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 have also verified your test code on my machine, but can not find
this message.
> ----------
> [ 621.747994] vmtoolsd invoked oom-killer: gfp_mask=0x14200ca(GFP_HIGHUSER_MOVABLE), nodemask=(null), order=0, oom_score_adj=0
> [ 621.751357] vmtoolsd cpuset=/ mems_allowed=0
> [ 621.753124] CPU: 1 PID: 684 Comm: vmtoolsd Not tainted 4.14.0-next-20171124+ #681
> [ 621.755392] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
> [ 621.758535] Call Trace:
> [ 621.760324] dump_stack+0x5f/0x86
> [ 621.761981] dump_header+0x69/0x431
> [ 621.763459] ? trace_hardirqs_on_caller+0xe7/0x180
> [ 621.765200] oom_kill_process+0x294/0x670
> [ 621.766800] out_of_memory+0x423/0x5c0
> [ 621.768432] __alloc_pages_nodemask+0x11e2/0x1450
> [ 621.770135] filemap_fault+0x4b7/0x710
> [ 621.771656] __xfs_filemap_fault.constprop.0+0x68/0x210
> [ 621.773463] __do_fault+0x15/0xc0
> [ 621.775252] __handle_mm_fault+0xd7c/0x1390
> [ 621.777204] ? __audit_syscall_exit+0x195/0x290
> [ 621.779318] handle_mm_fault+0x173/0x330
> [ 621.781047] __do_page_fault+0x2a7/0x510
> [ 621.784331] do_page_fault+0x2c/0x2f0
> [ 621.786126] page_fault+0x22/0x30
> [ 621.787581] RIP: 0033:0x7f397f268dd0
> [ 621.789102] RSP: 002b:00007fffa8b225f8 EFLAGS: 00010202
> [ 621.790842] RAX: 00005635d5c715b0 RBX: 0000000000000001 RCX: 0000000000000001
> [ 621.793421] RDX: 0000000000000001 RSI: 00007f3981f16350 RDI: 00005635d5c715b0
> [ 621.795610] RBP: 00005635d5c715b0 R08: 0000000000000000 R09: 0000000000000004
> [ 621.797732] R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
> [ 621.800252] R13: 00007f3981f16350 R14: 0000000000000000 R15: 0000000000000000
> [ 621.802406] Mem-Info:
> [ 621.803682] active_anon:881485 inactive_anon:2093 isolated_anon:0
> active_file:54 inactive_file:468 isolated_file:0
> unevictable:0 dirty:13 writeback:0 unstable:0
> slab_reclaimable:6684 slab_unreclaimable:16061
> mapped:626 shmem:2165 pagetables:3418 bounce:0
> free:21384 free_pcp:74 free_cma:0
> [ 621.814512] Node 0 active_anon:3525940kB inactive_anon:8372kB active_file:216kB inactive_file:1872kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:2504kB dirty:52kB writeback:0kB shmem:8660kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 636928kB writeback_tmp:0kB unstable:0kB all_unreclaimable? yes
> [ 621.821534] Node 0 DMA free:14848kB min:284kB low:352kB high:420kB active_anon:992kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15988kB managed:15904kB mlocked:0kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [ 621.829035] lowmem_reserve[]: 0 2687 3645 3645
> [ 621.831655] Node 0 DMA32 free:53004kB min:49608kB low:62008kB high:74408kB active_anon:2712648kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129216kB managed:2773132kB mlocked:0kB kernel_stack:96kB pagetables:5096kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [ 621.839945] lowmem_reserve[]: 0 0 958 958
> [ 621.842811] Node 0 Normal free:17140kB min:17684kB low:22104kB high:26524kB active_anon:812300kB inactive_anon:8372kB active_file:1228kB inactive_file:1868kB unevictable:0kB writepending:52kB present:1048576kB managed:981224kB mlocked:0kB kernel_stack:3520kB pagetables:8552kB bounce:0kB free_pcp:120kB local_pcp:120kB free_cma:0kB
> [ 621.852473] lowmem_reserve[]: 0 0 0 0
> [ 621.854094] Node 0 DMA: 2*4kB (M) 1*8kB (M) 1*16kB (M) 1*32kB (U) 1*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 2*1024kB (UM) 0*2048kB 3*4096kB (ME) = 14848kB
> [ 621.857755] Node 0 DMA32: 65*4kB (UM) 5*8kB (UME) 118*16kB (UME) 66*32kB (UME) 25*64kB (UME) 12*128kB (UE) 8*256kB (UE) 3*512kB (ME) 5*1024kB (E) 10*2048kB (E) 4*4096kB (ME) = 53004kB
> [ 621.864205] Node 0 Normal: 619*4kB (UME) 506*8kB (UME) 207*16kB (UME) 121*32kB (UME) 33*64kB (UME) 7*128kB (ME) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 16972kB
> [ 621.869661] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
> [ 621.872283] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
> [ 621.875600] 2823 total pagecache pages
> [ 621.878108] 0 pages in swap cache
> [ 621.879818] Swap cache stats: add 0, delete 0, find 0/0
> [ 621.864205] Node 0 Normal: 619*4kB (UME) 506*8kB (UME) 207*16kB (UME) 121*32kB (UME) 33*64kB (UME) 7*128kB (ME) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 16972kB
> [ 621.869661] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
> [ 621.872283] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
> [ 621.875600] 2823 total pagecache pages
> [ 621.878108] 0 pages in swap cache
> [ 621.879818] Swap cache stats: add 0, delete 0, find 0/0
> [ 621.881796] Free swap = 0kB
> [ 621.883389] Total swap = 0kB
> [ 621.884940] 1048445 pages RAM
> [ 621.886442] 0 pages HighMem/MovableOnly
> [ 621.888197] 105880 pages reserved
> [ 621.889964] 0 pages hwpoisoned
> [ 621.891477] Out of memory: Kill process 8459 (a.out) score 999 or sacrifice child
> [ 621.894363] Killed process 8459 (a.out) total-vm:4180kB, anon-rss:88kB, file-rss:0kB, shmem-rss:0kB
> [ 621.897172] oom_reaper: reaped process 8459 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 622.424664] vm direct limit must be set greater than background limit.
> [ 622.427810] vm direct limit must be set greater than background limit.
> [ 622.631937] vm direct limit must be set greater than background limit.
> [ 622.634316] vm direct limit must be set greater than background limit.
> [ 622.789310] a.out invoked oom-killer: gfp_mask=0x14280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=(null), order=0, oom_score_adj=0
> [ 622.792603] a.out cpuset=/ mems_allowed=0
> [ 622.794797] CPU: 2 PID: 8455 Comm: a.out Not tainted 4.14.0-next-20171124+ #681
> [ 622.797307] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/02/2015
> [ 622.800901] Call Trace:
> [ 622.802264] dump_stack+0x5f/0x86
> [ 622.803733] dump_header+0x69/0x431
> [ 622.805198] ? trace_hardirqs_on_caller+0xe7/0x180
> [ 622.807001] oom_kill_process+0x294/0x670
> [ 622.808655] out_of_memory+0x423/0x5c0
> [ 622.810771] __alloc_pages_nodemask+0x11e2/0x1450
> [ 622.812632] ? __lock_acquire+0x306/0x1420
> [ 622.814315] alloc_pages_vma+0x7b/0x1e0
> [ 622.816091] __handle_mm_fault+0x1001/0x1390
> [ 622.817754] ? retint_kernel+0x2d/0x2d
> [ 622.819785] handle_mm_fault+0x173/0x330
> [ 622.821331] __do_page_fault+0x2a7/0x510
> [ 622.822886] do_page_fault+0x2c/0x2f0
> [ 622.824307] page_fault+0x22/0x30
> [ 622.828293] RIP: 0033:0x4006f0
> [ 622.829930] RSP: 002b:00007fffa638c440 EFLAGS: 00010206
> [ 622.831701] RAX: 00000000d380e000 RBX: 0000000100000000 RCX: 00007f9ed5110190
> [ 622.834199] RDX: 0000000000000000 RSI: 00007fffa638c260 RDI: 00007fffa638c260
> [ 622.836253] RBP: 00007f9cd5245010 R08: 00007fffa638c370 R09: 00007fffa638c1b0
> [ 622.838271] R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000006
> [ 622.840430] R13: 00007f9cd5245010 R14: 0000000000000000 R15: 0000000000000000
> [ 622.854308] Mem-Info:
> [ 622.855493] active_anon:881658 inactive_anon:2093 isolated_anon:0
> active_file:1 inactive_file:120 isolated_file:0
> unevictable:0 dirty:3 writeback:0 unstable:0
> slab_reclaimable:6676 slab_unreclaimable:16057
> mapped:585 shmem:2165 pagetables:3412 bounce:0
> free:21273 free_pcp:124 free_cma:0
> [ 622.867896] Node 0 active_anon:3526676kB inactive_anon:8372kB active_file:8kB inactive_file:828kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:2344kB dirty:20kB writeback:0kB shmem:8660kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 636928kB writeback_tmp:0kB unstable:0kB all_unreclaimable? yes
> [ 622.875151] Node 0 DMA free:14848kB min:284kB low:352kB high:420kB active_anon:992kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15988kB managed:15904kB mlocked:0kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [ 622.882244] lowmem_reserve[]: 0 2687 3645 3645
> [ 622.883861] Node 0 DMA32 free:53004kB min:49608kB low:62008kB high:74408kB active_anon:2712648kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129216kB managed:2773132kB mlocked:0kB kernel_stack:96kB pagetables:5096kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
> [ 622.891029] lowmem_reserve[]: 0 0 958 958
> [ 622.892814] Node 0 Normal free:18000kB min:17684kB low:22104kB high:26524kB active_anon:813036kB inactive_anon:8372kB active_file:8kB inactive_file:1300kB unevictable:0kB writepending:20kB present:1048576kB managed:981224kB mlocked:0kB kernel_stack:3488kB pagetables:8532kB bounce:0kB free_pcp:120kB local_pcp:0kB free_cma:0kB
> [ 622.901963] lowmem_reserve[]: 0 0 0 0
> [ 622.903501] Node 0 DMA: 2*4kB (M) 1*8kB (M) 1*16kB (M) 1*32kB (U) 1*64kB (U) 1*128kB (U) 1*256kB (U) 0*512kB 2*1024kB (UM) 0*2048kB 3*4096kB (ME) = 14848kB
> [ 622.907115] Node 0 DMA32: 65*4kB (UM) 5*8kB (UME) 118*16kB (UME) 66*32kB (UME) 25*64kB (UME) 12*128kB (UE) 8*256kB (UE) 3*512kB (ME) 5*1024kB (E) 10*2048kB (E) 4*4096kB (ME) = 53004kB
> [ 622.912651] Node 0 Normal: 823*4kB (UME) 505*8kB (UME) 214*16kB (UME) 127*32kB (UME) 33*64kB (UME) 7*128kB (ME) 1*256kB (M) 0*512kB 0*1024kB 0*2048kB 0*4096kB = 18084kB
> [ 622.917512] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
> [ 622.920171] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
> [ 622.922742] 2503 total pagecache pages
> [ 622.924417] 0 pages in swap cache
> [ 622.928889] Swap cache stats: add 0, delete 0, find 0/0
> [ 622.931040] Free swap = 0kB
> [ 622.932560] Total swap = 0kB
> [ 622.934031] 1048445 pages RAM
> [ 622.935503] 0 pages HighMem/MovableOnly
> [ 622.937440] 105880 pages reserved
> [ 622.939066] 0 pages hwpoisoned
> [ 622.940578] Out of memory: Kill process 8460 (a.out) score 999 or sacrifice child
> [ 622.943093] Killed process 8460 (a.out) total-vm:4180kB, anon-rss:88kB, file-rss:0kB, shmem-rss:0kB
> [ 622.946331] oom_reaper: reaped process 8460 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> ----------
>
> ----------
> #include <stdio.h>
> #include <stdlib.h>
> #include <unistd.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
>
> int main(int argc, char *argv[])
> {
> static char buffer[4096] = { };
> char *buf = NULL;
> unsigned long size;
> unsigned long i;
> for (i = 0; i < 16; i++) {
> if (fork() == 0) {
> int fd = open("/proc/self/oom_score_adj", O_WRONLY);
> write(fd, "1000", 4);
> close(fd);
> snprintf(buffer, sizeof(buffer), "/tmp/file.%u", getpid());
> fd = open(buffer, O_WRONLY | O_CREAT | O_APPEND, 0600);
> sleep(1);
> while (write(fd, buffer, sizeof(buffer)) == sizeof(buffer));
> _exit(0);
> }
> }
> for (size = 1048576; size < 512UL * (1 << 30); size <<= 1) {
> char *cp = realloc(buf, size);
> if (!cp) {
> size >>= 1;
> break;
> }
> buf = cp;
> }
> sleep(2);
> /* Will cause OOM due to overcommit */
> for (i = 0; i < size; i += 4096)
> buf[i] = 0;
> return 0;
> }
> ----------
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