Re: vmstat: On demand vmstat workers V8

From: Christoph Lameter
Date: Tue Jul 29 2014 - 11:26:29 EST


On Tue, 29 Jul 2014, Tejun Heo wrote:

> > mm/vmstat.c already has cpu down hooks. See vmstat_cpuup_callback().
>
> 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

Ok we can clear it before then.

Just looked at the current upstream code. It also does a __this_cpu_read()
in refresh_cpu_stats() without triggering the preemption check. What
changed in -next that made the test trigger now?

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/