In multi-threading environment, if the current task(A) have got
the mm->mmap_sem semaphore, and the thread(B) in the same process
is selected to be oom killed, because they shares the same semaphore,
thread B can not really be killed. So __alloc_pages_slowpath turns
to be a infinite loop. Here set all the threads in the group to
TIF_MEMDIE, it gets a chance to break and exit.
Signed-off-by: Anfei Zhou <anfei.zhou@xxxxxxxxx>
---
mm/oom_kill.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 9b223af..aab9892 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -381,6 +381,8 @@ static void dump_header(struct task_struct *p, gfp_t gfp_mask, int order,
*/
static void __oom_kill_task(struct task_struct *p, int verbose)
{
+ struct task_struct *t;
+
if (is_global_init(p)) {
WARN_ON(1);
printk(KERN_WARNING "tried to kill init!\n");
@@ -412,6 +414,8 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
*/
p->rt.time_slice = HZ;
set_tsk_thread_flag(p, TIF_MEMDIE);
+ for (t = next_thread(p); t != p; t = next_thread(t))
+ set_tsk_thread_flag(t, TIF_MEMDIE);
force_sig(SIGKILL, p);
}
--
1.6.4.rc1
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