Messages in this thread | | | Date | Thu, 2 Oct 2008 06:36:06 -0700 | From | Arjan van de Ven <> | Subject | Re: [PATCH] Give kjournald a IOPRIO_CLASS_RT io priority |
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On Thu, 2 Oct 2008 15:27:47 +0200 Jens Axboe <jens.axboe@oracle.com> wrote:
> On Thu, Oct 02 2008, Arjan van de Ven wrote: > > On Thu, 2 Oct 2008 11:45:37 +0200 > > Jens Axboe <jens.axboe@oracle.com> wrote: > > > > > > > > That's a good idea, just bump the priority a little bit. Arjan, > > > did you test that out? I'd suggest just trying prio level 0 and > > > still using best-effort scheduling. Probably still need the sync > > > marking, would be interesting to experiment with though. > > > > I looked at 0 but it appears the 0 is the default for everyone... > > if everyone just defaulted to > 0 then yes I would have picked 0. > > That's not correct, class BE and value 4 is the default (and the code > defaults to that, if you haven't set a value yourself): > > #define IOPRIO_NORM (4) > static inline int task_ioprio(struct io_context *ioc) > { > if (ioprio_valid(ioc->ioprio)) > return IOPRIO_PRIO_DATA(ioc->ioprio); > > return IOPRIO_NORM; > } > > static inline int task_ioprio_class(struct io_context *ioc) > { > if (ioprio_valid(ioc->ioprio)) > return IOPRIO_PRIO_CLASS(ioc->ioprio); > > return IOPRIO_CLASS_BE; > } > > So if you use IOPRIO_CLASS_BE and 0 for the ioprio, you will have the > highest priority of the default scheduling class.
ok
I checked not by looking at the code, but running ionice -p <pid> on a bunch of things and they came back as 0
>
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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