mm/oom_kill.c: introduce is_sysrq_oom helper

Introduce is_sysrq_oom helper function indicating oom kill triggered
by sysrq to improve readability.

No functional changes.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Yaowei Bai 2015-11-06 16:28:06 -08:00 committed by Linus Torvalds
parent 5bc23a0cde
commit db2a0dd7a4
1 changed files with 13 additions and 4 deletions

View File

@ -118,6 +118,15 @@ struct task_struct *find_lock_task_mm(struct task_struct *p)
return t; return t;
} }
/*
* order == -1 means the oom kill is required by sysrq, otherwise only
* for display purposes.
*/
static inline bool is_sysrq_oom(struct oom_control *oc)
{
return oc->order == -1;
}
/* return true if the task is not adequate as candidate victim task. */ /* return true if the task is not adequate as candidate victim task. */
static bool oom_unkillable_task(struct task_struct *p, static bool oom_unkillable_task(struct task_struct *p,
struct mem_cgroup *memcg, const nodemask_t *nodemask) struct mem_cgroup *memcg, const nodemask_t *nodemask)
@ -265,7 +274,7 @@ enum oom_scan_t oom_scan_process_thread(struct oom_control *oc,
* Don't allow any other task to have access to the reserves. * Don't allow any other task to have access to the reserves.
*/ */
if (test_tsk_thread_flag(task, TIF_MEMDIE)) { if (test_tsk_thread_flag(task, TIF_MEMDIE)) {
if (oc->order != -1) if (!is_sysrq_oom(oc))
return OOM_SCAN_ABORT; return OOM_SCAN_ABORT;
} }
if (!task->mm) if (!task->mm)
@ -278,7 +287,7 @@ enum oom_scan_t oom_scan_process_thread(struct oom_control *oc,
if (oom_task_origin(task)) if (oom_task_origin(task))
return OOM_SCAN_SELECT; return OOM_SCAN_SELECT;
if (task_will_free_mem(task) && oc->order != -1) if (task_will_free_mem(task) && !is_sysrq_oom(oc))
return OOM_SCAN_ABORT; return OOM_SCAN_ABORT;
return OOM_SCAN_OK; return OOM_SCAN_OK;
@ -629,7 +638,7 @@ void check_panic_on_oom(struct oom_control *oc, enum oom_constraint constraint,
return; return;
} }
/* Do not panic for oom kills triggered by sysrq */ /* Do not panic for oom kills triggered by sysrq */
if (oc->order == -1) if (is_sysrq_oom(oc))
return; return;
dump_header(oc, NULL, memcg); dump_header(oc, NULL, memcg);
panic("Out of memory: %s panic_on_oom is enabled\n", panic("Out of memory: %s panic_on_oom is enabled\n",
@ -709,7 +718,7 @@ bool out_of_memory(struct oom_control *oc)
p = select_bad_process(oc, &points, totalpages); p = select_bad_process(oc, &points, totalpages);
/* Found nothing?!?! Either we hang forever, or we panic. */ /* Found nothing?!?! Either we hang forever, or we panic. */
if (!p && oc->order != -1) { if (!p && !is_sysrq_oom(oc)) {
dump_header(oc, NULL, NULL); dump_header(oc, NULL, NULL);
panic("Out of memory and no killable processes...\n"); panic("Out of memory and no killable processes...\n");
} }