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2013-09-30mm/hwpoison: fix the lack of one reference count against poisoned pageWanpeng Li
The lack of one reference count against poisoned page for hwpoison_inject w/o hwpoison_filter enabled result in hwpoison detect -1 users still referenced the page, however, the number should be 0 except the poison handler held one after successfully unmap. This patch fix it by hold one referenced count against poisoned page for hwpoison_inject w/ and w/o hwpoison_filter enabled. Before patch: [ 71.902112] Injecting memory failure at pfn 224706 [ 71.902137] MCE 0x224706: dirty LRU page recovery: Failed [ 71.902138] MCE 0x224706: dirty LRU page still referenced by -1 users After patch: [ 94.710860] Injecting memory failure at pfn 215b68 [ 94.710885] MCE 0x215b68: dirty LRU page recovery: Recovered Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm/hwpoison: fix false report on 2nd attempt at page recoveryWanpeng Li
If the page is poisoned by software injection w/ MF_COUNT_INCREASED flag, there is a false report during the 2nd attempt at page recovery which is not truthful. This patch fixes it by reporting the first attempt to try free buddy page recovery if MF_COUNT_INCREASED is set. Before patch: [ 346.332041] Injecting memory failure at pfn 200010 [ 346.332189] MCE 0x200010: free buddy, 2nd try page recovery: Delayed After patch: [ 297.742600] Injecting memory failure at pfn 200010 [ 297.742941] MCE 0x200010: free buddy page recovery: Delayed Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm/hwpoison: fix test for a transparent huge pageWanpeng Li
PageTransHuge() can't guarantee the page is a transparent huge page since it returns true for both transparent huge and hugetlbfs pages. This patch fixes it by checking the page is also !hugetlbfs page. Before patch: [ 121.571128] Injecting memory failure at pfn 23a200 [ 121.571141] MCE 0x23a200: huge page recovery: Delayed [ 140.355100] MCE: Memory failure is now running on 0x23a200 After patch: [ 94.290793] Injecting memory failure at pfn 23a000 [ 94.290800] MCE 0x23a000: huge page recovery: Delayed [ 105.722303] MCE: Software-unpoisoned page 0x23a000 Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm/hwpoison: fix traversal of hugetlbfs pages to avoid printk floodWanpeng Li
madvise_hwpoison won't check if the page is small page or huge page and traverses in small page granularity against the range unconditionally, which result in a printk flood "MCE xxx: already hardware poisoned" if the page is a huge page. This patch fixes it by using compound_order(compound_head(page)) for huge page iterator. Testcase: #define _GNU_SOURCE #include <stdlib.h> #include <stdio.h> #include <sys/mman.h> #include <unistd.h> #include <fcntl.h> #include <sys/types.h> #include <errno.h> #define PAGES_TO_TEST 3 #define PAGE_SIZE 4096 * 512 int main(void) { char *mem; int i; mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, 0, 0); if (madvise(mem, PAGES_TO_TEST * PAGE_SIZE, MADV_HWPOISON) == -1) return -1; munmap(mem, PAGES_TO_TEST * PAGE_SIZE); return 0; } Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm/mlock.c: prevent walking off the end of a pagetable in no-pmd configurationVlastimil Babka
The function __munlock_pagevec_fill() introduced in commit 7a8010cd3627 ("mm: munlock: manual pte walk in fast path instead of follow_page_mask()") uses pmd_addr_end() for restricting its operation within current page table. This is insufficient on architectures/configurations where pmd is folded and pmd_addr_end() just returns the end of the full range to be walked. In this case, it allows pte++ to walk off the end of a page table resulting in unpredictable behaviour. This patch fixes the function by using pgd_addr_end() and pud_addr_end() before pmd_addr_end(), which will yield correct page table boundary on all configurations. This is similar to what existing page walkers do when walking each level of the page table. Additionaly, the patch clarifies a comment for get_locked_pte() call in the function. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Bob Liu <bob.liu@oracle.com> Cc: Jörn Engel <joern@logfs.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm: avoid reinserting isolated balloon pages into LRU listsRafael Aquini
Isolated balloon pages can wrongly end up in LRU lists when migrate_pages() finishes its round without draining all the isolated page list. The same issue can happen when reclaim_clean_pages_from_list() tries to reclaim pages from an isolated page list, before migration, in the CMA path. Such balloon page leak opens a race window against LRU lists shrinkers that leads us to the following kernel panic: BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [<ffffffff810c2625>] shrink_page_list+0x24e/0x897 PGD 3cda2067 PUD 3d713067 PMD 0 Oops: 0000 [#1] SMP CPU: 0 PID: 340 Comm: kswapd0 Not tainted 3.12.0-rc1-22626-g4367597 #87 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 RIP: shrink_page_list+0x24e/0x897 RSP: 0000:ffff88003da499b8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88003e82bd60 RCX: 00000000000657d5 RDX: 0000000000000000 RSI: 000000000000031f RDI: ffff88003e82bd40 RBP: ffff88003da49ab0 R08: 0000000000000001 R09: 0000000081121a45 R10: ffffffff81121a45 R11: ffff88003c4a9a28 R12: ffff88003e82bd40 R13: ffff88003da0e800 R14: 0000000000000001 R15: ffff88003da49d58 FS: 0000000000000000(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000067d9000 CR3: 000000003ace5000 CR4: 00000000000407b0 Call Trace: shrink_inactive_list+0x240/0x3de shrink_lruvec+0x3e0/0x566 __shrink_zone+0x94/0x178 shrink_zone+0x3a/0x82 balance_pgdat+0x32a/0x4c2 kswapd+0x2f0/0x372 kthread+0xa2/0xaa ret_from_fork+0x7c/0xb0 Code: 80 7d 8f 01 48 83 95 68 ff ff ff 00 4c 89 e7 e8 5a 7b 00 00 48 85 c0 49 89 c5 75 08 80 7d 8f 00 74 3e eb 31 48 8b 80 18 01 00 00 <48> 8b 74 0d 48 8b 78 30 be 02 00 00 00 ff d2 eb RIP [<ffffffff810c2625>] shrink_page_list+0x24e/0x897 RSP <ffff88003da499b8> CR2: 0000000000000028 ---[ end trace 703d2451af6ffbfd ]--- Kernel panic - not syncing: Fatal exception This patch fixes the issue, by assuring the proper tests are made at putback_movable_pages() & reclaim_clean_pages_from_list() to avoid isolated balloon pages being wrongly reinserted in LRU lists. [akpm@linux-foundation.org: clarify awkward comment text] Signed-off-by: Rafael Aquini <aquini@redhat.com> Reported-by: Luiz Capitulino <lcapitulino@redhat.com> Tested-by: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages ↵Darrick J. Wong
snapshotting) was ignored The "force" parameter in __blk_queue_bounce was being ignored, which means that stable page snapshots are not always happening (on ext3). This of course leads to DIF disks reporting checksum errors, so fix this regression. The regression was introduced in commit 6bc454d15004 ("bounce: Refactor __blk_queue_bounce to not use bi_io_vec") Reported-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Cc: Kent Overstreet <koverstreet@google.com> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30mm/compaction.c: periodically schedule when freeing pagesDavid Rientjes
We've been getting warnings about an excessive amount of time spent allocating pages for migration during memory compaction without scheduling. isolate_freepages_block() already periodically checks for contended locks or the need to schedule, but isolate_freepages() never does. When a zone is massively long and no suitable targets can be found, this iteration can be quite expensive without ever doing cond_resched(). Check periodically for the need to reschedule while the compaction free scanner iterates. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-30revert "mm/memory-hotplug: fix lowmem count overflow when offline pages"Joonyoung Shim
This reverts commit cea27eb2a202 ("mm/memory-hotplug: fix lowmem count overflow when offline pages"). The fixed bug by commit cea27eb was fixed to another way by commit 3dcc0571cd64 ("mm: correctly update zone->managed_pages"). That commit enhances memory_hotplug.c to adjust totalhigh_pages when hot-removing memory, for details please refer to: http://marc.info/?l=linux-mm&m=136957578620221&w=2 As a result, commit cea27eb2a202 currently causes duplicated decreasing of totalhigh_pages, thus the revert. Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Jiang Liu <liuj97@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25mm: Place preemption point in do_mlockall() loopPaul E. McKenney
There is a loop in do_mlockall() that lacks a preemption point, which means that the following can happen on non-preemptible builds of the kernel. Dave Jones reports: "My fuzz tester keeps hitting this. Every instance shows the non-irq stack came in from mlockall. I'm only seeing this on one box, but that has more ram (8gb) than my other machines, which might explain it. INFO: rcu_preempt self-detected stall on CPU { 3} (t=6500 jiffies g=470344 c=470343 q=0) sending NMI to all CPUs: NMI backtrace for cpu 3 CPU: 3 PID: 29664 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #32 Call Trace: lru_add_drain_all+0x15/0x20 SyS_mlockall+0xa5/0x1a0 tracesys+0xdd/0xe2" This commit addresses this problem by inserting the required preemption point. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg, vmscan: integrate soft reclaim tighter with zone shrinking code"Andrew Morton
Revert commit 3b38722efd9f ("memcg, vmscan: integrate soft reclaim tighter with zone shrinking code") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg: get rid of soft-limit tree infrastructure"Andrew Morton
Revert commit e883110aad71 ("memcg: get rid of soft-limit tree infrastructure") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "vmscan, memcg: do softlimit reclaim also for targeted reclaim"Andrew Morton
Revert commit a5b7c87f9207 ("vmscan, memcg: do softlimit reclaim also for targeted reclaim") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg: enhance memcg iterator to support predicates"Andrew Morton
Revert commit de57780dc659 ("memcg: enhance memcg iterator to support predicates") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg: track children in soft limit excess to improve soft limit"Andrew Morton
Revert commit 7d910c054be4 ("memcg: track children in soft limit excess to improve soft limit") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg, vmscan: do not attempt soft limit reclaim if it would not ↵Andrew Morton
scan anything" Revert commit e839b6a1c8d0 ("memcg, vmscan: do not attempt soft limit reclaim if it would not scan anything") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg: track all children over limit in the root"Andrew Morton
Revert commit 1be171d60bdd ("memcg: track all children over limit in the root") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25revert "memcg, vmscan: do not fall into reclaim-all pass too quickly"Andrew Morton
Revert commit e975de998b96 ("memcg, vmscan: do not fall into reclaim-all pass too quickly") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-15Merge branch 'slab/next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux Pull SLAB update from Pekka Enberg: "Nothing terribly exciting here apart from Christoph's kmalloc unification patches that brings sl[aou]b implementations closer to each other" * 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: slab: Use correct GFP_DMA constant slub: remove verify_mem_not_deleted() mm/sl[aou]b: Move kmallocXXX functions to common code mm, slab_common: add 'unlikely' to size check of kmalloc_slab() mm/slub.c: beautify code for removing redundancy 'break' statement. slub: Remove unnecessary page NULL check slub: don't use cpu partial pages on UP mm/slub: beautify code for 80 column limitation and tab alignment mm/slub: remove 'per_cpu' which is useless variable
2013-09-13Merge git://git.kvack.org/~bcrl/aio-nextLinus Torvalds
Pull aio changes from Ben LaHaise: "First off, sorry for this pull request being late in the merge window. Al had raised a couple of concerns about 2 items in the series below. I addressed the first issue (the race introduced by Gu's use of mm_populate()), but he has not provided any further details on how he wants to rework the anon_inode.c changes (which were sent out months ago but have yet to be commented on). The bulk of the changes have been sitting in the -next tree for a few months, with all the issues raised being addressed" * git://git.kvack.org/~bcrl/aio-next: (22 commits) aio: rcu_read_lock protection for new rcu_dereference calls aio: fix race in ring buffer page lookup introduced by page migration support aio: fix rcu sparse warnings introduced by ioctx table lookup patch aio: remove unnecessary debugging from aio_free_ring() aio: table lookup: verify ctx pointer staging/lustre: kiocb->ki_left is removed aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3" aio: be defensive to ensure request batching is non-zero instead of BUG_ON() aio: convert the ioctx list to table lookup v3 aio: double aio_max_nr in calculations aio: Kill ki_dtor aio: Kill ki_users aio: Kill unneeded kiocb members aio: Kill aio_rw_vect_retry() aio: Don't use ctx->tail unnecessarily aio: io_cancel() no longer returns the io_event aio: percpu ioctx refcount aio: percpu reqs_available aio: reqs_active -> reqs_available aio: fix build when migration is disabled ...
2013-09-12Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge more patches from Andrew Morton: "The rest of MM. Plus one misc cleanup" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits) mm/Kconfig: add MMU dependency for MIGRATION. kernel: replace strict_strto*() with kstrto*() mm, thp: count thp_fault_fallback anytime thp fault fails thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page() thp: do_huge_pmd_anonymous_page() cleanup thp: move maybe_pmd_mkwrite() out of mk_huge_pmd() mm: cleanup add_to_page_cache_locked() thp: account anon transparent huge pages into NR_ANON_PAGES truncate: drop 'oldsize' truncate_pagecache() parameter mm: make lru_add_drain_all() selective memcg: document cgroup dirty/writeback memory statistics memcg: add per cgroup writeback pages accounting memcg: check for proper lock held in mem_cgroup_update_page_stat memcg: remove MEMCG_NR_FILE_MAPPED memcg: reduce function dereference memcg: avoid overflow caused by PAGE_ALIGN memcg: rename RESOURCE_MAX to RES_COUNTER_MAX memcg: correct RESOURCE_MAX to ULLONG_MAX mm: memcg: do not trap chargers with full callstack on OOM mm: memcg: rework and document OOM waiting and wakeup ...
2013-09-12mm/Kconfig: add MMU dependency for MIGRATION.Chen Gang
MIGRATION must depend on MMU, or allmodconfig for the nommu sh architecture fails to build: CC mm/migrate.o mm/migrate.c: In function 'remove_migration_pte': mm/migrate.c:134:3: error: implicit declaration of function 'pmd_trans_huge' [-Werror=implicit-function-declaration] if (pmd_trans_huge(*pmd)) ^ mm/migrate.c:149:2: error: implicit declaration of function 'is_swap_pte' [-Werror=implicit-function-declaration] if (!is_swap_pte(pte)) ^ ... Also let CMA depend on MMU, or when NOMMU, if we select CMA, it will select MIGRATION by force. Signed-off-by: Chen Gang <gang.chen@asianux.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm, thp: count thp_fault_fallback anytime thp fault failsDavid Rientjes
Currently, thp_fault_fallback in vmstat only gets incremented if a hugepage allocation fails. If current's memcg hits its limit or the page fault handler returns an error, it is incorrectly accounted as a successful thp_fault_alloc. Count thp_fault_fallback anytime the page fault handler falls back to using regular pages and only count thp_fault_alloc when a hugepage has actually been faulted. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()Kirill A. Shutemov
do_huge_pmd_anonymous_page() has copy-pasted piece of handle_mm_fault() to handle fallback path. Let's consolidate code back by introducing VM_FAULT_FALLBACK return code. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12thp: do_huge_pmd_anonymous_page() cleanupKirill A. Shutemov
Minor cleanup: unindent most code of the fucntion by inverting one condition. It's preparation for the next patch. No functional changes. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Hillf Danton <dhillf@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()Kirill A. Shutemov
It's confusing that mk_huge_pmd() has semantics different from mk_pte() or mk_pmd(). I spent some time on debugging issue cased by this inconsistency. Let's move maybe_pmd_mkwrite() out of mk_huge_pmd() and adjust prototype to match mk_pte(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: cleanup add_to_page_cache_locked()Kirill A. Shutemov
Make add_to_page_cache_locked() cleaner: - unindent most code of the function by inverting one condition; - streamline code no-error path; - move insert error path outside normal code path; - call radix_tree_preload_end() earlier; No functional changes. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12thp: account anon transparent huge pages into NR_ANON_PAGESKirill A. Shutemov
We use NR_ANON_PAGES as base for reporting AnonPages to user. There's not much sense in not accounting transparent huge pages there, but add them on printing to user. Let's account transparent huge pages in NR_ANON_PAGES in the first place. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Ning Qu <quning@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12truncate: drop 'oldsize' truncate_pagecache() parameterKirill A. Shutemov
truncate_pagecache() doesn't care about old size since commit cedabed49b39 ("vfs: Fix vmtruncate() regression"). Let's drop it. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: make lru_add_drain_all() selectiveChris Metcalf
make lru_add_drain_all() only selectively interrupt the cpus that have per-cpu free pages that can be drained. This is important in nohz mode where calling mlockall(), for example, otherwise will interrupt every core unnecessarily. This is important on workloads where nohz cores are handling 10 Gb traffic in userspace. Those CPUs do not enter the kernel and place pages into LRU pagevecs and they really, really don't want to be interrupted, or they drop packets on the floor. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: add per cgroup writeback pages accountingSha Zhengju
Add memcg routines to count writeback pages, later dirty pages will also be accounted. After Kame's commit 89c06bd52fb9 ("memcg: use new logic for page stat accounting"), we can use 'struct page' flag to test page state instead of per page_cgroup flag. But memcg has a feature to move a page from a cgroup to another one and may have race between "move" and "page stat accounting". So in order to avoid the race we have designed a new lock: mem_cgroup_begin_update_page_stat() modify page information -->(a) mem_cgroup_update_page_stat() -->(b) mem_cgroup_end_update_page_stat() It requires both (a) and (b)(writeback pages accounting) to be pretected in mem_cgroup_{begin/end}_update_page_stat(). It's full no-op for !CONFIG_MEMCG, almost no-op if memcg is disabled (but compiled in), rcu read lock in the most cases (no task is moving), and spin_lock_irqsave on top in the slow path. There're two writeback interfaces to modify: test_{clear/set}_page_writeback(). And the lock order is: --> memcg->move_lock --> mapping->tree_lock Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Greg Thelen <gthelen@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: check for proper lock held in mem_cgroup_update_page_statSha Zhengju
We should call mem_cgroup_begin_update_page_stat() before mem_cgroup_update_page_stat() to get proper locks, however the latter doesn't do any checking that we use proper locking, which would be hard. Suggested by Michal Hock we could at least test for rcu_read_lock_held() because RCU is held if !mem_cgroup_disabled(). Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Greg Thelen <gthelen@google.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: remove MEMCG_NR_FILE_MAPPEDSha Zhengju
While accounting memcg page stat, it's not worth to use MEMCG_NR_FILE_MAPPED as an extra layer of indirection because of the complexity and presumed performance overhead. We can use MEM_CGROUP_STAT_FILE_MAPPED directly. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: rename RESOURCE_MAX to RES_COUNTER_MAXSha Zhengju
RESOURCE_MAX is far too general name, change it to RES_COUNTER_MAX. Signed-off-by: Sha Zhengju <handai.szj@taobao.com> Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: memcg: do not trap chargers with full callstack on OOMJohannes Weiner
The memcg OOM handling is incredibly fragile and can deadlock. When a task fails to charge memory, it invokes the OOM killer and loops right there in the charge code until it succeeds. Comparably, any other task that enters the charge path at this point will go to a waitqueue right then and there and sleep until the OOM situation is resolved. The problem is that these tasks may hold filesystem locks and the mmap_sem; locks that the selected OOM victim may need to exit. For example, in one reported case, the task invoking the OOM killer was about to charge a page cache page during a write(), which holds the i_mutex. The OOM killer selected a task that was just entering truncate() and trying to acquire the i_mutex: OOM invoking task: mem_cgroup_handle_oom+0x241/0x3b0 mem_cgroup_cache_charge+0xbe/0xe0 add_to_page_cache_locked+0x4c/0x140 add_to_page_cache_lru+0x22/0x50 grab_cache_page_write_begin+0x8b/0xe0 ext3_write_begin+0x88/0x270 generic_file_buffered_write+0x116/0x290 __generic_file_aio_write+0x27c/0x480 generic_file_aio_write+0x76/0xf0 # takes ->i_mutex do_sync_write+0xea/0x130 vfs_write+0xf3/0x1f0 sys_write+0x51/0x90 system_call_fastpath+0x18/0x1d OOM kill victim: do_truncate+0x58/0xa0 # takes i_mutex do_last+0x250/0xa30 path_openat+0xd7/0x440 do_filp_open+0x49/0xa0 do_sys_open+0x106/0x240 sys_open+0x20/0x30 system_call_fastpath+0x18/0x1d The OOM handling task will retry the charge indefinitely while the OOM killed task is not releasing any resources. A similar scenario can happen when the kernel OOM killer for a memcg is disabled and a userspace task is in charge of resolving OOM situations. In this case, ALL tasks that enter the OOM path will be made to sleep on the OOM waitqueue and wait for userspace to free resources or increase the group's limit. But a userspace OOM handler is prone to deadlock itself on the locks held by the waiting tasks. For example one of the sleeping tasks may be stuck in a brk() call with the mmap_sem held for writing but the userspace handler, in order to pick an optimal victim, may need to read files from /proc/<pid>, which tries to acquire the same mmap_sem for reading and deadlocks. This patch changes the way tasks behave after detecting a memcg OOM and makes sure nobody loops or sleeps with locks held: 1. When OOMing in a user fault, invoke the OOM killer and restart the fault instead of looping on the charge attempt. This way, the OOM victim can not get stuck on locks the looping task may hold. 2. When OOMing in a user fault but somebody else is handling it (either the kernel OOM killer or a userspace handler), don't go to sleep in the charge context. Instead, remember the OOMing memcg in the task struct and then fully unwind the page fault stack with -ENOMEM. pagefault_out_of_memory() will then call back into the memcg code to check if the -ENOMEM came from the memcg, and then either put the task to sleep on the memcg's OOM waitqueue or just restart the fault. The OOM victim can no longer get stuck on any lock a sleeping task may hold. Debugged by Michal Hocko. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: azurIt <azurit@pobox.sk> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: memcg: rework and document OOM waiting and wakeupJohannes Weiner
The memcg OOM handler open-codes a sleeping lock for OOM serialization (trylock, wait, repeat) because the required locking is so specific to memcg hierarchies. However, it would be nice if this construct would be clearly recognizable and not be as obfuscated as it is right now. Clean up as follows: 1. Remove the return value of mem_cgroup_oom_unlock() 2. Rename mem_cgroup_oom_lock() to mem_cgroup_oom_trylock(). 3. Pull the prepare_to_wait() out of the memcg_oom_lock scope. This makes it more obvious that the task has to be on the waitqueue before attempting to OOM-trylock the hierarchy, to not miss any wakeups before going to sleep. It just didn't matter until now because it was all lumped together into the global memcg_oom_lock spinlock section. 4. Pull the mem_cgroup_oom_notify() out of the memcg_oom_lock scope. It is proctected by the hierarchical OOM-lock. 5. The memcg_oom_lock spinlock is only required to propagate the OOM lock in any given hierarchy atomically. Restrict its scope to mem_cgroup_oom_(trylock|unlock). 6. Do not wake up the waitqueue unconditionally at the end of the function. Only the lockholder has to wake up the next in line after releasing the lock. Note that the lockholder kicks off the OOM-killer, which in turn leads to wakeups from the uncharges of the exiting task. But a contender is not guaranteed to see them if it enters the OOM path after the OOM kills but before the lockholder releases the lock. Thus there has to be an explicit wakeup after releasing the lock. 7. Put the OOM task on the waitqueue before marking the hierarchy as under OOM as that is the point where we start to receive wakeups. No point in listening before being on the waitqueue. 8. Likewise, unmark the hierarchy before finishing the sleep, for symmetry. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12mm: memcg: enable memcg OOM killer only for user faultsJohannes Weiner
System calls and kernel faults (uaccess, gup) can handle an out of memory situation gracefully and just return -ENOMEM. Enable the memcg OOM killer only for user faults, where it's really the only option available. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: trivial cleanupsAndrew Morton
Clean up some mess made by the "Soft limit rework" series, and a few other things. Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg, vmscan: do not fall into reclaim-all pass too quicklyMichal Hocko
shrink_zone starts with soft reclaim pass first and then falls back to regular reclaim if nothing has been scanned. This behavior is natural but there is a catch. Memcg iterators, when used with the reclaim cookie, are designed to help to prevent from over reclaim by interleaving reclaimers (per node-zone-priority) so the tree walk might miss many (even all) nodes in the hierarchy e.g. when there are direct reclaimers racing with each other or with kswapd in the global case or multiple allocators reaching the limit for the target reclaim case. To make it even more complicated, targeted reclaim doesn't do the whole tree walk because it stops reclaiming once it reclaims sufficient pages. As a result groups over the limit might be missed, thus nothing is scanned, and reclaim would fall back to the reclaim all mode. This patch checks for the incomplete tree walk in shrink_zone. If no group has been visited and the hierarchy is soft reclaimable then we must have missed some groups, in which case the __shrink_zone is called again. This doesn't guarantee there will be some progress of course because the current reclaimer might be still racing with others but it would at least give a chance to start the walk without a big risk of reclaim latencies. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: track all children over limit in the rootMichal Hocko
Children in soft limit excess are currently tracked up the hierarchy in memcg->children_in_excess. Nevertheless there still might exist tons of groups that are not in hierarchy relation to the root cgroup (e.g. all first level groups if root_mem_cgroup->use_hierarchy == false). As the whole tree walk has to be done when the iteration starts at root_mem_cgroup the iterator should be able to skip the walk if there is no child above the limit without iterating them. This can be done easily if the root tracks all children rather than only hierarchical children. This is done by this patch which updates root_mem_cgroup children_in_excess if root_mem_cgroup->use_hierarchy == false so the root knows about all children in excess. Please note that this is not an issue for inner memcgs which have use_hierarchy == false because then only the single group is visited so no special optimization is necessary. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg, vmscan: do not attempt soft limit reclaim if it would not scan anythingMichal Hocko
mem_cgroup_should_soft_reclaim controls whether soft reclaim pass is done and it always says yes currently. Memcg iterators are clever to skip nodes that are not soft reclaimable quite efficiently but mem_cgroup_should_soft_reclaim can be more clever and do not start the soft reclaim pass at all if it knows that nothing would be scanned anyway. In order to do that, simply reuse mem_cgroup_soft_reclaim_eligible for the target group of the reclaim and allow the pass only if the whole subtree wouldn't be skipped. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: track children in soft limit excess to improve soft limitMichal Hocko
Soft limit reclaim has to check the whole reclaim hierarchy while doing the first pass of the reclaim. This leads to a higher system time which can be visible especially when there are many groups in the hierarchy. This patch adds a per-memcg counter of children in excess. It also restores MEM_CGROUP_TARGET_SOFTLIMIT into mem_cgroup_event_ratelimit for a proper batching. If a group crosses soft limit for the first time it increases parent's children_in_excess up the hierarchy. The similarly if a group gets below the limit it will decrease the counter. The transition phase is recorded in soft_contributed flag. mem_cgroup_soft_reclaim_eligible then uses this information to better decide whether to skip the node or the whole subtree. The rule is simple. Skip the node with a children in excess or skip the whole subtree otherwise. This has been tested by a stream IO (dd if=/dev/zero of=file with 4*MemTotal size) which is quite sensitive to overhead during reclaim. The load is running in a group with soft limit set to 0 and without any limit. Apart from that there was a hierarchy with ~500, 2k and 8k groups (two groups on each level) without any pages in them. base denotes to the kernel on which the whole series is based on, rework is the kernel before this patch and reworkoptim is with this patch applied: * Run with soft limit set to 0 Elapsed 0-0-limit/base: min: 88.21 max: 94.61 avg: 91.73 std: 2.65 runs: 3 0-0-limit/rework: min: 76.05 [86.2%] max: 79.08 [83.6%] avg: 77.84 [84.9%] std: 1.30 runs: 3 0-0-limit/reworkoptim: min: 77.98 [88.4%] max: 80.36 [84.9%] avg: 78.92 [86.0%] std: 1.03 runs: 3 System 0.5k-0-limit/base: min: 34.86 max: 36.42 avg: 35.89 std: 0.73 runs: 3 0.5k-0-limit/rework: min: 43.26 [124.1%] max: 48.95 [134.4%] avg: 46.09 [128.4%] std: 2.32 runs: 3 0.5k-0-limit/reworkoptim: min: 46.98 [134.8%] max: 50.98 [140.0%] avg: 48.49 [135.1%] std: 1.77 runs: 3 Elapsed 0.5k-0-limit/base: min: 88.50 max: 97.52 avg: 93.92 std: 3.90 runs: 3 0.5k-0-limit/rework: min: 75.92 [85.8%] max: 78.45 [80.4%] avg: 77.34 [82.3%] std: 1.06 runs: 3 0.5k-0-limit/reworkoptim: min: 75.79 [85.6%] max: 79.37 [81.4%] avg: 77.55 [82.6%] std: 1.46 runs: 3 System 2k-0-limit/base: min: 34.57 max: 37.65 avg: 36.34 std: 1.30 runs: 3 2k-0-limit/rework: min: 64.17 [185.6%] max: 68.20 [181.1%] avg: 66.21 [182.2%] std: 1.65 runs: 3 2k-0-limit/reworkoptim: min: 49.78 [144.0%] max: 52.99 [140.7%] avg: 51.00 [140.3%] std: 1.42 runs: 3 Elapsed 2k-0-limit/base: min: 92.61 max: 97.83 avg: 95.03 std: 2.15 runs: 3 2k-0-limit/rework: min: 78.33 [84.6%] max: 84.08 [85.9%] avg: 81.09 [85.3%] std: 2.35 runs: 3 2k-0-limit/reworkoptim: min: 75.72 [81.8%] max: 78.57 [80.3%] avg: 76.73 [80.7%] std: 1.30 runs: 3 System 8k-0-limit/base: min: 39.78 max: 42.09 avg: 41.09 std: 0.97 runs: 3 8k-0-limit/rework: min: 200.86 [504.9%] max: 265.42 [630.6%] avg: 241.80 [588.5%] std: 29.06 runs: 3 8k-0-limit/reworkoptim: min: 53.70 [135.0%] max: 54.89 [130.4%] avg: 54.43 [132.5%] std: 0.52 runs: 3 Elapsed 8k-0-limit/base: min: 95.11 max: 98.61 avg: 96.81 std: 1.43 runs: 3 8k-0-limit/rework: min: 246.96 [259.7%] max: 331.47 [336.1%] avg: 301.32 [311.2%] std: 38.52 runs: 3 8k-0-limit/reworkoptim: min: 76.79 [80.7%] max: 81.71 [82.9%] avg: 78.97 [81.6%] std: 2.05 runs: 3 System time is increased by 30-40% but it is reduced a lot comparing to kernel without this patch. The higher time can be explained by the fact that the original soft reclaim scanned at priority 0 so it was much more effective for this workload (which is basically touch once and writeback). The Elapsed time looks better though (~20%). * Run with no soft limit set System 0-no-limit/base: min: 42.18 max: 50.38 avg: 46.44 std: 3.36 runs: 3 0-no-limit/rework: min: 40.57 [96.2%] max: 47.04 [93.4%] avg: 43.82 [94.4%] std: 2.64 runs: 3 0-no-limit/reworkoptim: min: 40.45 [95.9%] max: 45.28 [89.9%] avg: 42.10 [90.7%] std: 2.25 runs: 3 Elapsed 0-no-limit/base: min: 75.97 max: 78.21 avg: 76.87 std: 0.96 runs: 3 0-no-limit/rework: min: 75.59 [99.5%] max: 80.73 [103.2%] avg: 77.64 [101.0%] std: 2.23 runs: 3 0-no-limit/reworkoptim: min: 77.85 [102.5%] max: 82.42 [105.4%] avg: 79.64 [103.6%] std: 1.99 runs: 3 System 0.5k-no-limit/base: min: 44.54 max: 46.93 avg: 46.12 std: 1.12 runs: 3 0.5k-no-limit/rework: min: 42.09 [94.5%] max: 46.16 [98.4%] avg: 43.92 [95.2%] std: 1.69 runs: 3 0.5k-no-limit/reworkoptim: min: 42.47 [95.4%] max: 45.67 [97.3%] avg: 44.06 [95.5%] std: 1.31 runs: 3 Elapsed 0.5k-no-limit/base: min: 78.26 max: 81.49 avg: 79.65 std: 1.36 runs: 3 0.5k-no-limit/rework: min: 77.01 [98.4%] max: 80.43 [98.7%] avg: 78.30 [98.3%] std: 1.52 runs: 3 0.5k-no-limit/reworkoptim: min: 76.13 [97.3%] max: 77.87 [95.6%] avg: 77.18 [96.9%] std: 0.75 runs: 3 System 2k-no-limit/base: min: 62.96 max: 69.14 avg: 66.14 std: 2.53 runs: 3 2k-no-limit/rework: min: 76.01 [120.7%] max: 81.06 [117.2%] avg: 78.17 [118.2%] std: 2.12 runs: 3 2k-no-limit/reworkoptim: min: 62.57 [99.4%] max: 66.10 [95.6%] avg: 64.53 [97.6%] std: 1.47 runs: 3 Elapsed 2k-no-limit/base: min: 76.47 max: 84.22 avg: 79.12 std: 3.60 runs: 3 2k-no-limit/rework: min: 89.67 [117.3%] max: 93.26 [110.7%] avg: 91.10 [115.1%] std: 1.55 runs: 3 2k-no-limit/reworkoptim: min: 76.94 [100.6%] max: 79.21 [94.1%] avg: 78.45 [99.2%] std: 1.07 runs: 3 System 8k-no-limit/base: min: 104.74 max: 151.34 avg: 129.21 std: 19.10 runs: 3 8k-no-limit/rework: min: 205.23 [195.9%] max: 285.94 [188.9%] avg: 258.98 [200.4%] std: 38.01 runs: 3 8k-no-limit/reworkoptim: min: 161.16 [153.9%] max: 184.54 [121.9%] avg: 174.52 [135.1%] std: 9.83 runs: 3 Elapsed 8k-no-limit/base: min: 125.43 max: 181.00 avg: 154.81 std: 22.80 runs: 3 8k-no-limit/rework: min: 254.05 [202.5%] max: 355.67 [196.5%] avg: 321.46 [207.6%] std: 47.67 runs: 3 8k-no-limit/reworkoptim: min: 193.77 [154.5%] max: 222.72 [123.0%] avg: 210.18 [135.8%] std: 12.13 runs: 3 Both System and Elapsed are in stdev with the base kernel for all configurations except for 8k where both System and Elapsed are up by 35%. I do not have a good explanation for this because there is no soft reclaim pass going on as no group is above the limit which is checked in mem_cgroup_should_soft_reclaim. Then I have tested kernel build with the same configuration to see the behavior with a more general behavior. * Soft limit set to 0 for the build System 0-0-limit/base: min: 242.70 max: 245.17 avg: 243.85 std: 1.02 runs: 3 0-0-limit/rework min: 237.86 [98.0%] max: 240.22 [98.0%] avg: 239.00 [98.0%] std: 0.97 runs: 3 0-0-limit/reworkoptim: min: 241.11 [99.3%] max: 243.53 [99.3%] avg: 242.01 [99.2%] std: 1.08 runs: 3 Elapsed 0-0-limit/base: min: 348.48 max: 360.86 avg: 356.04 std: 5.41 runs: 3 0-0-limit/rework min: 286.95 [82.3%] max: 290.26 [80.4%] avg: 288.27 [81.0%] std: 1.43 runs: 3 0-0-limit/reworkoptim: min: 286.55 [82.2%] max: 289.00 [80.1%] avg: 287.69 [80.8%] std: 1.01 runs: 3 System 0.5k-0-limit/base: min: 251.77 max: 254.41 avg: 252.70 std: 1.21 runs: 3 0.5k-0-limit/rework min: 286.44 [113.8%] max: 289.30 [113.7%] avg: 287.60 [113.8%] std: 1.23 runs: 3 0.5k-0-limit/reworkoptim: min: 252.18 [100.2%] max: 253.16 [99.5%] avg: 252.62 [100.0%] std: 0.41 runs: 3 Elapsed 0.5k-0-limit/base: min: 347.83 max: 353.06 avg: 350.04 std: 2.21 runs: 3 0.5k-0-limit/rework min: 290.19 [83.4%] max: 295.62 [83.7%] avg: 293.12 [83.7%] std: 2.24 runs: 3 0.5k-0-limit/reworkoptim: min: 293.91 [84.5%] max: 294.87 [83.5%] avg: 294.29 [84.1%] std: 0.42 runs: 3 System 2k-0-limit/base: min: 263.05 max: 271.52 avg: 267.94 std: 3.58 runs: 3 2k-0-limit/rework min: 458.99 [174.5%] max: 468.31 [172.5%] avg: 464.45 [173.3%] std: 3.97 runs: 3 2k-0-limit/reworkoptim: min: 267.10 [101.5%] max: 279.38 [102.9%] avg: 272.78 [101.8%] std: 5.05 runs: 3 Elapsed 2k-0-limit/base: min: 372.33 max: 379.32 avg: 375.47 std: 2.90 runs: 3 2k-0-limit/rework min: 334.40 [89.8%] max: 339.52 [89.5%] avg: 337.44 [89.9%] std: 2.20 runs: 3 2k-0-limit/reworkoptim: min: 301.47 [81.0%] max: 319.19 [84.1%] avg: 307.90 [82.0%] std: 8.01 runs: 3 System 8k-0-limit/base: min: 320.50 max: 332.10 avg: 325.46 std: 4.88 runs: 3 8k-0-limit/rework min: 1115.76 [348.1%] max: 1165.66 [351.0%] avg: 1132.65 [348.0%] std: 23.34 runs: 3 8k-0-limit/reworkoptim: min: 403.75 [126.0%] max: 409.22 [123.2%] avg: 406.16 [124.8%] std: 2.28 runs: 3 Elapsed 8k-0-limit/base: min: 475.48 max: 585.19 avg: 525.54 std: 45.30 runs: 3 8k-0-limit/rework min: 616.25 [129.6%] max: 625.90 [107.0%] avg: 620.68 [118.1%] std: 3.98 runs: 3 8k-0-limit/reworkoptim: min: 420.18 [88.4%] max: 428.28 [73.2%] avg: 423.05 [80.5%] std: 3.71 runs: 3 Apart from 8k the system time is comparable with the base kernel while Elapsed is up to 20% better with all configurations. * No soft limit set System 0-no-limit/base: min: 234.76 max: 237.42 avg: 236.25 std: 1.11 runs: 3 0-no-limit/rework min: 233.09 [99.3%] max: 238.65 [100.5%] avg: 236.09 [99.9%] std: 2.29 runs: 3 0-no-limit/reworkoptim: min: 236.12 [100.6%] max: 240.53 [101.3%] avg: 237.94 [100.7%] std: 1.88 runs: 3 Elapsed 0-no-limit/base: min: 288.52 max: 295.42 avg: 291.29 std: 2.98 runs: 3 0-no-limit/rework min: 283.17 [98.1%] max: 284.33 [96.2%] avg: 283.78 [97.4%] std: 0.48 runs: 3 0-no-limit/reworkoptim: min: 288.50 [100.0%] max: 290.79 [98.4%] avg: 289.78 [99.5%] std: 0.95 runs: 3 System 0.5k-no-limit/base: min: 286.51 max: 293.23 avg: 290.21 std: 2.78 runs: 3 0.5k-no-limit/rework min: 291.69 [101.8%] max: 294.38 [100.4%] avg: 292.97 [101.0%] std: 1.10 runs: 3 0.5k-no-limit/reworkoptim: min: 277.05 [96.7%] max: 288.76 [98.5%] avg: 284.17 [97.9%] std: 5.11 runs: 3 Elapsed 0.5k-no-limit/base: min: 294.94 max: 298.92 avg: 296.47 std: 1.75 runs: 3 0.5k-no-limit/rework min: 292.55 [99.2%] max: 294.21 [98.4%] avg: 293.55 [99.0%] std: 0.72 runs: 3 0.5k-no-limit/reworkoptim: min: 294.41 [99.8%] max: 301.67 [100.9%] avg: 297.78 [100.4%] std: 2.99 runs: 3 System 2k-no-limit/base: min: 443.41 max: 466.66 avg: 457.66 std: 10.19 runs: 3 2k-no-limit/rework min: 490.11 [110.5%] max: 516.02 [110.6%] avg: 501.42 [109.6%] std: 10.83 runs: 3 2k-no-limit/reworkoptim: min: 435.25 [98.2%] max: 458.11 [98.2%] avg: 446.73 [97.6%] std: 9.33 runs: 3 Elapsed 2k-no-limit/base: min: 330.85 max: 333.75 avg: 332.52 std: 1.23 runs: 3 2k-no-limit/rework min: 343.06 [103.7%] max: 349.59 [104.7%] avg: 345.95 [104.0%] std: 2.72 runs: 3 2k-no-limit/reworkoptim: min: 330.01 [99.7%] max: 333.92 [100.1%] avg: 332.22 [99.9%] std: 1.64 runs: 3 System 8k-no-limit/base: min: 1175.64 max: 1259.38 avg: 1222.39 std: 34.88 runs: 3 8k-no-limit/rework min: 1226.31 [104.3%] max: 1241.60 [98.6%] avg: 1233.74 [100.9%] std: 6.25 runs: 3 8k-no-limit/reworkoptim: min: 1023.45 [87.1%] max: 1056.74 [83.9%] avg: 1038.92 [85.0%] std: 13.69 runs: 3 Elapsed 8k-no-limit/base: min: 613.36 max: 619.60 avg: 616.47 std: 2.55 runs: 3 8k-no-limit/rework min: 627.56 [102.3%] max: 642.33 [103.7%] avg: 633.44 [102.8%] std: 6.39 runs: 3 8k-no-limit/reworkoptim: min: 545.89 [89.0%] max: 555.36 [89.6%] avg: 552.06 [89.6%] std: 4.37 runs: 3 and these numbers look good as well. System time is around 100% (suprisingly better for the 8k case) and Elapsed is copies that trend. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: enhance memcg iterator to support predicatesMichal Hocko
The caller of the iterator might know that some nodes or even subtrees should be skipped but there is no way to tell iterators about that so the only choice left is to let iterators to visit each node and do the selection outside of the iterating code. This, however, doesn't scale well with hierarchies with many groups where only few groups are interesting. This patch adds mem_cgroup_iter_cond variant of the iterator with a callback which gets called for every visited node. There are three possible ways how the callback can influence the walk. Either the node is visited, it is skipped but the tree walk continues down the tree or the whole subtree of the current group is skipped. [hughd@google.com: fix memcg-less page reclaim] Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@openvz.org> Cc: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Ying Han <yinghan@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12vmscan, memcg: do softlimit reclaim also for targeted reclaimMichal Hocko
Soft reclaim has been done only for the global reclaim (both background and direct). Since "memcg: integrate soft reclaim tighter with zone shrinking code" there is no reason for this limitation anymore as the soft limit reclaim doesn't use any special code paths and it is a part of the zone shrinking code which is used by both global and targeted reclaims. From the semantic point of view it is natural to consider soft limit before touching all groups in the hierarchy tree which is touching the hard limit because soft limit tells us where to push back when there is a memory pressure. It is not important whether the pressure comes from the limit or imbalanced zones. This patch simply enables soft reclaim unconditionally in mem_cgroup_should_soft_reclaim so it is enabled for both global and targeted reclaim paths. mem_cgroup_soft_reclaim_eligible needs to learn about the root of the reclaim to know where to stop checking soft limit state of parents up the hierarchy. Say we have A (over soft limit) \ B (below s.l., hit the hard limit) / \ C D (below s.l.) B is the source of the outside memory pressure now for D but we shouldn't soft reclaim it because it is behaving well under B subtree and we can still reclaim from C (pressumably it is over the limit). mem_cgroup_soft_reclaim_eligible should therefore stop climbing up the hierarchy at B (root of the memory pressure). Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Glauber Costa <glommer@openvz.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: get rid of soft-limit tree infrastructureMichal Hocko
Now that the soft limit is integrated to the reclaim directly the whole soft-limit tree infrastructure is not needed anymore. Rip it out. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Glauber Costa <glommer@openvz.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Michel Lespinasse <walken@google.com> Cc: Ying Han <yinghan@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg, vmscan: integrate soft reclaim tighter with zone shrinking codeMichal Hocko
This patchset is sitting out of tree for quite some time without any objections. I would be really happy if it made it into 3.12. I do not want to push it too hard but I think this work is basically ready and waiting more doesn't help. The basic idea is quite simple. Pull soft reclaim into shrink_zone in the first step and get rid of the previous soft reclaim infrastructure. shrink_zone is done in two passes now. First it tries to do the soft limit reclaim and it falls back to reclaim-all mode if no group is over the limit or no pages have been scanned. The second pass happens at the same priority so the only time we waste is the memcg tree walk which has been updated in the third step to have only negligible overhead. As a bonus we will get rid of a _lot_ of code by this and soft reclaim will not stand out like before when it wasn't integrated into the zone shrinking code and it reclaimed at priority 0 (the testing results show that some workloads suffers from such an aggressive reclaim). The clean up is in a separate patch because I felt it would be easier to review that way. The second step is soft limit reclaim integration into targeted reclaim. It should be rather straight forward. Soft limit has been used only for the global reclaim so far but it makes sense for any kind of pressure coming from up-the-hierarchy, including targeted reclaim. The third step (patches 4-8) addresses the tree walk overhead by enhancing memcg iterators to enable skipping whole subtrees and tracking number of over soft limit children at each level of the hierarchy. This information is updated same way the old soft limit tree was updated (from memcg_check_events) so we shouldn't see an additional overhead. In fact mem_cgroup_update_soft_limit is much simpler than tree manipulation done previously. __shrink_zone uses mem_cgroup_soft_reclaim_eligible as a predicate for mem_cgroup_iter so the decision whether a particular group should be visited is done at the iterator level which allows us to decide to skip the whole subtree as well (if there is no child in excess). This reduces the tree walk overhead considerably. * TEST 1 ======== My primary test case was a parallel kernel build with 2 groups (make is running with -j8 with a distribution .config in a separate cgroup without any hard limit) on a 32 CPU machine booted with 1GB memory and both builds run taskset to Node 0 cpus. I was mostly interested in 2 setups. Default - no soft limit set and - and 0 soft limit set to both groups. The first one should tell us whether the rework regresses the default behavior while the second one should show us improvements in an extreme case where both workloads are always over the soft limit. /usr/bin/time -v has been used to collect the statistics and each configuration had 3 runs after fresh boot without any other load on the system. base is mmotm-2013-07-18-16-40 rework all 8 patches applied on top of base * No-limit User no-limit/base: min: 651.92 max: 672.65 avg: 664.33 std: 8.01 runs: 6 no-limit/rework: min: 657.34 [100.8%] max: 668.39 [99.4%] avg: 663.13 [99.8%] std: 3.61 runs: 6 System no-limit/base: min: 69.33 max: 71.39 avg: 70.32 std: 0.79 runs: 6 no-limit/rework: min: 69.12 [99.7%] max: 71.05 [99.5%] avg: 70.04 [99.6%] std: 0.59 runs: 6 Elapsed no-limit/base: min: 398.27 max: 422.36 avg: 408.85 std: 7.74 runs: 6 no-limit/rework: min: 386.36 [97.0%] max: 438.40 [103.8%] avg: 416.34 [101.8%] std: 18.85 runs: 6 The results are within noise. Elapsed time has a bigger variance but the average looks good. * 0-limit User 0-limit/base: min: 573.76 max: 605.63 avg: 585.73 std: 12.21 runs: 6 0-limit/rework: min: 645.77 [112.6%] max: 666.25 [110.0%] avg: 656.97 [112.2%] std: 7.77 runs: 6 System 0-limit/base: min: 69.57 max: 71.13 avg: 70.29 std: 0.54 runs: 6 0-limit/rework: min: 68.68 [98.7%] max: 71.40 [100.4%] avg: 69.91 [99.5%] std: 0.87 runs: 6 Elapsed 0-limit/base: min: 1306.14 max: 1550.17 avg: 1430.35 std: 90.86 runs: 6 0-limit/rework: min: 404.06 [30.9%] max: 465.94 [30.1%] avg: 434.81 [30.4%] std: 22.68 runs: 6 The improvement is really huge here (even bigger than with my previous testing and I suspect that this highly depends on the storage). Page fault statistics tell us at least part of the story: Minor 0-limit/base: min: 37180461.00 max: 37319986.00 avg: 37247470.00 std: 54772.71 runs: 6 0-limit/rework: min: 36751685.00 [98.8%] max: 36805379.00 [98.6%] avg: 36774506.33 [98.7%] std: 17109.03 runs: 6 Major 0-limit/base: min: 170604.00 max: 221141.00 avg: 196081.83 std: 18217.01 runs: 6 0-limit/rework: min: 2864.00 [1.7%] max: 10029.00 [4.5%] avg: 5627.33 [2.9%] std: 2252.71 runs: 6 Same as with my previous testing Minor faults are more or less within noise but Major fault count is way bellow the base kernel. While this looks as a nice win it is fair to say that 0-limit configuration is quite artificial. So I was playing with 0-no-limit loads as well. * TEST 2 ======== The following results are from 2 groups configuration on a 16GB machine (single NUMA node). - A running stream IO (dd if=/dev/zero of=local.file bs=1024) with 2*TotalMem with 0 soft limit. - B running a mem_eater which consumes TotalMem-1G without any limit. The mem_eater consumes the memory in 100 chunks with 1s nap after each mmap+poppulate so that both loads have chance to fight for the memory. The expected result is that B shouldn't be reclaimed and A shouldn't see a big dropdown in elapsed time. User base: min: 2.68 max: 2.89 avg: 2.76 std: 0.09 runs: 3 rework: min: 3.27 [122.0%] max: 3.74 [129.4%] avg: 3.44 [124.6%] std: 0.21 runs: 3 System base: min: 86.26 max: 88.29 avg: 87.28 std: 0.83 runs: 3 rework: min: 81.05 [94.0%] max: 84.96 [96.2%] avg: 83.14 [95.3%] std: 1.61 runs: 3 Elapsed base: min: 317.28 max: 332.39 avg: 325.84 std: 6.33 runs: 3 rework: min: 281.53 [88.7%] max: 298.16 [89.7%] avg: 290.99 [89.3%] std: 6.98 runs: 3 System time improved slightly as well as Elapsed. My previous testing has shown worse numbers but this again seem to depend on the storage speed. My theory is that the writeback doesn't catch up and prio-0 soft reclaim falls into wait on writeback page too often in the base kernel. The patched kernel doesn't do that because the soft reclaim is done from the kswapd/direct reclaim context. This can be seen on the following graph nicely. The A's group usage_in_bytes regurarly drops really low very often. All 3 runs http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream.png resp. a detail of the single run http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/stream-one-run.png mem_eater seems to be doing better as well. It gets to the full allocation size faster as can be seen on the following graph: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/mem_eater-one-run.png /proc/meminfo collected during the test also shows that rework kernel hasn't swapped that much (well almost not at all): base: max: 123900 K avg: 56388.29 K rework: max: 300 K avg: 128.68 K kswapd and direct reclaim statistics are of no use unfortunatelly because soft reclaim is not accounted properly as the counters are hidden by global_reclaim() checks in the base kernel. * TEST 3 ======== Another test was the same configuration as TEST2 except the stream IO was replaced by a single kbuild (16 parallel jobs bound to Node0 cpus same as in TEST1) and mem_eater allocated TotalMem-200M so kbuild had only 200MB left. Kbuild did better with the rework kernel here as well: User base: min: 860.28 max: 872.86 avg: 868.03 std: 5.54 runs: 3 rework: min: 880.81 [102.4%] max: 887.45 [101.7%] avg: 883.56 [101.8%] std: 2.83 runs: 3 System base: min: 84.35 max: 85.06 avg: 84.79 std: 0.31 runs: 3 rework: min: 85.62 [101.5%] max: 86.09 [101.2%] avg: 85.79 [101.2%] std: 0.21 runs: 3 Elapsed base: min: 135.36 max: 243.30 avg: 182.47 std: 45.12 runs: 3 rework: min: 110.46 [81.6%] max: 116.20 [47.8%] avg: 114.15 [62.6%] std: 2.61 runs: 3 Minor base: min: 36635476.00 max: 36673365.00 avg: 36654812.00 std: 15478.03 runs: 3 rework: min: 36639301.00 [100.0%] max: 36695541.00 [100.1%] avg: 36665511.00 [100.0%] std: 23118.23 runs: 3 Major base: min: 14708.00 max: 53328.00 avg: 31379.00 std: 16202.24 runs: 3 rework: min: 302.00 [2.1%] max: 414.00 [0.8%] avg: 366.33 [1.2%] std: 47.22 runs: 3 Again we can see a significant improvement in Elapsed (it also seems to be more stable), there is a huge dropdown for the Major page faults and much more swapping: base: max: 583736 K avg: 112547.43 K rework: max: 4012 K avg: 124.36 K Graphs from all three runs show the variability of the kbuild quite nicely. It even seems that it took longer after every run with the base kernel which would be quite surprising as the source tree for the build is removed and caches are dropped after each run so the build operates on a freshly extracted sources everytime. http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater.png My other testing shows that this is just a matter of timing and other runs behave differently the std for Elapsed time is similar ~50. Example of other three runs: http://labs.suse.cz/mhocko/soft_limit_rework/stream_io-vs-mem_eater/kbuild-mem_eater2.png So to wrap this up. The series is still doing good and improves the soft limit. The testing results for bunch of cgroups with both stream IO and kbuild loads can be found in "memcg: track children in soft limit excess to improve soft limit". This patch: Memcg soft reclaim has been traditionally triggered from the global reclaim paths before calling shrink_zone. mem_cgroup_soft_limit_reclaim then picked up a group which exceeds the soft limit the most and reclaimed it with 0 priority to reclaim at least SWAP_CLUSTER_MAX pages. The infrastructure requires per-node-zone trees which hold over-limit groups and keep them up-to-date (via memcg_check_events) which is not cost free. Although this overhead hasn't turned out to be a bottle neck the implementation is suboptimal because mem_cgroup_update_tree has no idea which zones consumed memory over the limit so we could easily end up having a group on a node-zone tree having only few pages from that node-zone. This patch doesn't try to fix node-zone trees management because it seems that integrating soft reclaim into zone shrinking sounds much easier and more appropriate for several reasons. First of all 0 priority reclaim was a crude hack which might lead to big stalls if the group's LRUs are big and hard to reclaim (e.g. a lot of dirty/writeback pages). Soft reclaim should be applicable also to the targeted reclaim which is awkward right now without additional hacks. Last but not least the whole infrastructure eats quite some code. After this patch shrink_zone is done in 2 passes. First it tries to do the soft reclaim if appropriate (only for global reclaim for now to keep compatible with the original state) and fall back to ignoring soft limit if no group is eligible to soft reclaim or nothing has been scanned during the first pass. Only groups which are over their soft limit or any of their parents up the hierarchy is over the limit are considered eligible during the first pass. Soft limit tree which is not necessary anymore will be removed in the follow up patch to make this patch smaller and easier to review. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Glauber Costa <glommer@openvz.org> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ying Han <yinghan@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12memcg: remove redundant code in mem_cgroup_force_empty_write()Li Zefan
vfs guarantees the cgroup won't be destroyed, so it's redundant to get a css reference. Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 4 from Al Viro: "list_lru pile, mostly" This came out of Andrew's pile, Al ended up doing the merge work so that Andrew didn't have to. Additionally, a few fixes. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits) super: fix for destroy lrus list_lru: dynamically adjust node arrays shrinker: Kill old ->shrink API. shrinker: convert remaining shrinkers to count/scan API staging/lustre/libcfs: cleanup linux-mem.h staging/lustre/ptlrpc: convert to new shrinker API staging/lustre/obdclass: convert lu_object shrinker to count/scan API staging/lustre/ldlm: convert to shrinkers to count/scan API hugepage: convert huge zero page shrinker to new shrinker API i915: bail out earlier when shrinker cannot acquire mutex drivers: convert shrinkers to new count/scan API fs: convert fs shrinkers to new scan/count API xfs: fix dquot isolation hang xfs-convert-dquot-cache-lru-to-list_lru-fix xfs: convert dquot cache lru to list_lru xfs: rework buffer dispose list tracking xfs-convert-buftarg-lru-to-generic-code-fix xfs: convert buftarg LRU to generic code fs: convert inode and dentry shrinking to be node aware vmscan: per-node deferred work ...
2013-09-12Merge tag 'pm+acpi-fixes-3.12-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: "All of these commits are fixes that have emerged recently and some of them fix bugs introduced during this merge window. Specifics: 1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events After the recent ACPIPHP changes we've seen some interesting breakage on a system that triggers device check notifications during boot for non-existing devices. Although those notifications are really spurious, we should be able to deal with them nevertheless and that shouldn't introduce too much overhead. Four commits to make that work properly. 2) Memory hotplug and hibernation mutual exclusion rework This was maent to be a cleanup, but it happens to fix a classical ABBA deadlock between system suspend/hibernation and ACPI memory hotplug which is possible if they are started roughly at the same time. Three commits rework memory hotplug so that it doesn't acquire pm_mutex and make hibernation use device_hotplug_lock which prevents it from racing with memory hotplug. 3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix The ACPI LPSS driver crashes during boot on Apple Macbook Air with Haswell that has slightly unusual BIOS configuration in which one of the LPSS device's _CRS method doesn't return all of the information expected by the driver. Fix from Mika Westerberg, for stable. 4) ACPICA fix related to Store->ArgX operation AML interpreter fix for obscure breakage that causes AML to be executed incorrectly on some machines (observed in practice). From Bob Moore. 5) ACPI core fix for PCI ACPI device objects lookup There still are cases in which there is more than one ACPI device object matching a given PCI device and we don't choose the one that the BIOS expects us to choose, so this makes the lookup take more criteria into account in those cases. 6) Fix to prevent cpuidle from crashing in some rare cases If the result of cpuidle_get_driver() is NULL, which can happen on some systems, cpuidle_driver_ref() will crash trying to use that pointer and the Daniel Fu's fix prevents that from happening. 7) cpufreq fixes related to CPU hotplug Stephen Boyd reported a number of concurrency problems with cpufreq related to CPU hotplug which are addressed by a series of fixes from Srivatsa S Bhat and Viresh Kumar. 8) cpufreq fix for time conversion in time_in_state attribute Time conversion carried out by cpufreq when user space attempts to read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state won't work correcty if cputime_t doesn't map directly to jiffies. Fix from Andreas Schwab. 9) Revert of a troublesome cpufreq commit Commit 7c30ed5 (cpufreq: make sure frequency transitions are serialized) was intended to address some known concurrency problems in cpufreq related to the ordering of transitions, but unfortunately it introduced several problems of its own, so I decided to revert it now and address the original problems later in a more robust way. 10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle. 11) cpufreq fixes related to system suspend/resume The recent cpufreq changes that made it preserve CPU sysfs attributes over suspend/resume cycles introduced a possible NULL pointer dereference that caused it to crash during the second attempt to suspend. Three commits from Srivatsa S Bhat fix that problem and a couple of related issues. 12) cpufreq locking fix cpufreq_policy_restore() should acquire the lock for reading, but it acquires it for writing. Fix from Lan Tianyu" * tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits) cpufreq: Acquire the lock in cpufreq_policy_restore() for reading cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu cpufreq: Restructure if/else block to avoid unintended behavior cpufreq: Fix crash in cpufreq-stats during suspend/resume intel_pstate: Add Haswell CPU models Revert "cpufreq: make sure frequency transitions are serialized" cpufreq: Use signed type for 'ret' variable, to store negative error values cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock cpufreq: Split __cpufreq_remove_dev() into two parts cpufreq: Fix wrong time unit conversion cpufreq: serialize calls to __cpufreq_governor() cpufreq: don't allow governor limits to be changed when it is disabled ACPI / bind: Prefer device objects with _STA to those without it ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks ACPI / hotplug / PCI: Use _OST to notify firmware about notify status ACPI / hotplug / PCI: Avoid doing too much for spurious notifies ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field. ACPI / hotplug / PCI: Don't trim devices before scanning the namespace ...
2013-09-11initmpfs: make rootfs use tmpfs when CONFIG_TMPFS enabledRob Landley
Conditionally call the appropriate fs_init function and fill_super functions. Add a use once guard to shmem_init() to simply succeed on a second call. (Note that IS_ENABLED() is a compile time constant so dead code elimination removes unused function calls when CONFIG_TMPFS is disabled.) Signed-off-by: Rob Landley <rob@landley.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Warren <swarren@nvidia.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>