On Fri 01-02-19 12:36:04, Tetsuo Handa wrote:
> ----------
> #include <stdio.h>
> #include <string.h>
> #include <unistd.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> #include <fcntl.h>
>
> int main(int argc, char *argv[])
> {
> static char buffer[10485760];
> static int pipe_fd[2] = { EOF, EOF };
> unsigned int i;
> int fd;
> char buf[64] = { };
> if (pipe(pipe_fd))
> return 1;
> if (chdir("/sys/fs/cgroup/"))
> return 1;
> fd = open("cgroup.subtree_control", O_WRONLY);
> write(fd, "+memory", 7);
> close(fd);
> mkdir("test1", 0755);
> fd = open("test1/memory.oom.group", O_WRONLY);
> write(fd, "1", 1);
> close(fd);
> fd = open("test1/cgroup.procs", O_WRONLY);
> write(fd, "1", 1);
> snprintf(buf, sizeof(buf) - 1, "%d", getpid());
> write(fd, buf, strlen(buf));
> close(fd);
> snprintf(buf, sizeof(buf) - 1, "%lu", sizeof(buffer) * 5);
> fd = open("test1/memory.max", O_WRONLY);
> write(fd, buf, strlen(buf));
> close(fd);
> for (i = 0; i < 10; i++)
> if (fork() == 0) {
> char c;
> close(pipe_fd[1]);
> read(pipe_fd[0], &c, 1);
> memset(buffer, 0, sizeof(buffer));
> sleep(3);
> _exit(0);
> }
> close(pipe_fd[0]);
> close(pipe_fd[1]);
> sleep(3);
> return 0;
> }
> ----------
>
> ----------
> [ 37.052923][ T9185] a.out invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), order=0, oom_score_adj=0
> [ 37.056169][ T9185] CPU: 4 PID: 9185 Comm: a.out Kdump: loaded Not tainted 5.0.0-rc4-next-20190131 #280
> [ 37.059205][ T9185] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
> [ 37.062954][ T9185] Call Trace:
> [ 37.063976][ T9185] dump_stack+0x67/0x95
> [ 37.065263][ T9185] dump_header+0x51/0x570
> [ 37.066619][ T9185] ? trace_hardirqs_on+0x3f/0x110
> [ 37.068171][ T9185] ? _raw_spin_unlock_irqrestore+0x3d/0x70
> [ 37.069967][ T9185] oom_kill_process+0x18d/0x210
> [ 37.071515][ T9185] out_of_memory+0x11b/0x380
> [ 37.072936][ T9185] mem_cgroup_out_of_memory+0xb6/0xd0
> [ 37.074601][ T9185] try_charge+0x790/0x820
> [ 37.076021][ T9185] mem_cgroup_try_charge+0x42/0x1d0
> [ 37.077629][ T9185] mem_cgroup_try_charge_delay+0x11/0x30
> [ 37.079370][ T9185] do_anonymous_page+0x105/0x5e0
> [ 37.080939][ T9185] __handle_mm_fault+0x9cb/0x1070
> [ 37.082485][ T9185] handle_mm_fault+0x1b2/0x3a0
> [ 37.083819][ T9185] ? handle_mm_fault+0x47/0x3a0
> [ 37.085181][ T9185] __do_page_fault+0x255/0x4c0
> [ 37.086529][ T9185] do_page_fault+0x28/0x260
> [ 37.087788][ T9185] ? page_fault+0x8/0x30
> [ 37.088978][ T9185] page_fault+0x1e/0x30
> [ 37.090142][ T9185] RIP: 0033:0x7f8b183aefe0
> [ 37.091433][ T9185] Code: 20 f3 44 0f 7f 44 17 d0 f3 44 0f 7f 47 30 f3 44 0f 7f 44 17 c0 48 01 fa 48 83 e2 c0 48 39 d1 74 a3 66 0f 1f 84 00 00 00 00 00 <66> 44 0f 7f 01 66 44 0f 7f 41 10 66 44 0f 7f 41 20 66 44 0f 7f 41
> [ 37.096917][ T9185] RSP: 002b:00007fffc5d329e8 EFLAGS: 00010206
> [ 37.098615][ T9185] RAX: 00000000006010e0 RBX: 0000000000000008 RCX: 0000000000c30000
> [ 37.100905][ T9185] RDX: 00000000010010c0 RSI: 0000000000000000 RDI: 00000000006010e0
> [ 37.103349][ T9185] RBP: 0000000000000000 R08: 00007f8b188f4740 R09: 0000000000000000
> [ 37.105797][ T9185] R10: 00007fffc5d32420 R11: 00007f8b183aef40 R12: 0000000000000005
> [ 37.108228][ T9185] R13: 0000000000000000 R14: ffffffffffffffff R15: 0000000000000000
> [ 37.110840][ T9185] memory: usage 51200kB, limit 51200kB, failcnt 125
> [ 37.113045][ T9185] memory+swap: usage 0kB, limit 9007199254740988kB, failcnt 0
> [ 37.115808][ T9185] kmem: usage 0kB, limit 9007199254740988kB, failcnt 0
> [ 37.117660][ T9185] Memory cgroup stats for /test1: cache:0KB rss:49484KB rss_huge:30720KB shmem:0KB mapped_file:0KB dirty:0KB writeback:0KB inactive_anon:0KB active_anon:49700KB inactive_file:0KB active_file:0KB unevictable:0KB
> [ 37.123371][ T9185] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,oom_memcg=/test1,task_memcg=/test1,task=a.out,pid=9188,uid=0
> [ 37.128158][ T9185] Memory cgroup out of memory: Killed process 9188 (a.out) total-vm:14456kB, anon-rss:10324kB, file-rss:504kB, shmem-rss:0kB
> [ 37.132710][ T9185] Tasks in /test1 are going to be killed due to memory.oom.group set
> [ 37.132833][ T54] oom_reaper: reaped process 9188 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.135498][ T9185] Memory cgroup out of memory: Killed process 1 (systemd) total-vm:43400kB, anon-rss:1228kB, file-rss:3992kB, shmem-rss:0kB
> [ 37.143434][ T9185] Memory cgroup out of memory: Killed process 9182 (a.out) total-vm:14456kB, anon-rss:76kB, file-rss:588kB, shmem-rss:0kB
> [ 37.144328][ T54] oom_reaper: reaped process 1 (systemd), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.147585][ T9185] Memory cgroup out of memory: Killed process 9183 (a.out) total-vm:14456kB, anon-rss:6228kB, file-rss:512kB, shmem-rss:0kB
> [ 37.157222][ T9185] Memory cgroup out of memory: Killed process 9184 (a.out) total-vm:14456kB, anon-rss:6228kB, file-rss:508kB, shmem-rss:0kB
> [ 37.157259][ T9185] Memory cgroup out of memory: Killed process 9185 (a.out) total-vm:14456kB, anon-rss:6228kB, file-rss:512kB, shmem-rss:0kB
> [ 37.157291][ T9185] Memory cgroup out of memory: Killed process 9186 (a.out) total-vm:14456kB, anon-rss:4180kB, file-rss:508kB, shmem-rss:0kB
> [ 37.157306][ T54] oom_reaper: reaped process 9183 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.157328][ T9185] Memory cgroup out of memory: Killed process 9187 (a.out) total-vm:14456kB, anon-rss:4180kB, file-rss:512kB, shmem-rss:0kB
> [ 37.157452][ T9185] Memory cgroup out of memory: Killed process 9189 (a.out) total-vm:14456kB, anon-rss:6228kB, file-rss:512kB, shmem-rss:0kB
> [ 37.158733][ T9185] Memory cgroup out of memory: Killed process 9190 (a.out) total-vm:14456kB, anon-rss:552kB, file-rss:512kB, shmem-rss:0kB
> [ 37.160083][ T54] oom_reaper: reaped process 9186 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.160187][ T54] oom_reaper: reaped process 9189 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.206941][ T54] oom_reaper: reaped process 9185 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.212300][ T9185] Memory cgroup out of memory: Killed process 9191 (a.out) total-vm:14456kB, anon-rss:4180kB, file-rss:512kB, shmem-rss:0kB
> [ 37.212317][ T54] oom_reaper: reaped process 9190 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.218860][ T9185] Memory cgroup out of memory: Killed process 9192 (a.out) total-vm:14456kB, anon-rss:1080kB, file-rss:512kB, shmem-rss:0kB
> [ 37.227667][ T54] oom_reaper: reaped process 9192 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> [ 37.292323][ T9193] abrt-hook-ccpp (9193) used greatest stack depth: 10480 bytes left
> [ 37.351843][ T1] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000008b
> [ 37.354833][ T1] CPU: 7 PID: 1 Comm: systemd Kdump: loaded Not tainted 5.0.0-rc4-next-20190131 #280
> [ 37.357876][ T1] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 04/13/2018
> [ 37.361685][ T1] Call Trace:
> [ 37.363239][ T1] dump_stack+0x67/0x95
> [ 37.365010][ T1] panic+0xfc/0x2b0
> [ 37.366853][ T1] do_exit+0xd55/0xd60
> [ 37.368595][ T1] do_group_exit+0x47/0xc0
> [ 37.370415][ T1] get_signal+0x32a/0x920
> [ 37.372449][ T1] ? _raw_spin_unlock_irqrestore+0x3d/0x70
> [ 37.374596][ T1] do_signal+0x32/0x6e0
> [ 37.376430][ T1] ? exit_to_usermode_loop+0x26/0x9b
> [ 37.378418][ T1] ? prepare_exit_to_usermode+0xa8/0xd0
> [ 37.380571][ T1] exit_to_usermode_loop+0x3e/0x9b
> [ 37.382588][ T1] prepare_exit_to_usermode+0xa8/0xd0
> [ 37.384594][ T1] ? page_fault+0x8/0x30
> [ 37.386453][ T1] retint_user+0x8/0x18
> [ 37.388160][ T1] RIP: 0033:0x7f42c06974a8
> [ 37.389922][ T1] Code: Bad RIP value.
> [ 37.391788][ T1] RSP: 002b:00007ffc3effd388 EFLAGS: 00010213
> [ 37.394075][ T1] RAX: 000000000000000e RBX: 00007ffc3effd390 RCX: 0000000000000000
> [ 37.396963][ T1] RDX: 000000000000002a RSI: 00007ffc3effd390 RDI: 0000000000000004
> [ 37.399550][ T1] RBP: 00007ffc3effd680 R08: 0000000000000000 R09: 0000000000000000
> [ 37.402334][ T1] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000001
> [ 37.404890][ T1] R13: ffffffffffffffff R14: 0000000000000884 R15: 000056460b1ac3b0
> ----------
>
> >From 83108ee95816800840ccc68c3a52fb000b572370 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Date: Fri, 1 Feb 2019 11:41:38 +0900
> Subject: [PATCH] mm,oom: Don't kill global init via memory.oom.group
>
> Since setting global init process to some memory cgroup is
> technically possible, oom_kill_memcg_member() must check it.
>
> Tasks in /test1 are going to be killed due to memory.oom.group set
> Memory cgroup out of memory: Killed process 1 (systemd) total-vm:43400kB, anon-rss:1228kB, file-rss:3992kB, shmem-rss:0kB
> oom_reaper: reaped process 1 (systemd), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000008b
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Fixes: 3d8b38eb81cac813 ("mm, oom: introduce memory.oom.group")
> Cc: Roman Gushchin <guro@xxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Thanks!
> ---
> mm/oom_kill.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index f0e8cd9..f8603c0 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -928,7 +928,8 @@ static void __oom_kill_process(struct task_struct *victim)
> */
> static int oom_kill_memcg_member(struct task_struct *task, void *unused)
> {
> - if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
> + if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN &&
> + !is_global_init(task)) {
> get_task_struct(task);
> __oom_kill_process(task);
> }
> --
> 1.8.3.1
--
Michal Hocko
SUSE Labs
