On Thu, 08 Oct 2009 10:08:36 +0200 Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > On Thu, 2009-10-08 at 09:58 +0800, Wu Fengguang wrote: > > > > > How this runqueue->nr_iowait is handled now ? > > > > Good question. io_schedule() has an old comment for throttling IO wait: > > > > * But don't do that if it is a deliberate, throttling IO wait (this task > > * has set its backing_dev_info: the queue against which it should throttle) > > */ > > void __sched io_schedule(void) > > > > So it looks both Jens' and this patch behaves right in ignoring the > > iowait accounting for balance_dirty_pages() :) > > Well it is a change in behaviour, and I think IOWAIT makes sense when > we're blocked due to io throttle.. > > Hmm? > Above comment "don't do that if it is a deliberate, throttling IO wait" is really old but ignored. I pesonally don't like to change the meanig of iowait in /proc/stat. But I'm not sure which is better to change the definitiion (which was ignored) or fix behavior (not correct very long time)... Hmm?, too ;) Regards, -Kame -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
