On 04/17/2014 12:50 AM, Tejun Heo wrote: > Hello, Lai. > > On Thu, Apr 17, 2014 at 12:21:21AM +0800, Lai Jiangshan wrote: >> OK. It is better to use get_pwq(). I will also change the above comments to: >> >> The base ref and the possible ref from rerscuer(stopped) are never >> dropped on per-cpu pwqs. >> Directly free the pwqs and wq. > > Hmmm, why does that matter? The base ref is the business of > create/destroy path and as long as base ref is never put other refs > just don't matter. > >> The reason I quickly dropped V1 and wrote the V2 is that I saw this comment. >> "The base ref" is precise after I used get_pwq() in V1. >> >> Or to avoid to change to this comments. >> I can also move the following code down to the bottom of the >> rescuer_thread(). >> >> if (kthread_should_stop()) { >> __set_current_state(TASK_RUNNING); >> rescuer->task->flags &= ~PF_WQ_WORKER; >> return 0; >> } >> >> (I reply this email on browser, never mind the syntax). >> Maybe the second choice are better. > > Hmmm... yeah, regardlesss of the above, it's a bit nasty that rescuer > may exit with non-empty mayday list. >
+ * The wq->maydays list maybe still have some pwqs linked, + * but it is safe to free them all together since the rescuer + * is stopped. I just comment it without fix. It has no harm before, but it harms after I added a get_pwq(). Sorry. Lai -- 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/