This is a note to let you know that I've just added the patch titled
oom_kill: change oom_kill.c to use for_each_thread()
to the 3.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
oom_kill-change-oom_kill.c-to-use-for_each_thread.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1da4db0cd5c8a31d4468ec906b413e75e604b465 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Date: Tue, 21 Jan 2014 15:49:58 -0800
Subject: oom_kill: change oom_kill.c to use for_each_thread()
From: Oleg Nesterov <oleg@xxxxxxxxxx>
commit 1da4db0cd5c8a31d4468ec906b413e75e604b465 upstream.
Change oom_kill.c to use for_each_thread() rather than the racy
while_each_thread() which can loop forever if we race with exit.
Note also that most users were buggy even if while_each_thread() was
fine, the task can exit even _before_ rcu_read_lock().
Fortunately the new for_each_thread() only requires the stable
task_struct, so this change fixes both problems.
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Reviewed-by: Sergey Dyasly <dserrg@xxxxxxxxx>
Tested-by: Sergey Dyasly <dserrg@xxxxxxxxx>
Reviewed-by: Sameer Nanda <snanda@xxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Mandeep Singh Baines <msb@xxxxxxxxxxxx>
Cc: "Ma, Xindong" <xindong.ma@xxxxxxxxx>
Reviewed-by: Michal Hocko <mhocko@xxxxxxx>
Cc: "Tu, Xiaobing" <xiaobing.tu@xxxxxxxxx>
Acked-by: David Rientjes <rientjes@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/oom_kill.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -59,7 +59,7 @@ static bool has_intersects_mems_allowed(
{
struct task_struct *start = tsk;
- do {
+ for_each_thread(start, tsk) {
if (mask) {
/*
* If this is a mempolicy constrained oom, tsk's
@@ -77,7 +77,7 @@ static bool has_intersects_mems_allowed(
if (cpuset_mems_allowed_intersects(current, tsk))
return true;
}
- } while_each_thread(start, tsk);
+ }
return false;
}
@@ -97,14 +97,14 @@ static bool has_intersects_mems_allowed(
*/
struct task_struct *find_lock_task_mm(struct task_struct *p)
{
- struct task_struct *t = p;
+ struct task_struct *t;
- do {
+ for_each_thread(p, t) {
task_lock(t);
if (likely(t->mm))
return t;
task_unlock(t);
- } while_each_thread(p, t);
+ }
return NULL;
}
@@ -301,7 +301,7 @@ static struct task_struct *select_bad_pr
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 +323,7 @@ static struct task_struct *select_bad_pr
chosen = p;
chosen_points = points;
}
- } while_each_thread(g, p);
+ }
if (chosen)
get_task_struct(chosen);
rcu_read_unlock();
@@ -406,7 +406,7 @@ void oom_kill_process(struct task_struct
{
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 +437,7 @@ void oom_kill_process(struct task_struct
* 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;
@@ -455,7 +455,7 @@ void oom_kill_process(struct task_struct
get_task_struct(victim);
}
}
- } while_each_thread(p, t);
+ }
read_unlock(&tasklist_lock);
rcu_read_lock();
Patches currently in stable-queue which might be from oleg@xxxxxxxxxx are
queue-3.10/introduce-for_each_thread-to-replace-the-buggy-while_each_thread.patch
queue-3.10/oom_kill-change-oom_kill.c-to-use-for_each_thread.patch
queue-3.10/kernel-fork.c-copy_process-unify-clone_thread-or-thread_group_leader-code.patch
queue-3.10/oom_kill-add-rcu_read_lock-into-find_lock_task_mm.patch
queue-3.10/vm_is_stack-use-for_each_thread-rather-then-buggy-while_each_thread.patch
queue-3.10/oom_kill-has_intersects_mems_allowed-needs-rcu_read_lock.patch
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