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由 Cong Wang 提交于
Since f660daac (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 a3201227 (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 f660daac. Fix the issue by checking for TIF_MEMDIE thread flag in freezing_slow_path and exclude the task from freezing completely. If a task was already frozen it would get woken by __thaw_task from OOM killer and get out of freezer after rechecking freezing(). Changes since v1 - put TIF_MEMDIE check into freezing_slowpath rather than in __refrigerator as per Oleg - return __thaw_task into oom_scan_process_thread because oom_kill_process will not wake task in the fridge because it is sleeping uninterruptible [mhocko@suse.cz: rewrote the changelog] Fixes: a3201227 (freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE) Cc: 3.3+ <stable@vger.kernel.org> # 3.3+ Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com> Signed-off-by: NMichal Hocko <mhocko@suse.cz> Acked-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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