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Message-ID: <1496342115-3974-3-git-send-email-guro@fb.com>
Date: Thu, 1 Jun 2017 19:35:10 +0100
From: Roman Gushchin <guro@...com>
To: <linux-mm@...ck.org>
CC: Roman Gushchin <guro@...com>, Tejun Heo <tj@...nel.org>,
Johannes Weiner <hannes@...xchg.org>,
Li Zefan <lizefan@...wei.com>,
Michal Hocko <mhocko@...nel.org>,
Vladimir Davydov <vdavydov.dev@...il.com>,
Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
<kernel-team@...com>, <cgroups@...r.kernel.org>,
<linux-doc@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [RFC PATCH v2 2/7] mm, oom: split oom_kill_process() and export __oom_kill_process()
The oom_kill_process() function consists of two logical parts:
a first one is responsible for considering task's children as
a potential victim and some debug output.
The second half is responsible for sending SIGKILL to all
tasks sharing mm with the given victim.
This commit splits the oom_kill_process() function
and exports __oom_kill_process (second half) to reuse it
from the memory cgroup code.
Signed-off-by: Roman Gushchin <guro@...com>
Cc: Tejun Heo <tj@...nel.org>
Cc: Johannes Weiner <hannes@...xchg.org>
Cc: Li Zefan <lizefan@...wei.com>
Cc: Michal Hocko <mhocko@...nel.org>
Cc: Vladimir Davydov <vdavydov.dev@...il.com>
Cc: Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
Cc: kernel-team@...com
Cc: cgroups@...r.kernel.org
Cc: linux-doc@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
Cc: linux-mm@...ck.org
---
include/linux/oom.h | 2 +
mm/oom_kill.c | 121 +++++++++++++++++++++++++++-------------------------
2 files changed, 66 insertions(+), 57 deletions(-)
diff --git a/include/linux/oom.h b/include/linux/oom.h
index 8a266e2..47d9495 100644
--- a/include/linux/oom.h
+++ b/include/linux/oom.h
@@ -79,6 +79,8 @@ extern void oom_killer_enable(void);
extern struct task_struct *find_lock_task_mm(struct task_struct *p);
+extern void __oom_kill_process(struct task_struct *victim);
+
/* sysctls */
extern int sysctl_oom_dump_tasks;
extern int sysctl_oom_kill_allocating_task;
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index f8b0fb1..11b60a5 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -803,67 +803,12 @@ static bool task_will_free_mem(struct task_struct *task)
return ret;
}
-static void oom_kill_process(struct oom_control *oc, const char *message)
+void __oom_kill_process(struct task_struct *victim)
{
- struct task_struct *p = oc->chosen;
- unsigned int points = oc->chosen_points;
- struct task_struct *victim = p;
- struct task_struct *child;
- struct task_struct *t;
+ struct task_struct *p;
struct mm_struct *mm;
- unsigned int victim_points = 0;
- static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
- DEFAULT_RATELIMIT_BURST);
bool can_oom_reap = true;
- /*
- * If the task is already exiting, don't alarm the sysadmin or kill
- * its children or threads, just set TIF_MEMDIE so it can die quickly
- */
- task_lock(p);
- if (task_will_free_mem(p)) {
- mark_oom_victim(p);
- wake_oom_reaper(p);
- task_unlock(p);
- put_task_struct(p);
- return;
- }
- task_unlock(p);
-
- if (__ratelimit(&oom_rs))
- dump_header(oc, p);
-
- pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n",
- message, task_pid_nr(p), p->comm, points);
-
- /*
- * If any of p's children has a different mm and is eligible for kill,
- * the one with the highest oom_badness() score is sacrificed for its
- * parent. This attempts to lose the minimal amount of work done while
- * still freeing memory.
- */
- read_lock(&tasklist_lock);
- for_each_thread(p, t) {
- list_for_each_entry(child, &t->children, sibling) {
- unsigned int child_points;
-
- if (process_shares_mm(child, p->mm))
- continue;
- /*
- * oom_badness() returns 0 if the thread is unkillable
- */
- child_points = oom_badness(child,
- oc->memcg, oc->nodemask, oc->totalpages);
- if (child_points > victim_points) {
- put_task_struct(victim);
- victim = child;
- victim_points = child_points;
- get_task_struct(victim);
- }
- }
- }
- read_unlock(&tasklist_lock);
-
p = find_lock_task_mm(victim);
if (!p) {
put_task_struct(victim);
@@ -930,6 +875,68 @@ static void oom_kill_process(struct oom_control *oc, const char *message)
mmdrop(mm);
put_task_struct(victim);
}
+
+static void oom_kill_process(struct oom_control *oc, const char *message)
+{
+ struct task_struct *p = oc->chosen;
+ unsigned int points = oc->chosen_points;
+ struct task_struct *victim = p;
+ struct task_struct *child;
+ struct task_struct *t;
+ unsigned int victim_points = 0;
+ static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+
+ /*
+ * If the task is already exiting, don't alarm the sysadmin or kill
+ * its children or threads, just set TIF_MEMDIE so it can die quickly
+ */
+ task_lock(p);
+ if (task_will_free_mem(p)) {
+ mark_oom_victim(p);
+ wake_oom_reaper(p);
+ task_unlock(p);
+ put_task_struct(p);
+ return;
+ }
+ task_unlock(p);
+
+ if (__ratelimit(&oom_rs))
+ dump_header(oc, p);
+
+ pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n",
+ message, task_pid_nr(p), p->comm, points);
+
+ /*
+ * If any of p's children has a different mm and is eligible for kill,
+ * the one with the highest oom_badness() score is sacrificed for its
+ * parent. This attempts to lose the minimal amount of work done while
+ * still freeing memory.
+ */
+ read_lock(&tasklist_lock);
+ for_each_thread(p, t) {
+ list_for_each_entry(child, &t->children, sibling) {
+ unsigned int child_points;
+
+ if (process_shares_mm(child, p->mm))
+ continue;
+ /*
+ * oom_badness() returns 0 if the thread is unkillable
+ */
+ child_points = oom_badness(child,
+ oc->memcg, oc->nodemask, oc->totalpages);
+ if (child_points > victim_points) {
+ put_task_struct(victim);
+ victim = child;
+ victim_points = child_points;
+ get_task_struct(victim);
+ }
+ }
+ }
+ read_unlock(&tasklist_lock);
+
+ __oom_kill_process(victim);
+}
#undef K
/*
--
2.7.4
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