diff options
| author | David Rientjes | 2015-09-08 15:00:42 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2015-09-08 15:35:28 -0700 |
| commit | 071a4befebb655d6b31bf5c6bacd5a6df035224d (patch) | |
| tree | b57c135e68a40d48a51f2b1b126179a7121b23f6 | |
| parent | 54e9e29132d7caefcad470281cae06ac34a982c8 (diff) | |
mm, oom: do not panic for oom kills triggered from sysrq
Sysrq+f is used to kill a process either for debug or when the VM is
otherwise unresponsive.
It is not intended to trigger a panic when no process may be killed.
Avoid panicking the system for sysrq+f when no processes are killed.
Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Michal Hocko <mhocko@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | Documentation/sysrq.txt | 3 | ||||
| -rw-r--r-- | mm/oom_kill.c | 7 |
2 files changed, 7 insertions, 3 deletions
diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index 267f39386f99..13f5619b2203 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -75,7 +75,8 @@ On all - write a character to /proc/sysrq-trigger. e.g.: 'e' - Send a SIGTERM to all processes, except for init. -'f' - Will call oom_kill to kill a memory hog process. +'f' - Will call the oom killer to kill a memory hog process, but do not + panic if nothing can be killed. 'g' - Used by kgdb (kernel debugger) diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 77adc8e876aa..91dd59f63910 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -607,6 +607,9 @@ void check_panic_on_oom(struct oom_control *oc, enum oom_constraint constraint, if (constraint != CONSTRAINT_NONE) return; } + /* Do not panic for oom kills triggered by sysrq */ + if (oc->order == -1) + return; dump_header(oc, NULL, memcg); panic("Out of memory: %s panic_on_oom is enabled\n", sysctl_panic_on_oom == 2 ? "compulsory" : "system-wide"); @@ -686,11 +689,11 @@ bool out_of_memory(struct oom_control *oc) p = select_bad_process(oc, &points, totalpages); /* Found nothing?!?! Either we hang forever, or we panic. */ - if (!p) { + if (!p && oc->order != -1) { dump_header(oc, NULL, NULL); panic("Out of memory and no killable processes...\n"); } - if (p != (void *)-1UL) { + if (p && p != (void *)-1UL) { oom_kill_process(oc, p, points, totalpages, NULL, "Out of memory"); killed = 1; |