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Diffstat (limited to 'mm/oom_kill.c')
-rw-r--r--mm/oom_kill.c51
1 files changed, 29 insertions, 22 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 1e4a600a6163..054ff47c4478 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -47,19 +47,21 @@ static DEFINE_SPINLOCK(zone_scan_lock);
#ifdef CONFIG_NUMA
/**
* has_intersects_mems_allowed() - check task eligiblity for kill
- * @tsk: task struct of which task to consider
+ * @start: task struct of which task to consider
* @mask: nodemask passed to page allocator for mempolicy ooms
*
* Task eligibility is determined by whether or not a candidate task, @tsk,
* shares the same mempolicy nodes as current if it is bound by such a policy
* and whether or not it has the same set of allowed cpuset nodes.
*/
-static bool has_intersects_mems_allowed(struct task_struct *tsk,
+static bool has_intersects_mems_allowed(struct task_struct *start,
const nodemask_t *mask)
{
- struct task_struct *start = tsk;
+ struct task_struct *tsk;
+ bool ret = false;
- do {
+ rcu_read_lock();
+ for_each_thread(start, tsk) {
if (mask) {
/*
* If this is a mempolicy constrained oom, tsk's
@@ -67,19 +69,20 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk,
* mempolicy intersects current, otherwise it may be
* needlessly killed.
*/
- if (mempolicy_nodemask_intersects(tsk, mask))
- return true;
+ ret = mempolicy_nodemask_intersects(tsk, mask);
} else {
/*
* This is not a mempolicy constrained oom, so only
* check the mems of tsk's cpuset.
*/
- if (cpuset_mems_allowed_intersects(current, tsk))
- return true;
+ ret = cpuset_mems_allowed_intersects(current, tsk);
}
- } while_each_thread(start, tsk);
+ if (ret)
+ break;
+ }
+ rcu_read_unlock();
- return false;
+ return ret;
}
#else
static bool has_intersects_mems_allowed(struct task_struct *tsk,
@@ -97,16 +100,21 @@ static bool has_intersects_mems_allowed(struct task_struct *tsk,
*/
struct task_struct *find_lock_task_mm(struct task_struct *p)
{
- struct task_struct *t = p;
+ struct task_struct *t;
- do {
+ rcu_read_lock();
+
+ for_each_thread(p, t) {
task_lock(t);
if (likely(t->mm))
- return t;
+ goto found;
task_unlock(t);
- } while_each_thread(p, t);
+ }
+ t = NULL;
+found:
+ rcu_read_unlock();
- return NULL;
+ return t;
}
/* return true if the task is not adequate as candidate victim task. */
@@ -301,7 +309,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
unsigned long chosen_points = 0;
rcu_read_lock();
- do_each_thread(g, p) {
+ for_each_process_thread(g, p) {
unsigned int points;
switch (oom_scan_process_thread(p, totalpages, nodemask,
@@ -323,7 +331,7 @@ static struct task_struct *select_bad_process(unsigned int *ppoints,
chosen = p;
chosen_points = points;
}
- } while_each_thread(g, p);
+ }
if (chosen)
get_task_struct(chosen);
rcu_read_unlock();
@@ -406,7 +414,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
{
struct task_struct *victim = p;
struct task_struct *child;
- struct task_struct *t = p;
+ struct task_struct *t;
struct mm_struct *mm;
unsigned int victim_points = 0;
static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
@@ -437,7 +445,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
* still freeing memory.
*/
read_lock(&tasklist_lock);
- do {
+ for_each_thread(p, t) {
list_for_each_entry(child, &t->children, sibling) {
unsigned int child_points;
@@ -455,13 +463,11 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
get_task_struct(victim);
}
}
- } while_each_thread(p, t);
+ }
read_unlock(&tasklist_lock);
- rcu_read_lock();
p = find_lock_task_mm(victim);
if (!p) {
- rcu_read_unlock();
put_task_struct(victim);
return;
} else if (victim != p) {
@@ -487,6 +493,7 @@ void oom_kill_process(struct task_struct *p, gfp_t gfp_mask, int order,
* That thread will now get access to memory reserves since it has a
* pending fatal signal.
*/
+ rcu_read_lock();
for_each_process(p)
if (p->mm == mm && !same_thread_group(p, victim) &&
!(p->flags & PF_KTHREAD)) {