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2016-12-12mm/mempolicy.c: forbid static or relative flags for local NUMA modePiotr Kwapulinski
The MPOL_F_STATIC_NODES and MPOL_F_RELATIVE_NODES flags are irrelevant when setting them for MPOL_LOCAL NUMA memory policy via set_mempolicy or mbind. Return the "invalid argument" from set_mempolicy and mbind whenever any of these flags is passed along with MPOL_LOCAL. It is consistent with MPOL_PREFERRED passed with empty nodemask. It slightly shortens the execution time in paths where these flags are used e.g. when trying to rebind the NUMA nodes for changes in cgroups cpuset mems (mpol_rebind_preferred()) or when just printing the mempolicy structure (/proc/PID/numa_maps). Isolated tests done. Link: http://lkml.kernel.org/r/20161027163037.4089-1-kwapulinski.piotr@gmail.com Signed-off-by: Piotr Kwapulinski <kwapulinski.piotr@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@suse.com> Cc: Liang Chen <liangchen.linux@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: fix up get_user_pages* commentsLorenzo Stoakes
In the previous round of get_user_pages* changes comments attached to __get_user_pages_unlocked() and get_user_pages_unlocked() were rendered incorrect, this patch corrects them. In addition the get_user_pages_unlocked() comment seems to have already been outdated as it referred to tsk, mm parameters which were removed in c12d2da5 ("mm/gup: Remove the macro overload API migration helpers from the get_user*() APIs"), this patch fixes this also. Link: http://lkml.kernel.org/r/20161025233435.5338-1-lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: remove the page size change check in tlb_remove_pageAneesh Kumar K.V
Now that we check for page size change early in the loop, we can partially revert e9d55e157034a ("mm: change the interface for __tlb_remove_page"). This simplies the code much, by removing the need to track the last address with which we adjusted the range. We also go back to the older way of filling the mmu_gather array, ie, we add an entry and then check whether the gather batch is full. Link: http://lkml.kernel.org/r/20161026084839.27299-6-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: add tlb_remove_check_page_size_change to track page size changeAneesh Kumar K.V
With commit e77b0852b551 ("mm/mmu_gather: track page size with mmu gather and force flush if page size change") we added the ability to force a tlb flush when the page size change in a mmu_gather loop. We did that by checking for a page size change every time we added a page to mmu_gather for lazy flush/remove. We can improve that by moving the page size change check early and not doing it every time we add a page. This also helps us to do tlb flush when invalidating a range covering dax mapping. Wrt dax mapping we don't have a backing struct page and hence we don't call tlb_remove_page, which earlier forced the tlb flush on page size change. Moving the page size change check earlier means we will do the same even for dax mapping. We also avoid doing this check on architecture other than powerpc. In a later patch we will remove page size check from tlb_remove_page(). Link: http://lkml.kernel.org/r/20161026084839.27299-5-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/hugetlb: add tlb_remove_hugetlb_entry for handling hugetlb pagesAneesh Kumar K.V
This add tlb_remove_hugetlb_entry similar to tlb_remove_pmd_tlb_entry. Link: http://lkml.kernel.org/r/20161026084839.27299-4-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: update mmu_gather range correctlyAneesh Kumar K.V
We use __tlb_adjust_range to update range convered by mmu_gather struct. We later use the 'start' and 'end' to do a mmu_notifier_invalidate_range in tlb_flush_mmu_tlbonly(). Update the 'end' correctly in __tlb_adjust_range so that we call mmu_notifier_invalidate_range with the correct range values. Wrt tlbflush, this should not have any impact, because a flush with correct start address will flush tlb mapping for the range. Also add comment w.r.t updating the range when we free pagetable pages. For now we don't support a range based page table cache flush. Link: http://lkml.kernel.org/r/20161026084839.27299-3-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: use the correct page size when removing the pageAneesh Kumar K.V
We are removing a pmd hugepage here. Use the correct page size. Link: http://lkml.kernel.org/r/20161026084839.27299-2-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12shmem: avoid maybe-uninitialized warningArnd Bergmann
After enabling -Wmaybe-uninitialized warnings, we get a false-postive warning for shmem: mm/shmem.c: In function `shmem_getpage_gfp': include/linux/spinlock.h:332:21: error: `info' may be used uninitialized in this function [-Werror=maybe-uninitialized] This can be easily avoided, since the correct 'info' pointer is known at the time we first enter the function, so we can simply move the initialization up. Moving it before the first label avoids the warning and lets us remove two later initializations. Note that the function is so hard to read that it not only confuses the compiler, but also most readers and without this patch it could\ easily break if one of the 'goto's changed. Link: https://www.spinics.net/lists/kernel/msg2368133.html Link: http://lkml.kernel.org/r/20161024205725.786455-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm, compaction: fix NR_ISOLATED_* stats for pfn based migrationMing Ling
Since commit bda807d44454 ("mm: migrate: support non-lru movable page migration") isolate_migratepages_block) can isolate !PageLRU pages which would acct_isolated account as NR_ISOLATED_*. Accounting these non-lru pages NR_ISOLATED_{ANON,FILE} doesn't make any sense and it can misguide heuristics based on those counters such as pgdat_reclaimable_pages resp. too_many_isolated which would lead to unexpected stalls during the direct reclaim without any good reason. Note that __alloc_contig_migrate_range can isolate a lot of pages at once. On mobile devices such as 512M ram android Phone, it may use a big zram swap. In some cases zram(zsmalloc) uses too many non-lru but migratedable pages, such as: MemTotal: 468148 kB Normal free:5620kB Free swap:4736kB Total swap:409596kB ZRAM: 164616kB(zsmalloc non-lru pages) active_anon:60700kB inactive_anon:60744kB active_file:34420kB inactive_file:37532kB Fix this by only accounting lru pages to NR_ISOLATED_* in isolate_migratepages_block right after they were isolated and we still know they were on LRU. Drop acct_isolated because it is called after the fact and we've lost that information. Batching per-cpu counter doesn't make much improvement anyway. Also make sure that we uncharge only LRU pages when putting them back on the LRU in putback_movable_pages resp. when unmap_and_move migrates the page. [mhocko@suse.com: replace acct_isolated() with direct counting] Fixes: bda807d44454 ("mm: migrate: support non-lru movable page migration") Link: http://lkml.kernel.org/r/20161019080240.9682-1-mhocko@kernel.org Signed-off-by: Ming Ling <ming.ling@spreadtrum.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm, mempolicy: clean up __GFP_THISNODE confusion in policy_zonelistMichal Hocko
__GFP_THISNODE is documented to enforce the allocation to be satisified from the requested node with no fallbacks or placement policy enforcements. policy_zonelist seemingly breaks this semantic if the current policy is MPOL_MBIND and instead of taking the node it will fallback to the first node in the mask if the requested one is not in the mask. This is confusing to say the least because it fact we shouldn't ever go that path. First tasks shouldn't be scheduled on CPUs with nodes outside of their mempolicy binding. And secondly policy_zonelist is called only from 3 places: - huge_zonelist - never should do __GFP_THISNODE when going this path - alloc_pages_vma - which shouldn't depend on __GFP_THISNODE either - alloc_pages_current - which uses default_policy id __GFP_THISNODE is used So we shouldn't even need to care about this possibility and can drop the confusing code. Let's keep a WARN_ON_ONCE in place to catch potential users and fix them up properly (aka use a different allocation function which ignores mempolicy). [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20161013125958.32155-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm, thp: avoid unlikely branches for split_huge_pmdDavid Rientjes
While doing MADV_DONTNEED on a large area of thp memory, I noticed we encountered many unlikely() branches in profiles for each backing hugepage. This is because zap_pmd_range() would call split_huge_pmd(), which rechecked the conditions that were already validated, but as part of an unlikely() branch. Avoid the unlikely() branch when in a context where pmd is known to be good for __split_huge_pmd() directly. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1610181600300.84525@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/vmalloc.c: simplify /proc/vmallocinfo implementationzijun_hu
Many seq_file helpers exist for simplifying implementation of virtual files especially, for /proc nodes. however, the helpers for iteration over list_head are available but aren't adopted to implement /proc/vmallocinfo currently. Simplify /proc/vmallocinfo implementation by using existing seq_file helpers. Link: http://lkml.kernel.org/r/57FDF2E5.1000201@zoho.com Signed-off-by: zijun_hu <zijun_hu@htc.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: make unreserve highatomic functions reliableMinchan Kim
Currently, unreserve_highatomic_pageblock bails out if it found highatomic pageblock regardless of really moving free pages from the one so that it could mitigate unreserve logic's goal which saves OOM of a process. This patch makes unreserve functions bail out only if it moves some pages out of !highatomic free list to avoid such false positive. Another potential problem is that by race between page freeing and reserve highatomic function, pages could be in highatomic free list even though the pageblock is !high atomic migratetype. In that case, unreserve_highatomic_pageblock can be void if count of highatomic reserve is less than pageblock_nr_pages. We could solve it simply via draining all of reserved pages before the OOM. It would have a safeguard role to exhuast reserved pages before converging to OOM. Link: http://lkml.kernel.org/r/1476259429-18279-5-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: try to exhaust highatomic reserve before the OOMMinchan Kim
I got OOM report from production team with v4.4 kernel. It had enough free memory but failed to allocate GFP_KERNEL order-0 page and finally encountered OOM kill. It occured during QA process which launches several apps, switching and so on. It happned rarely. IOW, In normal situation, it was not a problem but if we are unluck so that several apps uses peak memory at the same time, it can happen. If we manage to pass the phase, the system can go working well. I could reproduce it with my test(memory spike easily. Look at below. The reason is free pages(19M) of DMA32 zone are reserved for HIGHORDERATOMIC and doesn't unreserved before the OOM. balloon invoked oom-killer: gfp_mask=0x24280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), order=0, oom_score_adj=0 balloon cpuset=/ mems_allowed=0 CPU: 1 PID: 8473 Comm: balloon Tainted: G W OE 4.8.0-rc7-00219-g3f74c9559583-dirty #3161 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: dump_stack+0x63/0x90 dump_header+0x5c/0x1ce oom_kill_process+0x22e/0x400 out_of_memory+0x1ac/0x210 __alloc_pages_nodemask+0x101e/0x1040 handle_mm_fault+0xa0a/0xbf0 __do_page_fault+0x1dd/0x4d0 trace_do_page_fault+0x43/0x130 do_async_page_fault+0x1a/0xa0 async_page_fault+0x28/0x30 Mem-Info: active_anon:383949 inactive_anon:106724 isolated_anon:0 active_file:15 inactive_file:44 isolated_file:0 unevictable:0 dirty:0 writeback:24 unstable:0 slab_reclaimable:2483 slab_unreclaimable:3326 mapped:0 shmem:0 pagetables:1906 bounce:0 free:6898 free_pcp:291 free_cma:0 Node 0 active_anon:1535796kB inactive_anon:426896kB active_file:60kB inactive_file:176kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:96kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1418 all_unreclaimable? no DMA free:8188kB min:44kB low:56kB high:68kB active_anon:7648kB inactive_anon:0kB active_file:0kB inactive_file:4kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:20kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 1952 1952 1952 DMA32 free:19404kB min:5628kB low:7624kB high:9620kB active_anon:1528148kB inactive_anon:426896kB active_file:60kB inactive_file:420kB unevictable:0kB writepending:96kB present:2080640kB managed:2030092kB mlocked:0kB slab_reclaimable:9932kB slab_unreclaimable:13284kB kernel_stack:2496kB pagetables:7624kB bounce:0kB free_pcp:900kB local_pcp:112kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 2*4096kB (H) = 8192kB DMA32: 7*4kB (H) 8*8kB (H) 30*16kB (H) 31*32kB (H) 14*64kB (H) 9*128kB (H) 2*256kB (H) 2*512kB (H) 4*1024kB (H) 5*2048kB (H) 0*4096kB = 19484kB 51131 total pagecache pages 50795 pages in swap cache Swap cache stats: add 3532405601, delete 3532354806, find 124289150/1822712228 Free swap = 8kB Total swap = 255996kB 524158 pages RAM 0 pages HighMem/MovableOnly 12658 pages reserved 0 pages cma reserved 0 pages hwpoisoned Another example exceeded the limit by the race is in:imklog: page allocation failure: order:0, mode:0x2280020(GFP_ATOMIC|__GFP_NOTRACK) CPU: 0 PID: 476 Comm: in:imklog Tainted: G E 4.8.0-rc7-00217-g266ef83c51e5-dirty #3135 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: dump_stack+0x63/0x90 warn_alloc_failed+0xdb/0x130 __alloc_pages_nodemask+0x4d6/0xdb0 new_slab+0x339/0x490 ___slab_alloc.constprop.74+0x367/0x480 __slab_alloc.constprop.73+0x20/0x40 __kmalloc+0x1a4/0x1e0 alloc_indirect.isra.14+0x1d/0x50 virtqueue_add_sgs+0x1c4/0x470 __virtblk_add_req+0xae/0x1f0 virtio_queue_rq+0x12d/0x290 __blk_mq_run_hw_queue+0x239/0x370 blk_mq_run_hw_queue+0x8f/0xb0 blk_mq_insert_requests+0x18c/0x1a0 blk_mq_flush_plug_list+0x125/0x140 blk_flush_plug_list+0xc7/0x220 blk_finish_plug+0x2c/0x40 __do_page_cache_readahead+0x196/0x230 filemap_fault+0x448/0x4f0 ext4_filemap_fault+0x36/0x50 __do_fault+0x75/0x140 handle_mm_fault+0x84d/0xbe0 __do_page_fault+0x1dd/0x4d0 trace_do_page_fault+0x43/0x130 do_async_page_fault+0x1a/0xa0 async_page_fault+0x28/0x30 Mem-Info: active_anon:363826 inactive_anon:121283 isolated_anon:32 active_file:65 inactive_file:152 isolated_file:0 unevictable:0 dirty:0 writeback:46 unstable:0 slab_reclaimable:2778 slab_unreclaimable:3070 mapped:112 shmem:0 pagetables:1822 bounce:0 free:9469 free_pcp:231 free_cma:0 Node 0 active_anon:1455304kB inactive_anon:485132kB active_file:260kB inactive_file:608kB unevictable:0kB isolated(anon):128kB isolated(file):0kB mapped:448kB dirty:0kB writeback:184kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:13641 all_unreclaimable? no DMA free:7748kB min:44kB low:56kB high:68kB active_anon:7944kB inactive_anon:104kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:108kB kernel_stack:0kB pagetables:4kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 1952 1952 1952 DMA32 free:30128kB min:5628kB low:7624kB high:9620kB active_anon:1447360kB inactive_anon:485028kB active_file:260kB inactive_file:608kB unevictable:0kB writepending:184kB present:2080640kB managed:2030132kB mlocked:0kB slab_reclaimable:11112kB slab_unreclaimable:12172kB kernel_stack:2400kB pagetables:7284kB bounce:0kB free_pcp:924kB local_pcp:72kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 DMA: 7*4kB (UE) 3*8kB (UH) 1*16kB (M) 0*32kB 2*64kB (U) 1*128kB (M) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (U) 1*4096kB (H) = 7748kB DMA32: 10*4kB (H) 3*8kB (H) 47*16kB (H) 38*32kB (H) 5*64kB (H) 1*128kB (H) 2*256kB (H) 3*512kB (H) 3*1024kB (H) 3*2048kB (H) 4*4096kB (H) = 30128kB 2775 total pagecache pages 2536 pages in swap cache Swap cache stats: add 206786828, delete 206784292, find 7323106/106686077 Free swap = 108744kB Total swap = 255996kB 524158 pages RAM 0 pages HighMem/MovableOnly 12648 pages reserved 0 pages cma reserved 0 pages hwpoisoned It's weird to show that zone has enough free memory above min watermark but OOMed with 4K GFP_KERNEL allocation due to reserved highatomic pages. As last resort, try to unreserve highatomic pages again and if it has moved pages to non-highatmoc free list, retry reclaim once more. Link: http://lkml.kernel.org/r/1476259429-18279-4-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: prevent double decrease of nr_reserved_highatomicMinchan Kim
There is race between page freeing and unreserved highatomic. CPU 0 CPU 1 free_hot_cold_page mt = get_pfnblock_migratetype set_pcppage_migratetype(page, mt) unreserve_highatomic_pageblock spin_lock_irqsave(&zone->lock) move_freepages_block set_pageblock_migratetype(page) spin_unlock_irqrestore(&zone->lock) free_pcppages_bulk __free_one_page(mt) <- mt is stale By above race, a page on CPU 0 could go non-highorderatomic free list since the pageblock's type is changed. By that, unreserve logic of highorderatomic can decrease reserved count on a same pageblock severak times and then it will make mismatch between nr_reserved_highatomic and the number of reserved pageblock. So, this patch verifies whether the pageblock is highatomic or not and decrease the count only if the pageblock is highatomic. Link: http://lkml.kernel.org/r/1476259429-18279-3-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: don't steal highatomic pageblockMinchan Kim
Patch series "use up highorder free pages before OOM", v3. I got OOM report from production team with v4.4 kernel. It had enough free memory but failed to allocate GFP_KERNEL order-0 page and finally encountered OOM kill. It occured during QA process which launches several apps, switching and so on. It happned rarely. IOW, In normal situation, it was not a problem but if we are unluck so that several apps uses peak memory at the same time, it can happen. If we manage to pass the phase, the system can go working well. I could reproduce it with my test(memory spike easily. Look at below. The reason is free pages(19M) of DMA32 zone are reserved for HIGHORDERATOMIC and doesn't unreserved before the OOM. balloon invoked oom-killer: gfp_mask=0x24280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), order=0, oom_score_adj=0 balloon cpuset=/ mems_allowed=0 CPU: 1 PID: 8473 Comm: balloon Tainted: G W OE 4.8.0-rc7-00219-g3f74c9559583-dirty #3161 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: dump_stack+0x63/0x90 dump_header+0x5c/0x1ce oom_kill_process+0x22e/0x400 out_of_memory+0x1ac/0x210 __alloc_pages_nodemask+0x101e/0x1040 handle_mm_fault+0xa0a/0xbf0 __do_page_fault+0x1dd/0x4d0 trace_do_page_fault+0x43/0x130 do_async_page_fault+0x1a/0xa0 async_page_fault+0x28/0x30 Mem-Info: active_anon:383949 inactive_anon:106724 isolated_anon:0 active_file:15 inactive_file:44 isolated_file:0 unevictable:0 dirty:0 writeback:24 unstable:0 slab_reclaimable:2483 slab_unreclaimable:3326 mapped:0 shmem:0 pagetables:1906 bounce:0 free:6898 free_pcp:291 free_cma:0 Node 0 active_anon:1535796kB inactive_anon:426896kB active_file:60kB inactive_file:176kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:0kB dirty:0kB writeback:96kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:1418 all_unreclaimable? no DMA free:8188kB min:44kB low:56kB high:68kB active_anon:7648kB inactive_anon:0kB active_file:0kB inactive_file:4kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:20kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 1952 1952 1952 DMA32 free:19404kB min:5628kB low:7624kB high:9620kB active_anon:1528148kB inactive_anon:426896kB active_file:60kB inactive_file:420kB unevictable:0kB writepending:96kB present:2080640kB managed:2030092kB mlocked:0kB slab_reclaimable:9932kB slab_unreclaimable:13284kB kernel_stack:2496kB pagetables:7624kB bounce:0kB free_pcp:900kB local_pcp:112kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 2*4096kB (H) = 8192kB DMA32: 7*4kB (H) 8*8kB (H) 30*16kB (H) 31*32kB (H) 14*64kB (H) 9*128kB (H) 2*256kB (H) 2*512kB (H) 4*1024kB (H) 5*2048kB (H) 0*4096kB = 19484kB 51131 total pagecache pages 50795 pages in swap cache Swap cache stats: add 3532405601, delete 3532354806, find 124289150/1822712228 Free swap = 8kB Total swap = 255996kB 524158 pages RAM 0 pages HighMem/MovableOnly 12658 pages reserved 0 pages cma reserved 0 pages hwpoisoned Another example exceeded the limit by the race is in:imklog: page allocation failure: order:0, mode:0x2280020(GFP_ATOMIC|__GFP_NOTRACK) CPU: 0 PID: 476 Comm: in:imklog Tainted: G E 4.8.0-rc7-00217-g266ef83c51e5-dirty #3135 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 Call Trace: dump_stack+0x63/0x90 warn_alloc_failed+0xdb/0x130 __alloc_pages_nodemask+0x4d6/0xdb0 new_slab+0x339/0x490 ___slab_alloc.constprop.74+0x367/0x480 __slab_alloc.constprop.73+0x20/0x40 __kmalloc+0x1a4/0x1e0 alloc_indirect.isra.14+0x1d/0x50 virtqueue_add_sgs+0x1c4/0x470 __virtblk_add_req+0xae/0x1f0 virtio_queue_rq+0x12d/0x290 __blk_mq_run_hw_queue+0x239/0x370 blk_mq_run_hw_queue+0x8f/0xb0 blk_mq_insert_requests+0x18c/0x1a0 blk_mq_flush_plug_list+0x125/0x140 blk_flush_plug_list+0xc7/0x220 blk_finish_plug+0x2c/0x40 __do_page_cache_readahead+0x196/0x230 filemap_fault+0x448/0x4f0 ext4_filemap_fault+0x36/0x50 __do_fault+0x75/0x140 handle_mm_fault+0x84d/0xbe0 __do_page_fault+0x1dd/0x4d0 trace_do_page_fault+0x43/0x130 do_async_page_fault+0x1a/0xa0 async_page_fault+0x28/0x30 Mem-Info: active_anon:363826 inactive_anon:121283 isolated_anon:32 active_file:65 inactive_file:152 isolated_file:0 unevictable:0 dirty:0 writeback:46 unstable:0 slab_reclaimable:2778 slab_unreclaimable:3070 mapped:112 shmem:0 pagetables:1822 bounce:0 free:9469 free_pcp:231 free_cma:0 Node 0 active_anon:1455304kB inactive_anon:485132kB active_file:260kB inactive_file:608kB unevictable:0kB isolated(anon):128kB isolated(file):0kB mapped:448kB dirty:0kB writeback:184kB shmem:0kB writeback_tmp:0kB unstable:0kB pages_scanned:13641 all_unreclaimable? no DMA free:7748kB min:44kB low:56kB high:68kB active_anon:7944kB inactive_anon:104kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15908kB mlocked:0kB slab_reclaimable:0kB slab_unreclaimable:108kB kernel_stack:0kB pagetables:4kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB lowmem_reserve[]: 0 1952 1952 1952 DMA32 free:30128kB min:5628kB low:7624kB high:9620kB active_anon:1447360kB inactive_anon:485028kB active_file:260kB inactive_file:608kB unevictable:0kB writepending:184kB present:2080640kB managed:2030132kB mlocked:0kB slab_reclaimable:11112kB slab_unreclaimable:12172kB kernel_stack:2400kB pagetables:7284kB bounce:0kB free_pcp:924kB local_pcp:72kB free_cma:0kB lowmem_reserve[]: 0 0 0 0 DMA: 7*4kB (UE) 3*8kB (UH) 1*16kB (M) 0*32kB 2*64kB (U) 1*128kB (M) 1*256kB (U) 0*512kB 1*1024kB (U) 1*2048kB (U) 1*4096kB (H) = 7748kB DMA32: 10*4kB (H) 3*8kB (H) 47*16kB (H) 38*32kB (H) 5*64kB (H) 1*128kB (H) 2*256kB (H) 3*512kB (H) 3*1024kB (H) 3*2048kB (H) 4*4096kB (H) = 30128kB 2775 total pagecache pages 2536 pages in swap cache Swap cache stats: add 206786828, delete 206784292, find 7323106/106686077 Free swap = 108744kB Total swap = 255996kB 524158 pages RAM 0 pages HighMem/MovableOnly 12648 pages reserved 0 pages cma reserved 0 pages hwpoisoned During the investigation, I found some problems with highatomic so this patch aims to solve the problems and the final goal is to unreserve every highatomic free pages before the OOM kill. This patch (of 4): In page freeing path, migratetype is racy so that a highorderatomic page could free into non-highorderatomic free list. If that page is allocated, VM can change the pageblock from higorderatomic to something. In that case, highatomic pageblock accounting is broken so it doesn't work(e.g., VM cannot reserve highorderatomic pageblocks any more although it doesn't reach 1% limit). So, this patch prohibits the changing from highatomic to other type. It's no problem because MIGRATE_HIGHATOMIC is not listed in fallback array so stealing will only happen due to unexpected races which is really rare. Also, such prohibiting keeps highatomic pageblock more longer so it would be better for highorderatomic page allocation. Link: http://lkml.kernel.org/r/1476259429-18279-2-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Sangseok Lee <sangseok.lee@lge.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12kmemleak: fix reference to DocumentationAndreas Platschek
Documentation/kmemleak.txt was moved to Documentation/dev-tools/kmemleak.rst, this fixes the reference to the new location. Link: http://lkml.kernel.org/r/1476544946-18804-1-git-send-email-andreas.platschek@opentech.at Signed-off-by: Andreas Platschek <andreas.platschek@opentech.at> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/hugetlb.c: use huge_pte_lock instead of opencoding the lockAneesh Kumar K.V
No functional change by this patch. Link: http://lkml.kernel.org/r/20161018090234.22574-1-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/hugetlb.c: use the right pte val for compare in hugetlb_cowAneesh Kumar K.V
We cannot use the pte value used in set_pte_at for pte_same comparison, because archs like ppc64, filter/add new pte flag in set_pte_at. Instead fetch the pte value inside hugetlb_cow. We are comparing pte value to make sure the pte didn't change since we dropped the page table lock. hugetlb_cow get called with page table lock held, and we can take a copy of the pte value before we drop the page table lock. With hugetlbfs, we optimize the MAP_PRIVATE write fault path with no previous mapping (huge_pte_none entries), by forcing a cow in the fault path. This avoid take an addition fault to covert a read-only mapping to read/write. Here we were comparing a recently instantiated pte (via set_pte_at) to the pte values from linux page table. As explained above on ppc64 such pte_same check returned wrong result, resulting in us taking an additional fault on ppc64. Fixes: 6a119eae942c ("powerpc/mm: Add a _PAGE_PTE bit") Link: http://lkml.kernel.org/r/20161018154245.18023-1-aneesh.kumar@linux.vnet.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reported-by: Jan Stancek <jstancek@redhat.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Scott Wood <scottwood@freescale.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/gup.c: make unnecessarily global vma_permits_fault() staticTobias Klauser
Make vma_permits_fault() static as it is only used in mm/gup.c This fixes a sparse warning. Link: http://lkml.kernel.org/r/20161017122353.31598-1-tklauser@distanz.ch Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/vmscan.c: set correct defer count for shrinkerShaohua Li
Our system uses significantly more slab memory with memcg enabled with the latest kernel. With 3.10 kernel, slab uses 2G memory, while with 4.6 kernel, 6G memory is used. The shrinker has problem. Let's see we have two memcg for one shrinker. In do_shrink_slab: 1. Check cg1. nr_deferred = 0, assume total_scan = 700. batch size is 1024, then no memory is freed. nr_deferred = 700 2. Check cg2. nr_deferred = 700. Assume freeable = 20, then total_scan = 10 or 40. Let's assume it's 10. No memory is freed. nr_deferred = 10. The deferred share of cg1 is lost in this case. kswapd will free no memory even run above steps again and again. The fix makes sure one memcg's deferred share isn't lost. Link: http://lkml.kernel.org/r/2414be961b5d25892060315fbb56bb19d81d0c07.1476227351.git.shli@fb.com Signed-off-by: Shaohua Li <shli@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: <stable@vger.kernel.org> [4.0+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/mprotect.c: don't touch single threaded PTEs which are on the right nodeAndi Kleen
We had some problems with pages getting unmapped in single threaded affinitized processes. It was tracked down to NUMA scanning. In this case it doesn't make any sense to unmap pages if the process is single threaded and the page is already on the node the process is running on. Add a check for this case into the numa protection code, and skip unmapping if true. In theory the process could be migrated later, but we will eventually rescan and unmap and migrate then. In theory this could be made more fancy: remembering this state per process or even whole mm. However that would need extra tracking and be more complicated, and the simple check seems to work fine so far. [ak@linux.intel.com: v3: Minor updates from Mel. Change code layout] Link: http://lkml.kernel.org/r/1476382117-5440-1-git-send-email-andi@firstfloor.org Link: http://lkml.kernel.org/r/1476288949-20970-1-git-send-email-andi@firstfloor.org Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm, slab: maintain total slab count instead of active countDavid Rientjes
Rather than tracking the number of active slabs for each node, track the total number of slabs. This is a minor improvement that avoids active slab tracking when a slab goes from free to partial or partial to free. For slab debugging, this also removes an explicit free count since it can easily be inferred by the difference in number of total objects and number of active objects. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1612042020110.115755@chino.kir.corp.google.com Signed-off-by: David Rientjes <rientjes@google.com> Suggested-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Greg Thelen <gthelen@google.com> Cc: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm, slab: faster active and free statsGreg Thelen
Reading /proc/slabinfo or monitoring slabtop(1) can become very expensive if there are many slab caches and if there are very lengthy per-node partial and/or free lists. Commit 07a63c41fa1f ("mm/slab: improve performance of gathering slabinfo stats") addressed the per-node full lists which showed a significant improvement when no objects were freed. This patch has the same motivation and optimizes the remainder of the usecases where there are very lengthy partial and free lists. This patch maintains per-node active_slabs (full and partial) and free_slabs rather than iterating the lists at runtime when reading /proc/slabinfo. When allocating 100GB of slab from a test cache where every slab page is on the partial list, reading /proc/slabinfo (includes all other slab caches on the system) takes ~247ms on average with 48 samples. As a result of this patch, the same read takes ~0.856ms on average. [rientjes@google.com: changelog] Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1611081505240.13403@chino.kir.corp.google.com Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm/slab_common.c: check kmem_create_cache flags are commonThomas Garnier
Verify that kmem_create_cache flags are not allocator specific. It is done before removing flags that are not available with the current configuration. The current kmem_cache_create removes incorrect flags but do not validate the callers are using them right. This change will ensure that callers are not trying to create caches with flags that won't be used because allocator specific. Link: http://lkml.kernel.org/r/1478553075-120242-2-git-send-email-thgarnie@google.com Signed-off-by: Thomas Garnier <thgarnie@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12slub: avoid false-postive warningArnd Bergmann
The slub allocator gives us some incorrect warnings when CONFIG_PROFILE_ANNOTATED_BRANCHES is set, as the unlikely() macro prevents it from seeing that the return code matches what it was before: mm/slub.c: In function `kmem_cache_free_bulk': mm/slub.c:262:23: error: `df.s' may be used uninitialized in this function [-Werror=maybe-uninitialized] mm/slub.c:2943:3: error: `df.cnt' may be used uninitialized in this function [-Werror=maybe-uninitialized] mm/slub.c:2933:4470: error: `df.freelist' may be used uninitialized in this function [-Werror=maybe-uninitialized] mm/slub.c:2943:3: error: `df.tail' may be used uninitialized in this function [-Werror=maybe-uninitialized] I have not been able to come up with a perfect way for dealing with this, the three options I see are: - add a bogus initialization, which would increase the runtime overhead - replace unlikely() with unlikely_notrace() - remove the unlikely() annotation completely I checked the object code for a typical x86 configuration and the last two cases produce the same result, so I went for the last one, which is the simplest. Link: http://lkml.kernel.org/r/20161024155704.3114445-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12slub: move synchronize_sched out of slab_mutex on shrinkVladimir Davydov
synchronize_sched() is a heavy operation and calling it per each cache owned by a memory cgroup being destroyed may take quite some time. What is worse, it's currently called under the slab_mutex, stalling all works doing cache creation/destruction. Actually, there isn't much point in calling synchronize_sched() for each cache - it's enough to call it just once - after setting cpu_partial for all caches and before shrinking them. This way, we can also move it out of the slab_mutex, which we have to hold for iterating over the slab cache list. Link: https://bugzilla.kernel.org/show_bug.cgi?id=172991 Link: http://lkml.kernel.org/r/0a10d71ecae3db00fb4421bcd3f82bcc911f4be4.1475329751.git.vdavydov.dev@gmail.com Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reported-by: Doug Smythies <dsmythies@telus.net> Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12mm: memcontrol: use special workqueue for creating per-memcg cachesVladimir Davydov
Creating a lot of cgroups at the same time might stall all worker threads with kmem cache creation works, because kmem cache creation is done with the slab_mutex held. The problem was amplified by commits 801faf0db894 ("mm/slab: lockless decision to grow cache") in case of SLAB and 81ae6d03952c ("mm/slub.c: replace kick_all_cpus_sync() with synchronize_sched() in kmem_cache_shrink()") in case of SLUB, which increased the maximal time the slab_mutex can be held. To prevent that from happening, let's use a special ordered single threaded workqueue for kmem cache creation. This shouldn't introduce any functional changes regarding how kmem caches are created, as the work function holds the global slab_mutex during its whole runtime anyway, making it impossible to run more than one work at a time. By using a single threaded workqueue, we just avoid creating a thread per each work. Ordering is required to avoid a situation when a cgroup's work is put off indefinitely because there are other cgroups to serve, in other words to guarantee fairness. Link: https://bugzilla.kernel.org/show_bug.cgi?id=172981 Link: http://lkml.kernel.org/r/20161004131417.GC1862@esperanza Signed-off-by: Vladimir Davydov <vdavydov.dev@gmail.com> Reported-by: Doug Smythies <dsmythies@telus.net> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2: replace CURRENT_TIME macroDeepa Dinamani
CURRENT_TIME is not y2038 safe. Use y2038 safe ktime_get_real_seconds() here for timestamps. struct heartbeat_block's hb_seq and deletetion time are already 64 bits wide and accommodate times beyond y2038. Also use y2038 safe ktime_get_real_ts64() for on disk inode timestamps. These are also wide enough to accommodate time64_t. Link: http://lkml.kernel.org/r/1475365298-29236-1-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2: use time64_t to represent orphan scan timesDeepa Dinamani
struct timespec is not y2038 safe. Use time64_t which is y2038 safe to represent orphan scan times. time64_t is sufficient here as only the seconds delta times are relevant. Also use appropriate time functions that return time in time64_t format. Time functions now return monotonic time instead of real time as only delta scan times are relevant and these values are not persistent across reboots. The format string for the debug print is still using long as this is only the time elapsed since the last scan and long is sufficient to represent this value. Link: http://lkml.kernel.org/r/1475365138-20567-1-git-send-email-deepa.kernel@gmail.com Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2: fix double put of recount tree in ocfs2_lock_refcount_tree()Ashish Samant
In ocfs2_lock_refcount_tree, if ocfs2_read_refcount_block() returns an error, we do ocfs2_refcount_tree_put twice (once in ocfs2_unlock_refcount_tree and once outside it), thereby reducing the refcount of the refcount tree twice, but we dont delete the tree in this case. This will make refcnt of the tree = 0 and the ocfs2_refcount_tree_put will eventually call ocfs2_mark_lockres_freeing, setting OCFS2_LOCK_FREEING for the refcount_tree->rf_lockres. The error returned by ocfs2_read_refcount_block is propagated all the way back and for next iteration of write, ocfs2_lock_refcount_tree gets the same tree back from ocfs2_get_refcount_tree because we havent deleted the tree. Now we have the same tree, but OCFS2_LOCK_FREEING is set for rf_lockres and eventually, when _ocfs2_lock_refcount_tree is called in this iteration, BUG_ON( __ocfs2_cluster_lock:1395 ERROR: Cluster lock called on freeing lockres T00000000000000000386019775b08d! flags 0x81) is triggerred. Call stack: (loop16,11155,0):ocfs2_lock_refcount_tree:482 ERROR: status = -5 (loop16,11155,0):ocfs2_refcount_cow_hunk:3497 ERROR: status = -5 (loop16,11155,0):ocfs2_refcount_cow:3560 ERROR: status = -5 (loop16,11155,0):ocfs2_prepare_inode_for_refcount:2111 ERROR: status = -5 (loop16,11155,0):ocfs2_prepare_inode_for_write:2190 ERROR: status = -5 (loop16,11155,0):ocfs2_file_write_iter:2331 ERROR: status = -5 (loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: bug expression: lockres->l_flags & OCFS2_LOCK_FREEING (loop16,11155,0):__ocfs2_cluster_lock:1395 ERROR: Cluster lock called on freeing lockres T00000000000000000386019775b08d! flags 0x81 kernel BUG at fs/ocfs2/dlmglue.c:1395! invalid opcode: 0000 [#1] SMP CPU 0 Modules linked in: tun ocfs2 jbd2 xen_blkback xen_netback xen_gntdev .. sd_mod crc_t10dif ext3 jbd mbcache RIP: __ocfs2_cluster_lock+0x31c/0x740 [ocfs2] RSP: e02b:ffff88017c0138a0 EFLAGS: 00010086 Process loop16 (pid: 11155, threadinfo ffff88017c010000, task ffff8801b5374300) Call Trace: ocfs2_refcount_lock+0xae/0x130 [ocfs2] __ocfs2_lock_refcount_tree+0x29/0xe0 [ocfs2] ocfs2_lock_refcount_tree+0xdd/0x320 [ocfs2] ocfs2_refcount_cow_hunk+0x1cb/0x440 [ocfs2] ocfs2_refcount_cow+0xa9/0x1d0 [ocfs2] ocfs2_prepare_inode_for_refcount+0x115/0x200 [ocfs2] ocfs2_prepare_inode_for_write+0x33b/0x470 [ocfs2] ocfs2_file_write_iter+0x220/0x8c0 [ocfs2] aio_write_iter+0x2e/0x30 Fix this by avoiding the second call to ocfs2_refcount_tree_put() Link: http://lkml.kernel.org/r/1473984404-32011-1-git-send-email-ashish.samant@oracle.com Signed-off-by: Ashish Samant <ashish.samant@oracle.com> Reviewed-by: Eric Ren <zren@suse.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2: clean up unused 'page' parameter in ocfs2_write_end_nolock()piaojun
'page' parameter in ocfs2_write_end_nolock() is never used. Link: http://lkml.kernel.org/r/582FD91A.5000902@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2/dlm: clean up deadcode in dlm_master_request_handler()piaojun
When 'dispatch_assert' is set, 'response' must be DLM_MASTER_RESP_YES, and 'res' won't be null, so execution can't reach these two branch. Link: http://lkml.kernel.org/r/58174C91.3040004@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Joseph Qi Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2: delete redundant code and set the node bit into maybe_map directlyGuozhonghua
The variable `set_maybe' is redundant when the mle has been found in the map. So it is ok to set the node_idx into mle's maybe_map directly. Link: http://lkml.kernel.org/r/71604351584F6A4EBAE558C676F37CA4A3D490DD@H3CMLB12-EX.srv.huawei-3com.com Signed-off-by: Guozhonghua <guozhonghua@h3c.com> Reviewed-by: Mark Fasheh <mfasheh@versity.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12ocfs2/dlm: clean up useless BUG_ON default case in dlm_finalize_reco_handler()piaojun
The value of 'stage' must be between 1 and 2, so the switch can't reach the default case. Link: http://lkml.kernel.org/r/57FB5EB2.7050002@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12drivers/pcmcia/m32r_pcc.c: check return from add_pcc_socketSudip Mukherjee
If request_irq() fails it passes the error to the caller. The caller now checks it and jumps to the common error path on failure. Link: http://lkml.kernel.org/r/1474237304-897-3-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12drivers/pcmcia/m32r_pcc.c: use common error pathSudip Mukherjee
Use a common error path for the failure. Link: http://lkml.kernel.org/r/1474237304-897-2-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12drivers/pcmcia/m32r_pcc.c: check return from request_irqSudip Mukherjee
While building m32r allmodconfig we were getting warning: drivers/pcmcia/m32r_pcc.c:331:2: warning: ignoring return value of 'request_irq', declared with attribute warn_unused_result request_irq() can fail and we should always be checking the result from it. Check the result and return it to the caller. Link: http://lkml.kernel.org/r/1474237304-897-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12m32r: fix build warningSudip Mukherjee
While building m32r defconfig we got warnings: arch/m32r/platforms/m32700ut/setup.c:249:24: warning: 'm32700ut_lcdpld_irq_type' defined but not used [-Wunused-variable] m32700ut_lcdpld_irq_type is only used when CONFIG_USB is enabled. Modify the code to declare the related variables and functions only when CONFIG_USB is enabled. Link: http://lkml.kernel.org/r/1479244406-7507-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12m32r: add simple dmaSudip Mukherjee
Some builds of m32r were failing as it tried to build few drivers which needed dma but m32r is not having dma support. Objections were raised when it was tried to make those drivers depend on HAS_DMA. So the next best thing is to add dma support to m32r. dma_noop is a very simple dma with 1:1 memory mapping. Link: http://lkml.kernel.org/r/1475949198-31623-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12scripts/tags.sh: handle OMAP platforms properlySam Protsenko
When SUBARCH is "omap1" or "omap2", plat-omap/ directory must be indexed. Handle this special case properly. While at it, check if mach- directory exists at all. Link: http://lkml.kernel.org/r/20161202122148.15001-1-joe.skb7@gmail.com Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org> Cc: Michal Marek <mmarek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12scripts/bloat-o-meter: compile .NUMBER regexAlexey Dobriyan
Every often used regex is better be compiled in Python. Speedup is about ~9.8% (whee!) $ perf stat -r 16 taskset -c 15 ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux >/dev/null 7.091202853 seconds time elapsed ( +- 0.15% ) +re.compile 6.397564973 seconds time elapsed ( +- 0.34% ) Link: http://lkml.kernel.org/r/20161119004417.GB1200@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12scripts/bloat-o-meter: don't use readlines()Alexey Dobriyan
readlines() conses whole list before doing anything which is slower for big object files. Use per line iterator. Speed up is ~2% on "allyesconfig" type of kernel. $ perf stat -r 16 taskset -c 15 ./scripts/bloat-o-meter ../vmlinux-000 ../obj/vmlinux >/dev/null ... Before: 7.247708646 seconds time elapsed ( +- 0.28% ) After: 7.091202853 seconds time elapsed ( +- 0.15% ) Link: http://lkml.kernel.org/r/20161119004143.GA1200@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12prctl: remove one-shot limitation for changing exe linkStanislav Kinsburskiy
This limitation came with the reason to remove "another way for malicious code to obscure a compromised program and masquerade as a benign process" by allowing "security-concious program can use this prctl once during its early initialization to ensure the prctl cannot later be abused for this purpose": http://marc.info/?l=linux-kernel&m=133160684517468&w=2 This explanation doesn't look sufficient. The only thing "exe" link is indicating is the file, used to execve, which is basically nothing and not reliable immediately after process has returned from execve system call. Moreover, to use this feture, all the mappings to previous exe file have to be unmapped and all the new exe file permissions must be satisfied. Which means, that changing exe link is very similar to calling execve on the binary. The need to remove this limitations comes from migration of NFS mount point, which is not accessible during restore and replaced by other file system. Because of this exe link has to be changed twice. [akpm@linux-foundation.org: fix up comment] Link: http://lkml.kernel.org/r/20160927153755.9337.69650.stgit@localhost.localdomain Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: John Stultz <john.stultz@linaro.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12kthread: add __printf attributesNicolas Iooss
When commit fbae2d44aa1d ("kthread: add kthread_create_worker*()") introduced some kthread_create_...() functions which were taking printf-like parametter, it introduced __printf attributes to some functions (e.g. kthread_create_worker()). Nevertheless some new functions were forgotten (they have been detected thanks to -Wmissing-format-attribute warning flag). Add the missing __printf attributes to the newly-introduced functions in order to detect formatting issues at build-time with -Wformat flag. Link: http://lkml.kernel.org/r/20161126193543.22672-1-nicolas.iooss_linux@m4x.org Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12Merge branch 'ras-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 RAS updates from Ingo Molnar: "The main changes in this development cycle were: - more AMD northbridge support work, mostly in preparation for Fam17h CPUs (Yazen Ghannam, Borislav Petkov) - cleanups/refactorings and fixes (Borislav Petkov, Tony Luck, Yinghai Lu)" * 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Include the PPIN in MCE records when available x86/mce/AMD: Add system physical address translation for AMD Fam17h x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h x86/amd_nb: Add Fam17h Data Fabric as "Northbridge" x86/amd_nb: Make all exports EXPORT_SYMBOL_GPL x86/amd_nb: Make amd_northbridges internal to amd_nb.c x86/mce/AMD: Reset Threshold Limit after logging error x86/mce/AMD: Fix HWID_MCATYPE calculation by grouping arguments x86/MCE: Correct TSC timestamping of error records x86/RAS: Hide SMCA bank names x86/RAS: Rename smca_bank_names to smca_names x86/RAS: Simplify SMCA HWID descriptor struct x86/RAS: Simplify SMCA bank descriptor struct x86/MCE: Dump MCE to dmesg if no consumers x86/RAS: Add TSC timestamp to the injected MCE x86/MCE: Do not look at panic_on_oops in the severity grading
2016-12-12Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull hotplug API fix from Ingo Molnar: "Late breaking fix from the v4.9 cycle: fix a hotplug register/ unregister notifier API asymmetry bug that can cause kernel warnings (and worse) with certain Kconfig combinations" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hotplug: Make register and unregister notifier API symmetric
2016-12-12Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main scheduler changes in this cycle were: - support Intel Turbo Boost Max Technology 3.0 (TBM3) by introducig a notion of 'better cores', which the scheduler will prefer to schedule single threaded workloads on. (Tim Chen, Srinivas Pandruvada) - enhance the handling of asymmetric capacity CPUs further (Morten Rasmussen) - improve/fix load handling when moving tasks between task groups (Vincent Guittot) - simplify and clean up the cputime code (Stanislaw Gruszka) - improve mass fork()ed task spread a.k.a. hackbench speedup (Vincent Guittot) - make struct kthread kmalloc()ed and related fixes (Oleg Nesterov) - add uaccess atomicity debugging (when using access_ok() in the wrong context), under CONFIG_DEBUG_ATOMIC_SLEEP=y (Peter Zijlstra) - implement various fixes, cleanups and other enhancements (Daniel Bristot de Oliveira, Martin Schwidefsky, Rafael J. Wysocki)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) sched/core: Use load_avg for selecting idlest group sched/core: Fix find_idlest_group() for fork kthread: Don't abuse kthread_create_on_cpu() in __kthread_create_worker() kthread: Don't use to_live_kthread() in kthread_[un]park() kthread: Don't use to_live_kthread() in kthread_stop() Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function" kthread: Make struct kthread kmalloc'ed x86/uaccess, sched/preempt: Verify access_ok() context sched/x86: Make CONFIG_SCHED_MC_PRIO=y easier to enable sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO x86/sched: Use #include <linux/mutex.h> instead of #include <asm/mutex.h> cpufreq/intel_pstate: Use CPPC to get max performance acpi/bus: Set _OSC for diverse core support acpi/bus: Enable HWP CPPC objects x86/sched: Add SD_ASYM_PACKING flags to x86 ITMT CPU x86/sysctl: Add sysctl for ITMT scheduling feature x86: Enable Intel Turbo Boost Max Technology 3.0 x86/topology: Define x86's arch_update_cpu_topology sched: Extend scheduler's asym packing sched/fair: Clean up the tunable parameter definitions ...
2016-12-12Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "This update is pretty big and almost exclusively includes tooling changes, because v4.9's LTS status forced to completion most of the pending kernel side hardware enablement work and because we tried to freeze core perf work a bit to give a time window for the fuzzing efforts. The diff is large mostly due to the JSON hardware event tables added for Intel and Power8 CPUs. This was a popular feature request from people working close to hardware and from the HPC community. Tree size is big because this added the CPU event tables for over a decade of Intel CPUs. Future changes for a CPU vendor alrady support should be much smaller, as events for new models are added. The new events are listed in 'perf list', for the CPU model the tool is running on. If you find an interesting event it can be used as-is: $ perf stat -a -e l2_lines_out.pf_clean sleep 1 Performance counter stats for 'system wide': 7,860,403 l2_lines_out.pf_clean 1.000624918 seconds time elapsed The event lists can be searched the usual 'perf list' fashion for (case insensitive) substrings as well: $ perf list l2_lines_out List of pre-defined events (to be used in -e): cache: l2_lines_out.demand_clean [Clean L2 cache lines evicted by demand] l2_lines_out.demand_dirty [Dirty L2 cache lines evicted by demand] l2_lines_out.dirty_all [Dirty L2 cache lines filling the L2] l2_lines_out.pf_clean [Clean L2 cache lines evicted by L2 prefetch] l2_lines_out.pf_dirty [Dirty L2 cache lines evicted by L2 prefetch] etc. There's a few high level categories as well that can be listed: 'cache', 'floating point', 'frontend', 'memory', 'pipeline', 'virtual memory'. Existing generic events and workflows should work as-is. The only kernel side change is a late breaking fix for an older regression, related to Intel BTS, LBR and PT feature interaction. On the tooling side there are three new tools / major features: - The new 'perf c2c' tool provides means for Shared Data C2C/HITM analysis. This allows you to track down cacheline contention. The tool is based on x86's load latency and precise store facility events provided by Intel CPUs. It was tested by Joe Mario and has proven to be useful, finding some cacheline contentions. Joe also wrote a blog about c2c tool with examples: https://joemario.github.io/blog/2016/09/01/c2c-blog/ excerpt of the content on this site: At a high level, “perf c2c” will show you: * The cachelines where false sharing was detected. * The readers and writers to those cachelines, and the offsets where those accesses occurred. * The pid, tid, instruction addr, function name, binary object name for those readers and writers. * The source file and line number for each reader and writer. * The average load latency for the loads to those cachelines. * Which numa nodes the samples a cacheline came from and which CPUs were involved. Using perf c2c is similar to using the Linux perf tool today. First collect data with “perf c2c record”, then generate a report output with “perf c2c report” There one finds extensive details on using the tool, with tips on reducing the volume of samples while still capturing enough to do its job. (Dick Fowles, Joe Mario, Don Zickus, Jiri Olsa) - The new 'perf sched timehist' tool provides tailored analysis of scheduling events. Example usage: perf sched record -- sleep 1 perf sched timehist By default it shows the individual schedule events, including the wait time (time between sched-out and next sched-in events for the task), the task scheduling delay (time between wakeup and actually running) and run time for the task: time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) -------- ------ ---------------- --------- --------- -------- 1.874569 [0011] gcc[31949] 0.014 0.000 1.148 1.874591 [0010] gcc[31951] 0.000 0.000 0.024 1.874603 [0010] migration/10[59] 3.350 0.004 0.011 1.874604 [0011] <idle> 1.148 0.000 0.035 1.874723 [0005] <idle> 0.016 0.000 1.383 1.874746 [0005] gcc[31949] 0.153 0.078 0.022 ... Times are in msec.usec. (David Ahern, Namhyung Kim) - Add CPU vendor hardware event tables: Add JSON files with vendor event naming for Intel and Power8 processors, allowing users of tools like oprofile to keep using the event names they are used to, as well as people reading vendor documentation, where such naming is used. (Andi Kleen, Sukadev Bhattiprolu) You should see all the new events with 'perf list' and you should be able to search them, for example 'perf list miss' will list all the myriads of miss events. Other tooling features added were: - Cross-arch annotation support: o Improve ARM support in the annotation code, affecting 'perf annotate', 'perf report' and live annotation in 'perf top' (Kim Phillips) o Initial support for PowerPC in the annotation code (Ravi Bangoria) o Support AArch64 in the 'annotate' code, native/local and cross-arch/remote (Kim Phillips) - Allow considering just events in a given time interval, via the '--time start.s.ms,end.s.ms' command line, added to 'perf kmem', 'perf report', 'perf sched timehist' and 'perf script' (David Ahern) - Add option to stop printing a callchain at one of a given group of symbol names (David Ahern) - Track memory freed in 'perf kmem stat' (David Ahern) - Allow querying and setting .perfconfig variables (Taeung Song) - Show branch information in callchains (predicted, TSX aborts, loop iteractions, etc) (Jin Yao) - Dynamicly change verbosity level by pressing 'V' in the 'perf top/report' hists TUI browser (Alexis Berlemont) - Implement 'perf trace --delay' in the same fashion as in 'perf record --delay', to skip sampling workload initialization events (Alexis Berlemont) - Make vendor named events case insensitive in 'perf list', i.e. 'perf list LONGEST_LAT' works just the same as 'perf list longest_lat' (Andi Kleen) - Add unwinding support for jitdump (Stefano Sanfilippo) Tooling infrastructure changes: - Support linking perf with clang and LLVM libraries, initially statically, but this limitation will be lifted and shared libraries, when available, will be preferred to the static build, that should, as with other features, be enabled explicitly (Wang Nan) - Add initial support (and perf test entry) for tooling hooks, starting with 'record_start' and 'record_end', that will have as its initial user the eBPF infrastructure, where perf_ prefixed functions will be JITed and run when such hooks are called (Wang Nan) - Implement assorted libbpf improvements (Wang Nan)" ... and lots of other changes, features, cleanups and refactorings I did not list, see the shortlog and the git log for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (220 commits) perf/x86: Fix exclusion of BTS and LBR for Goldmont perf tools: Explicitly document that --children is enabled by default perf sched timehist: Cleanup idle_max_cpu handling perf sched timehist: Handle zero sample->tid properly perf callchain: Introduce callchain_cursor__copy() perf sched: Cleanup option processing perf sched timehist: Improve error message when analyzing wrong file perf tools: Move perf build related variables under non fixdep leg perf tools: Force fixdep compilation at the start of the build perf tools: Move PERF-VERSION-FILE target into rules area perf build: Check LLVM version in feature check perf annotate: Show raw form for jump instruction with indirect target perf tools: Add non config targets perf tools: Cleanup build directory before each test perf tools: Move python/perf.so target into rules area perf tools: Move install-gtk target into rules area tools build: Move tabs to spaces where suitable tools build: Make the .cmd file more readable perf clang: Compile BPF script using builtin clang support perf clang: Support compile IR to BPF object and add testcase ...
2016-12-12Merge branch 'mm-pat-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull mm/PAT cleanup from Ingo Molnar: "A single cleanup for a generic interface that was originally introduced for PAT" * 'mm-pat-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/pat, mm: Make track_pfn_insert() return void