On Fri, 6 Nov 2015, Tetsuo Handa wrote: > So, if you refer to the blocking of the execution of vmstat updates, > description for patch 3/3 sould be updated to something like below?
Ok that is much better. > ---------- > Since __GFP_WAIT memory allocations do not call schedule() > when there is nothing to reclaim, and workqueue does not kick > remaining workqueue items unless in-flight workqueue item calls > schedule(), __GFP_WAIT memory allocation requests by workqueue > items can block vmstat_update work item forever. > > Since zone_reclaimable() decision depends on vmstat counters > to be up to dated, a silent lockup occurs because a workqueue > item doing a __GFP_WAIT memory allocation request continues > using outdated vmstat counters. > > In order to fix this problem, we need to allocate a dedicated > workqueue for vmstat. Note that this patch itself does not fix > lockup problem. Tejun will develop a patch which detects lockup > situation and kick remaining workqueue items. > ---------- > -- 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/
