages from kmalloc_order() which will override KASAN redzones because a redzone was setup from the end of the allocation size to the end of the last page. Silence it by not reporting it there. An example of the report is, BUG: KASAN: slab-out-of-bounds in __free_pages_ok Write of size 4096 at addr 000000014beaa000 Call Trace: show_stack+0x152/0x210 dump_stack+0x1f8/0x248 print_address_description.isra.13+0x5e/0x4d0 kasan_report+0x130/0x178 check_memory_region+0x190/0x218 memset+0x34/0x60 __free_pages_ok+0x894/0x12f0 kfree+0x4f2/0x5e0 unpack_to_rootfs+0x60e/0x650 populate_rootfs+0x56/0x358 do_one_initcall+0x1f4/0xa20 kernel_init_freeable+0x758/0x7e8 kernel_init+0x1c/0x170 ret_from_fork+0x24/0x28 Memory state around the buggy address: 000000014bea9f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 000000014bea9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >000000014beaa000: 03 fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe ^ 000000014beaa080: fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe 000000014beaa100: fe fe fe fe fe fe fe fe fe fe fe fe fe fe Fixes: 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options") Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: Vasily Gorbik <gor@linux.ibm.com> Acked-by: Vasily Gorbik <gor@linux.ibm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Link: http://lkml.kernel.org/r/20200610052154.5180-1-cai@lca.pw Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc.c: remove unnecessary end_bitidx for ↵Wei Yang1-10/+5
[set|get]_pfnblock_flags_mask() After previous cleanup, the end_bitidx is not necessary any more. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/20200623124201.8199-4-richard.weiyang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc.c: simplify pageblock bitmap accessWei Yang1-7/+6
Due to commit e58469bafd05 ("mm: page_alloc: use word-based accesses for get/set pageblock bitmaps"), pageblock bitmap is accessed with word-based access. This operation could be simplified a little. Intuitively, if we want to get a bit range [start_idx, end_idx] in a word, we can do like this: mask = (1 << (end_bitidx - start_bitidx + 1)) - 1; ret = (word >> start_idx) & mask; And also if we want to set a bit range [start_idx, end_idx] with flags, we can do the same by just shift start_bitidx. By doing so we reduce some instructions for these two helper functions: Before Patched set_pfnblock_flags_mask 209 198(-5%) get_pfnblock_flags_mask 101 87(-13%) Since the syntax is changed a little, we need to check the whole 4-bit migrate_type instead of part of it. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/20200623124201.8199-3-richard.weiyang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc.c: extract the common part in pfn_to_bitidx()Wei Yang1-2/+1
The return value calculation is the same both for SPARSEMEM or not. Just take it out. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/20200623124201.8199-2-richard.weiyang@linux.alibaba.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/page_alloc: remove nr_free_pagecache_pages()David Hildenbrand1-14/+2
nr_free_pagecache_pages() isn't used outside page_alloc.c anymore - and the name does not really help to understand what's going on. Let's open-code it instead and add a comment. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Huang Ying <ying.huang@intel.com> Link: http://lkml.kernel.org/r/20200619132410.23859-3-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm: remove vm_total_pagesDavid Hildenbrand1-0/+2
The global variable "vm_total_pages" is a relic from older days. There is only a single user that reads the variable - build_all_zonelists() - and the first thing it does is update it. Use a local variable in build_all_zonelists() instead and remove the global variable. Signed-off-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Minchan Kim <minchan@kernel.org> Link: http://lkml.kernel.org/r/20200619132410.23859-2-david@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm, page_alloc: skip ->waternark_boost for atomic order-0 allocationsCharan Teja Reddy1-4/+20
When boosting is enabled, it is observed that rate of atomic order-0 allocation failures are high due to the fact that free levels in the system are checked with ->watermark_boost offset. This is not a problem for sleepable allocations but for atomic allocations which looks like regression. This problem is seen frequently on system setup of Android kernel running on Snapdragon hardware with 4GB RAM size. When no extfrag event occurred in the system, ->watermark_boost factor is zero, thus the watermark configurations in the system are: _watermark = ( [WMARK_MIN] = 1272, --> ~5MB [WMARK_LOW] = 9067, --> ~36MB [WMARK_HIGH] = 9385), --> ~38MB watermark_boost = 0 After launching some memory hungry applications in Android which can cause extfrag events in the system to an extent that ->watermark_boost can be set to max i.e. default boost factor makes it to 150% of high watermark. _watermark = ( [WMARK_MIN] = 1272, --> ~5MB [WMARK_LOW] = 9067, --> ~36MB [WMARK_HIGH] = 9385), --> ~38MB watermark_boost = 14077, -->~57MB With default system configuration, for an atomic order-0 allocation to succeed, having free memory of ~2MB will suffice. But boosting makes the min_wmark to ~61MB thus for an atomic order-0 allocation to be successful system should have minimum of ~23MB of free memory(from calculations of zone_watermark_ok(), min = 3/4(min/2)). But failures are observed despite system is having ~20MB of free memory. In the testing, this is reproducible as early as first 300secs since boot and with furtherlowram configurations(<2GB) it is observed as early as first 150secs since boot. These failures can be avoided by excluding the ->watermark_boost in watermark caluculations for atomic order-0 allocations. [akpm@linux-foundation.org: fix comment grammar, reflow comment] [charante@codeaurora.org: fix suggested by Mel Gorman] Link: http://lkml.kernel.org/r/31556793-57b1-1c21-1a9d-22674d9bd938@codeaurora.org Signed-off-by: Charan Teja Reddy <charante@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Mel Gorman <mgorman@techsingularity.net> Link: http://lkml.kernel.org/r/1589882284-21010-1-git-send-email-charante@codeaurora.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07page_alloc: consider highatomic reserve in watermark fastJaewon Kim1-30/+36
zone_watermark_fast was introduced by commit 48ee5f3696f6 ("mm, page_alloc: shortcut watermark checks for order-0 pages"). The commit simply checks if free pages is bigger than watermark without additional calculation such like reducing watermark. It considered free cma pages but it did not consider highatomic reserved. This may incur exhaustion of free pages except high order atomic free pages. Assume that reserved_highatomic pageblock is bigger than watermark min, and there are only few free pages except high order atomic free. Because zone_watermark_fast passes the allocation without considering high order atomic free, normal reclaimable allocation like GFP_HIGHUSER will consume all the free pages. Then finally order-0 atomic allocation may fail on allocation. This means watermark min is not protected against non-atomic allocation. The order-0 atomic allocation with ALLOC_HARDER unwantedly can be failed. Additionally the __GFP_MEMALLOC allocation with ALLOC_NO_WATERMARKS also can be failed. To avoid the problem, zone_watermark_fast should consider highatomic reserve. If the actual size of high atomic free is counted accurately like cma free, we may use it. On this patch just use nr_reserved_highatomic. Additionally introduce __zone_watermark_unusable_free to factor out common parts between zone_watermark_fast and __zone_watermark_ok. This is an example of ALLOC_HARDER allocation failure using v4.19 based kernel. Binder:9343_3: page allocation failure: order:0, mode:0x480020(GFP_ATOMIC), nodemask=(null) Call trace: [<ffffff8008f40f8c>] dump_stack+0xb8/0xf0 [<ffffff8008223320>] warn_alloc+0xd8/0x12c [<ffffff80082245e4>] __alloc_pages_nodemask+0x120c/0x1250 [<ffffff800827f6e8>] new_slab+0x128/0x604 [<ffffff800827b0cc>] ___slab_alloc+0x508/0x670 [<ffffff800827ba00>] __kmalloc+0x2f8/0x310 [<ffffff80084ac3e0>] context_struct_to_string+0x104/0x1cc [<ffffff80084ad8fc>] security_sid_to_context_core+0x74/0x144 [<ffffff80084ad880>] security_sid_to_context+0x10/0x18 [<ffffff800849bd80>] selinux_secid_to_secctx+0x20/0x28 [<ffffff800849109c>] security_secid_to_secctx+0x3c/0x70 [<ffffff8008bfe118>] binder_transaction+0xe68/0x454c Mem-Info: active_anon:102061 inactive_anon:81551 isolated_anon:0 active_file:59102 inactive_file:68924 isolated_file:64 unevictable:611 dirty:63 writeback:0 unstable:0 slab_reclaimable:13324 slab_unreclaimable:44354 mapped:83015 shmem:4858 pagetables:26316 bounce:0 free:2727 free_pcp:1035 free_cma:178 Node 0 active_anon:408244kB inactive_anon:326204kB active_file:236408kB inactive_file:275696kB unevictable:2444kB isolated(anon):0kB isolated(file):256kB mapped:332060kB dirty:252kB writeback:0kB shmem:19432kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no Normal free:10908kB min:6192kB low:44388kB high:47060kB active_anon:409160kB inactive_anon:325924kB active_file:235820kB inactive_file:276628kB unevictable:2444kB writepending:252kB present:3076096kB managed:2673676kB mlocked:2444kB kernel_stack:62512kB pagetables:105264kB bounce:0kB free_pcp:4140kB local_pcp:40kB free_cma:712kB lowmem_reserve[]: 0 0 Normal: 505*4kB (H) 357*8kB (H) 201*16kB (H) 65*32kB (H) 1*64kB (H) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 10236kB 138826 total pagecache pages 5460 pages in swap cache Swap cache stats: add 8273090, delete 8267506, find 1004381/4060142 This is an example of ALLOC_NO_WATERMARKS allocation failure using v4.14 based kernel. kswapd0: page allocation failure: order:0, mode:0x140000a(GFP_NOIO|__GFP_HIGHMEM|__GFP_MOVABLE), nodemask=(null) kswapd0 cpuset=/ mems_allowed=0 CPU: 4 PID: 1221 Comm: kswapd0 Not tainted 4.14.113-18770262-userdebug #1 Call trace: [<0000000000000000>] dump_backtrace+0x0/0x248 [<0000000000000000>] show_stack+0x18/0x20 [<0000000000000000>] __dump_stack+0x20/0x28 [<0000000000000000>] dump_stack+0x68/0x90 [<0000000000000000>] warn_alloc+0x104/0x198 [<0000000000000000>] __alloc_pages_nodemask+0xdc0/0xdf0 [<0000000000000000>] zs_malloc+0x148/0x3d0 [<0000000000000000>] zram_bvec_rw+0x410/0x798 [<0000000000000000>] zram_rw_page+0x88/0xdc [<0000000000000000>] bdev_write_page+0x70/0xbc [<0000000000000000>] __swap_writepage+0x58/0x37c [<0000000000000000>] swap_writepage+0x40/0x4c [<0000000000000000>] shrink_page_list+0xc30/0xf48 [<0000000000000000>] shrink_inactive_list+0x2b0/0x61c [<0000000000000000>] shrink_node_memcg+0x23c/0x618 [<0000000000000000>] shrink_node+0x1c8/0x304 [<0000000000000000>] kswapd+0x680/0x7c4 [<0000000000000000>] kthread+0x110/0x120 [<0000000000000000>] ret_from_fork+0x10/0x18 Mem-Info: active_anon:111826 inactive_anon:65557 isolated_anon:0\x0a active_file:44260 inactive_file:83422 isolated_file:0\x0a unevictable:4158 dirty:117 writeback:0 unstable:0\x0a slab_reclaimable:13943 slab_unreclaimable:43315\x0a mapped:102511 shmem:3299 pagetables:19566 bounce:0\x0a free:3510 free_pcp:553 free_cma:0 Node 0 active_anon:447304kB inactive_anon:262228kB active_file:177040kB inactive_file:333688kB unevictable:16632kB isolated(anon):0kB isolated(file):0kB mapped:410044kB d irty:468kB writeback:0kB shmem:13196kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no Normal free:14040kB min:7440kB low:94500kB high:98136kB reserved_highatomic:32768KB active_anon:447336kB inactive_anon:261668kB active_file:177572kB inactive_file:333768k B unevictable:16632kB writepending:480kB present:4081664kB managed:3637088kB mlocked:16632kB kernel_stack:47072kB pagetables:78264kB bounce:0kB free_pcp:2280kB local_pcp:720kB free_cma:0kB [ 4738.329607] lowmem_reserve[]: 0 0 Normal: 860*4kB (H) 453*8kB (H) 180*16kB (H) 26*32kB (H) 34*64kB (H) 6*128kB (H) 2*256kB (H) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 14232kB This is trace log which shows GFP_HIGHUSER consumes free pages right before ALLOC_NO_WATERMARKS. <...>-22275 [006] .... 889.213383: mm_page_alloc: page=00000000d2be5665 pfn=970744 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213385: mm_page_alloc: page=000000004b2335c2 pfn=970745 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213387: mm_page_alloc: page=00000000017272e1 pfn=970278 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213389: mm_page_alloc: page=00000000c4be79fb pfn=970279 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213391: mm_page_alloc: page=00000000f8a51d4f pfn=970260 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213393: mm_page_alloc: page=000000006ba8f5ac pfn=970261 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213395: mm_page_alloc: page=00000000819f1cd3 pfn=970196 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO <...>-22275 [006] .... 889.213396: mm_page_alloc: page=00000000f6b72a64 pfn=970197 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO kswapd0-1207 [005] ...1 889.213398: mm_page_alloc: page= (null) pfn=0 order=0 migratetype=1 nr_free=3650 gfp_flags=GFP_NOWAIT|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_MOVABLE [jaewon31.kim@samsung.com: remove redundant code for high-order] Link: http://lkml.kernel.org/r/20200623035242.27232-1-jaewon31.kim@samsung.com Reported-by: Yong-Taek Lee <ytk.lee@samsung.com> Suggested-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Yong-Taek Lee <ytk.lee@samsung.com> Cc: Michal Hocko <mhocko@kernel.org> Link: http://lkml.kernel.org/r/20200619235958.11283-1-jaewon31.kim@samsung.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm, page_alloc: use unlikely() in task_capc()Vlastimil Babka1-3/+2
Hugh noted that task_capc() could use unlikely(), as most of the time there is no capture in progress and we are in page freeing hot path. Indeed adding unlikely() produces assembly that better matches the assumption and moves all the tests away from the hot path. I have also noticed that we don't need to test for cc->direct_compaction as the only place we set current->task_capture is compact_zone_order() which also always sets cc->direct_compaction true. Suggested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Hugh Dickins <hughd@googlecom> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Alex Shi <alex.shi@linux.alibaba.com> Cc: Li Wang <liwang@redhat.com> Link: http://lkml.kernel.org/r/4a24f7af-3aa5-6e80-4ae6-8f253b562039@suse.cz Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07mm/sparse: cleanup the code surrounding memory_present()Mike Rapoport1-16/+0
After removal of CONFIG_HAVE_MEMBLOCK_NODE_MAP we have two equivalent functions that call memory_present() for each region in memblock.memory: sparse_memory_present_with_active_regions() and membocks_present(). Moreover, all architectures have a call to either of these functions preceding the call to sparse_init() and in the most cases they are called one after the other. Mark the regions from memblock.memory as present during sparce_init() by making sparse_init() call memblocks_present(), make memblocks_present() and memory_present() functions static and remove redundant sparse_memory_present_with_active_regions() function. Also remove no longer required HAVE_MEMORY_PRESENT configuration option. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20200712083130.22919-1-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>