Subject: + oom_kill-change-oom_killc-to-use-for_each_thread.patch added to -mm tree
To: oleg@xxxxxxxxxx,dserrg@xxxxxxxxx,ebiederm@xxxxxxxxxxxx,fweisbec@xxxxxxxxx,mhocko@xxxxxxx,msb@xxxxxxxxxxxx,rientjes@xxxxxxxxxx,snanda@xxxxxxxxxxxx,xiaobing.tu@xxxxxxxxx,xindong.ma@xxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 09 Dec 2013 15:07:33 -0800
The patch titled
Subject: oom_kill: change oom_kill.c to use for_each_thread()
has been added to the -mm tree. Its filename is
oom_kill-change-oom_killc-to-use-for_each_thread.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/oom_kill-change-oom_killc-to-use-for_each_thread.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/oom_kill-change-oom_killc-to-use-for_each_thread.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Oleg Nesterov <oleg@xxxxxxxxxx>
Subject: oom_kill: change oom_kill.c to use for_each_thread()
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>
---
mm/oom_kill.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff -puN mm/oom_kill.c~oom_kill-change-oom_killc-to-use-for_each_thread mm/oom_kill.c
--- a/mm/oom_kill.c~oom_kill-change-oom_killc-to-use-for_each_thread
+++ a/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 -mm which might be from oleg@xxxxxxxxxx are
introduce-for_each_thread-to-replace-the-buggy-while_each_thread.patch
oom_kill-change-oom_killc-to-use-for_each_thread.patch
oom_kill-has_intersects_mems_allowed-needs-rcu_read_lock.patch
oom_kill-add-rcu_read_lock-into-find_lock_task_mm.patch
autofs4-allow-autofs-to-work-outside-the-initial-pid-namespace.patch
autofs4-translate-pids-to-the-right-namespace-for-the-daemon.patch
coredump-set_dumpable-fix-the-theoretical-race-with-itself.patch
coredump-kill-mmf_dumpable-and-mmf_dump_securely.patch
coredump-make-__get_dumpable-get_dumpable-inline-kill-fs-coredumph.patch
proc-cleanup-simplify-get_task_state-task_state_array.patch
proc-fix-the-potential-use-after-free-in-first_tid.patch
proc-change-first_tid-to-use-while_each_thread-rather-than-next_thread.patch
proc-dont-abuse-group_leader-in-proc_task_readdir-paths.patch
proc-fix-f_pos-overflows-in-first_tid.patch
kernel-forkc-remove-redundant-null-check-in-dup_mm.patch
exec-check_unsafe_exec-use-while_each_thread-rather-than-next_thread.patch
exec-check_unsafe_exec-kill-the-dead-eagain-and-clear_in_exec-logic.patch
exec-move-the-final-allow_write_access-fput-into-free_bprm.patch
exec-kill-task_struct-did_exec.patch
fs-proc-arrayc-change-do_task_stat-to-use-while_each_thread.patch
kernel-sysc-k_getrusage-can-use-while_each_thread.patch
kernel-signalc-change-do_signal_stop-do_sigaction-to-use-while_each_thread.patch
linux-next.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
