Yafang Shao wrote: > 2017-11-26 0:05 GMT+08:00 Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>: > > On 2017/09/28 18:54, Yafang Shao wrote: > >> The vm direct limit setting must be set greater than vm background > >> limit setting. > >> Otherwise we will print a warning to help the operator to figure > >> out that the vm dirtiness settings is in illogical state. > >> > >> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> > > > > I got this warning by simple OOM killer flooding. Is this what you meant? > > > > This message is only printed when the vm dirtiness settings are illogic. > Pls. get the bellow four knobs and check whether they are set proper or not. > > vm.dirty_ratio > vm.dirty_bytes > vm.dirty_background_ratio > vm.dirty_background_bytes > > If these four valuses are set properly, this message should not be > printed when OOM happens. I didn't tune vm related values. ---------- vm.admin_reserve_kbytes = 8192 vm.block_dump = 0 vm.compact_unevictable_allowed = 1 vm.dirty_background_bytes = 0 vm.dirty_background_ratio = 10 vm.dirty_bytes = 0 vm.dirty_expire_centisecs = 3000 vm.dirty_ratio = 30 vm.dirty_writeback_centisecs = 500 vm.dirtytime_expire_seconds = 43200 vm.drop_caches = 0 vm.extfrag_threshold = 500 vm.hugetlb_shm_group = 0 vm.laptop_mode = 0 vm.legacy_va_layout = 0 vm.lowmem_reserve_ratio = 256 256 32 vm.max_map_count = 65530 vm.memory_failure_early_kill = 0 vm.memory_failure_recovery = 1 vm.min_free_kbytes = 67584 vm.min_slab_ratio = 5 vm.min_unmapped_ratio = 1 vm.mmap_min_addr = 4096 vm.mmap_rnd_bits = 28 vm.mmap_rnd_compat_bits = 8 vm.nr_hugepages = 0 vm.nr_hugepages_mempolicy = 0 vm.nr_overcommit_hugepages = 0 vm.numa_stat = 1 vm.numa_zonelist_order = Node vm.oom_dump_tasks = 0 vm.oom_kill_allocating_task = 0 vm.overcommit_kbytes = 0 vm.overcommit_memory = 0 vm.overcommit_ratio = 50 vm.page-cluster = 3 vm.panic_on_oom = 0 vm.percpu_pagelist_fraction = 0 vm.stat_interval = 1 vm.swappiness = 30 vm.user_reserve_kbytes = 116665 vm.vfs_cache_pressure = 100 vm.watermark_scale_factor = 10 vm.zone_reclaim_mode = 0 ---------- > > I have also verified your test code on my machine, but can not find > this message. > Not always printed. It is timing dependent. ---------- [ 343.783160] a.out invoked oom-killer: gfp_mask=0x14200ca(GFP_HIGHUSER_MOVABLE), nodemask=(null), order=0, oom_score_adj=1000 [ 343.793554] a.out cpuset=/ mems_allowed=0 [ 343.795437] CPU: 2 PID: 2930 Comm: a.out Not tainted 4.14.0-next-20171124+ #681 [ 343.798112] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015 [ 343.801348] Call Trace: [ 343.802844] dump_stack+0x5f/0x86 [ 343.804545] dump_header+0x69/0x431 [ 343.806268] oom_kill_process+0x294/0x670 [ 343.808042] out_of_memory+0x423/0x5c0 [ 343.809701] __alloc_pages_nodemask+0x11e2/0x1450 [ 343.811553] filemap_fault+0x4b7/0x710 [ 343.813184] __xfs_filemap_fault.constprop.0+0x68/0x210 [ 343.815129] __do_fault+0x15/0xc0 [ 343.816625] __handle_mm_fault+0xd7c/0x1390 [ 343.818315] handle_mm_fault+0x173/0x330 [ 343.820051] __do_page_fault+0x2a7/0x510 [ 343.821842] do_page_fault+0x2c/0x2f0 [ 343.823376] page_fault+0x22/0x30 [ 343.824834] RIP: 0033:0x7f12886f9840 [ 343.826302] RSP: 002b:00007ffdfa961828 EFLAGS: 00010246 [ 343.828075] RAX: 0000000000001000 RBX: 0000000000000003 RCX: 00007f12886f9840 [ 343.830324] RDX: 0000000000001000 RSI: 00000000006010a0 RDI: 0000000000000003 [ 343.832526] RBP: 0000000000000000 R08: 00007ffdfa961760 R09: 00007ffdfa9615a0 [ 343.834693] R10: 0000000000000008 R11: 0000000000000246 R12: 000000000040079d [ 343.836825] R13: 00007ffdfa961930 R14: 0000000000000000 R15: 0000000000000000 [ 343.839058] Mem-Info: [ 343.840557] active_anon:882238 inactive_anon:2091 isolated_anon:0 [ 343.840557] active_file:27 inactive_file:0 isolated_file:0 [ 343.840557] unevictable:0 dirty:2 writeback:0 unstable:0 [ 343.840557] slab_reclaimable:6412 slab_unreclaimable:15971 [ 343.840557] mapped:695 shmem:2162 pagetables:3290 bounce:0 [ 343.840557] free:21394 free_pcp:1 free_cma:0 [ 343.851466] Node 0 active_anon:3528952kB inactive_anon:8364kB active_file:108kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:2780kB dirty:8kB writeback:0kB shmem:8648kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 2797568kB writeback_tmp:0kB unstable:0kB all_unreclaimable? yes [ 343.859073] Node 0 DMA free:14944kB min:284kB low:352kB high:420kB active_anon:928kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15988kB managed:15904kB mlocked:0kB kernel_stack:0kB pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB [ 343.866543] lowmem_reserve[]: 0 2708 3666 3666 [ 343.868345] Node 0 DMA32 free:53196kB min:49608kB low:62008kB high:74408kB active_anon:2713592kB inactive_anon:0kB active_file:100kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129216kB managed:2773132kB mlocked:0kB kernel_stack:16kB pagetables:3372kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB [ 343.877512] lowmem_reserve[]: 0 0 958 958 [ 343.878700] vm direct limit must be set greater than background limit. [ 343.878706] vm direct limit must be set greater than background limit. [ 343.878712] vm direct limit must be set greater than background limit. [ 343.878718] vm direct limit must be set greater than background limit. [ 343.878723] vm direct limit must be set greater than background limit. [ 343.878728] vm direct limit must be set greater than background limit. [ 343.878734] vm direct limit must be set greater than background limit. [ 343.878739] vm direct limit must be set greater than background limit. [ 343.878744] vm direct limit must be set greater than background limit. [ 343.878749] vm direct limit must be set greater than background limit. [ 343.878755] vm direct limit must be set greater than background limit. [ 343.878760] vm direct limit must be set greater than background limit. [ 343.878767] vm direct limit must be set greater than background limit. [ 343.878772] vm direct limit must be set greater than background limit. [ 343.878777] vm direct limit must be set greater than background limit. [ 343.878782] vm direct limit must be set greater than background limit. [ 343.878786] vm direct limit must be set greater than background limit. [ 343.878791] vm direct limit must be set greater than background limit. [ 343.878796] vm direct limit must be set greater than background limit. [ 343.878800] vm direct limit must be set greater than background limit. [ 343.878805] vm direct limit must be set greater than background limit. [ 343.878809] vm direct limit must be set greater than background limit. [ 343.878814] vm direct limit must be set greater than background limit. [ 343.878818] vm direct limit must be set greater than background limit. [ 343.878826] vm direct limit must be set greater than background limit. [ 343.878831] vm direct limit must be set greater than background limit. [ 343.878835] vm direct limit must be set greater than background limit. [ 343.878840] vm direct limit must be set greater than background limit. [ 343.878844] vm direct limit must be set greater than background limit. [ 343.878848] vm direct limit must be set greater than background limit. [ 343.878852] vm direct limit must be set greater than background limit. [ 343.878856] vm direct limit must be set greater than background limit. [ 343.878861] vm direct limit must be set greater than background limit. [ 343.878865] vm direct limit must be set greater than background limit. [ 343.878891] vm direct limit must be set greater than background limit. [ 343.878897] vm direct limit must be set greater than background limit. [ 343.878898] vm direct limit must be set greater than background limit. [ 343.878915] vm direct limit must be set greater than background limit. [ 343.956240] Node 0 Normal free:17796kB min:17684kB low:22104kB high:26524kB active_anon:815300kB inactive_anon:8364kB active_file:0kB inactive_file:4kB unevictable:0kB writepending:0kB present:1048576kB managed:981224kB mlocked:0kB kernel_stack:3632kB pagetables:9792kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB [ 343.963339] lowmem_reserve[]: 0 0 0 0 [ 343.964644] Node 0 DMA: 0*4kB 0*8kB 0*16kB 1*32kB (M) 3*64kB (UM) 1*128kB (U) 1*256kB (U) 0*512kB 2*1024kB (UM) 0*2048kB 3*4096kB (ME) = 14944kB [ 343.968026] Node 0 DMA32: 12*4kB (UM) 15*8kB (UM) 28*16kB (UM) 28*32kB (UM) 12*64kB (UM) 21*128kB (UM) 14*256kB (UM) 12*512kB (UM) 24*1024kB (UM) 5*2048kB (E) 1*4096kB (E) = 53608kB [ 343.972148] Node 0 Normal: 513*4kB (UME) 282*8kB (UME) 215*16kB (UME) 128*32kB (UME) 41*64kB (UME) 12*128kB (UME) 3*256kB (M) 2*512kB (M) 0*1024kB 0*2048kB 0*4096kB = 17796kB [ 343.976695] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB [ 343.979084] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [ 343.981469] 2290 total pagecache pages [ 343.982709] 0 pages in swap cache [ 343.983989] Swap cache stats: add 0, delete 0, find 0/0 [ 343.987118] Free swap = 0kB [ 343.988182] Total swap = 0kB [ 343.990799] 1048445 pages RAM [ 343.991844] 0 pages HighMem/MovableOnly [ 343.994723] 105880 pages reserved [ 343.995878] 0 pages hwpoisoned [ 343.998745] Out of memory: Kill process 2929 (a.out) score 999 or sacrifice child [ 344.002681] Killed process 2929 (a.out) total-vm:4180kB, anon-rss:88kB, file-rss:0kB, shmem-rss:0kB ---------- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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