On Mon, Sep 8, 2014 at 4:23 PM, Rafael J. Wysocki <r...@rjwysocki.net> wrote: > > The reason why it matters for the suspend-time freezing is that we freeze > tasks > to take them out of the picture entirely until they are thawed. Therefore we > can't allow them to go back to the picture just for a while until they are > killed. Frozen tasks are not supposed to get back to the picture at all. >
Ok, then checking TIF_MEMDIE is unsafe for PM freeze, we should keep the cgroup_freezing() test to make sure freeze request is from cgroup not PM. Question got answered. :) I will put the following as a comment: /* OOM killer may decide to kill this process after it is frozen, in this case SIGKILL can never be handled, so we should check TIF_MEMDIE and if it is set, thaw and let SIGKILL kill it. But for PM freeze, it is not allowed to get out even for a while, so we have to keep it being frozen. */ Let me know if it looks good to you. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
