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-rw-r--r--mm/oom_kill.c34
1 files changed, 31 insertions, 3 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 942861bf9177..31bd0c344fa7 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -82,6 +82,24 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk,
#endif /* CONFIG_NUMA */
/*
+ * If this is a system OOM (not a memcg OOM) and the task selected to be
+ * killed is not already running at high (RT) priorities, speed up the
+ * recovery by boosting the dying task to the lowest FIFO priority.
+ * That helps with the recovery and avoids interfering with RT tasks.
+ */
+static void boost_dying_task_prio(struct task_struct *p,
+ struct mem_cgroup *mem)
+{
+ struct sched_param param = { .sched_priority = 1 };
+
+ if (mem)
+ return;
+
+ if (!rt_task(p))
+ sched_setscheduler_nocheck(p, SCHED_FIFO, &param);
+}
+
+/*
* The process p may have detached its own ->mm while exiting or through
* use_mm(), but one or more of its subthreads may still have a valid
* pointer. Return p, or any of its subthreads with a valid ->mm, with
@@ -421,7 +439,7 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
}
#define K(x) ((x) << (PAGE_SHIFT-10))
-static int oom_kill_task(struct task_struct *p)
+static int oom_kill_task(struct task_struct *p, struct mem_cgroup *mem)
{
p = find_lock_task_mm(p);
if (!p) {
@@ -434,9 +452,17 @@ static int oom_kill_task(struct task_struct *p)
K(get_mm_counter(p->mm, MM_FILEPAGES)));
task_unlock(p);
- p->rt.time_slice = HZ;
+
set_tsk_thread_flag(p, TIF_MEMDIE);
force_sig(SIGKILL, p);
+
+ /*
+ * We give our sacrificial lamb high priority and access to
+ * all the memory it needs. That way it should be able to
+ * exit() and clear out its resources quickly...
+ */
+ boost_dying_task_prio(p, mem);
+
return 0;
}
#undef K
@@ -460,6 +486,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
*/
if (p->flags & PF_EXITING) {
set_tsk_thread_flag(p, TIF_MEMDIE);
+ boost_dying_task_prio(p, mem);
return 0;
}
@@ -489,7 +516,7 @@ static int oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
}
} while_each_thread(p, t);
- return oom_kill_task(victim);
+ return oom_kill_task(victim, mem);
}
/*
@@ -670,6 +697,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask,
*/
if (fatal_signal_pending(current)) {
set_thread_flag(TIF_MEMDIE);
+ boost_dying_task_prio(current, NULL);
return;
}