Re: [PATCH] mm: print a warning once the vm dirtiness settings is illogical

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



2017-11-26 10:42 GMT+08:00 Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>:
> 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
> ----------
>

Then under these settings the message should not been printed.

>>
>> I have also verified your test code on my machine, but can not find
>> this message.
>>
>
> Not always printed. It is timing dependent.
>

I will try and analysis why this happen.

> ----------
> [  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.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]
  Powered by Linux