Re: [PATCH] cfq-iosched: simplify prio-unboost code

From: Jens Axboe
Date: Thu Oct 29 2009 - 09:19:53 EST


On Mon, Oct 26 2009, Corrado Zoccolo wrote:
> Eliminate redundant checks.
>
> Signed-off-by: Corrado Zoccolo <czoccolo@xxxxxxxxx>
> ---
> block/cfq-iosched.c | 8 +++-----
> 1 files changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
> index 6e9b395..244bc8a 100644
> --- a/block/cfq-iosched.c
> +++ b/block/cfq-iosched.c
> @@ -2611,12 +2611,10 @@ static void cfq_prio_boost(struct cfq_queue *cfqq)
> cfqq->ioprio = IOPRIO_NORM;
> } else {
> /*
> - * check if we need to unboost the queue
> + * unboost the queue (if needed)
> */
> - if (cfqq->ioprio_class != cfqq->org_ioprio_class)
> - cfqq->ioprio_class = cfqq->org_ioprio_class;
> - if (cfqq->ioprio != cfqq->org_ioprio)
> - cfqq->ioprio = cfqq->org_ioprio;
> + cfqq->ioprio_class = cfqq->org_ioprio_class;
> + cfqq->ioprio = cfqq->org_ioprio;
> }

Not sure I see much gain in that, the previous code makes it explicit
that it may not be different and avoid dirtying cfqq if it isn't.

--
Jens Axboe

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