The patch titled Subject: freezer: check OOM kill while being frozen has been removed from the -mm tree. Its filename was freezer-check-oom-kill-while-being-frozen.patch This patch was dropped because an updated version will be merged ------------------------------------------------------ From: Cong Wang <xiyou.wangcong@xxxxxxxxx> Subject: freezer: check OOM kill while being frozen Since f660daac474c6f ("oom: thaw threads if oom killed thread is frozen before deferring") OOM killer relies on being able to thaw a frozen task to handle OOM situation but a3201227f803 (freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE) has reorganized the code and stopped clearing freeze flag in __thaw_task. This means that the target task only wakes up and goes into the fridge again because the freezing condition hasn't changed for it. This reintroduces the bug fixed by f660daac474c6f. Fix the issue by checking for TIF_MEMDIE thread flag and get away from the fridge if it is set. oom_scan_process_thread doesn't have to check for the frozen task anymore because do_send_sig_info will wake up the thread and TIF_MEMDIE is already set by that time. Fixes: a3201227f803 (freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE) [mhocko@xxxxxxx: rewrote the changelog] Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx> Signed-off-by: Michal Hocko <mhocko@xxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [3.3+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/freezer.c | 20 +++++++++++++++++--- mm/oom_kill.c | 2 -- 2 files changed, 17 insertions(+), 5 deletions(-) diff -puN kernel/freezer.c~freezer-check-oom-kill-while-being-frozen kernel/freezer.c --- a/kernel/freezer.c~freezer-check-oom-kill-while-being-frozen +++ a/kernel/freezer.c @@ -45,13 +45,28 @@ bool freezing_slow_path(struct task_stru if (pm_nosig_freezing || cgroup_freezing(p)) return true; - if (pm_freezing && !(p->flags & PF_KTHREAD)) + if (!(p->flags & PF_KTHREAD)) return true; return false; } EXPORT_SYMBOL(freezing_slow_path); +static bool should_thaw_current(bool check_kthr_stop) +{ + if (!freezing(current)) + return true; + + if (check_kthr_stop && kthread_should_stop()) + return true; + + /* It might not be safe to check TIF_MEMDIE for pm freeze. */ + if (cgroup_freezing(current) && test_thread_flag(TIF_MEMDIE)) + return true; + + return false; +} + /* Refrigerator is place where frozen processes are stored :-). */ bool __refrigerator(bool check_kthr_stop) { @@ -67,8 +82,7 @@ bool __refrigerator(bool check_kthr_stop spin_lock_irq(&freezer_lock); current->flags |= PF_FROZEN; - if (!freezing(current) || - (check_kthr_stop && kthread_should_stop())) + if (should_thaw_current(check_kthr_stop)) current->flags &= ~PF_FROZEN; spin_unlock_irq(&freezer_lock); diff -puN mm/oom_kill.c~freezer-check-oom-kill-while-being-frozen mm/oom_kill.c --- a/mm/oom_kill.c~freezer-check-oom-kill-while-being-frozen +++ a/mm/oom_kill.c @@ -266,8 +266,6 @@ enum oom_scan_t oom_scan_process_thread( * Don't allow any other task to have access to the reserves. */ if (test_tsk_thread_flag(task, TIF_MEMDIE)) { - if (unlikely(frozen(task))) - __thaw_task(task); if (!force_kill) return OOM_SCAN_ABORT; } _ Patches currently in -mm which might be from xiyou.wangcong@xxxxxxxxx are freezer-remove-obsolete-comments-in-__thaw_task.patch oom-pm-oom-killed-task-cannot-escape-pm-suspend.patch oom-pm-oom-killed-task-cannot-escape-pm-suspend-v2.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