On 01/08, Andrew Morton wrote: > > That's not correct. freeze_processes() will freeze *all* processes. All > of them are forced to enter refrigerator(). With the mysterious exception > of some I/O-related kernel threads, which might need some thought. Yes, and we can remove a dead CPU safely, this part is ok. > > and > > http://marc.theaimsgroup.com/?l=linux-kernel&m=116817460726058. > > Am not sure how that's related. but at some point we should thaw processes, including cwq->thread which should die. So we are doing things like take_over_work() and this is the source of races, because the dead CPU is not on cpu_online_map. flush_workqueue() doesn't use any locks now. If we use freezer to implement cpu-hotplug nothing will change, we still have races. It looks so obvious to me, so I'm starting to suspect I missed something very simple :( Oleg. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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