On Tue, 29 Jul 2014, Tejun Heo wrote: > Hmmm, well, then it's something else. Either a bug in workqueue or in > the caller. Given the track record, the latter is more likely. > e.g. it looks kinda suspicious that the work func is cleared after > cancel_delayed_work_sync() is called. What happens if somebody tries > to schedule it inbetween? Here is yet another patch to also address this idea: Subject: vmstat: Clear the work.func before cancelling delayed work Looks strange to me but Tejun thinks this could do some good. If this really is the right thing to do then cancel_delayed_work should zap the work func itselt I think. Signed-off-by: Christoph Lameter <cl@xxxxxxxxx> Index: linux/mm/vmstat.c =================================================================== --- linux.orig/mm/vmstat.c 2014-07-29 10:22:45.073884943 -0500 +++ linux/mm/vmstat.c 2014-07-29 10:34:45.083369228 -0500 @@ -1277,8 +1277,8 @@ static int vmstat_cpuup_callback(struct break; case CPU_DOWN_PREPARE: case CPU_DOWN_PREPARE_FROZEN: - cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); per_cpu(vmstat_work, cpu).work.func = NULL; + cancel_delayed_work_sync(&per_cpu(vmstat_work, cpu)); break; case CPU_DOWN_FAILED: case CPU_DOWN_FAILED_FROZEN: -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>