lkml.org 
[lkml]   [2007]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] cfq: fix IOPRIO_CLASS_IDLE delays
On Wed, Nov 07 2007, Oleg Nesterov wrote:
> On 11/06, Jens Axboe wrote:
> >
> > On Tue, Nov 06 2007, Oleg Nesterov wrote:
> > >
> > > (I guess this patch is not complete, overflow is still possible)
> >
> > Hmm, where would it overflow?
>
> What if the queue was idle long enough (no !CLASS_IDLE requests) so that
> jiffies wraps into the past wrt ->last_end_request?
>
> IOW, perhaps something like the patch below makes some sense. Of course,
> this is only a theoretical problem, I'm not sure we really need a fix.

OK I see what you mean, probably pretty much a theoretical problem only.
But that doesn't mean it should be fixed, I've applied your patch. It
also collects the two paths enabling the idle class timer, so I consider
it a cleanup as well as it improves readability.

--
Jens Axboe

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

\
 
 \ /
  Last update: 2007-11-07 13:55    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site