Re: [PATCH 1/5] cfq-iosched: Do not idle if slice_idle=0

From: Jeff Moyer
Date: Mon Aug 16 2010 - 14:37:40 EST


Vivek Goyal <vgoyal@xxxxxxxxxx> writes:

> o do not idle either on cfq queue or service tree if slice_idle=0. User does
> not want any queue or service tree idling. Currently even if slice_idle=0,
> we were waiting for request to finish before expiring the queue and that
> can lead to lower queue depths.

Hm, I submitted a similar patch that was supposed to make .35. Oh well,

Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>

>
> Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
> ---
> block/cfq-iosched.c | 5 ++++-
> 1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
> index eb4086f..8830569 100644
> --- a/block/cfq-iosched.c
> +++ b/block/cfq-iosched.c
> @@ -1839,6 +1839,9 @@ static bool cfq_should_idle(struct cfq_data *cfqd, struct cfq_queue *cfqq)
> BUG_ON(!service_tree);
> BUG_ON(!service_tree->count);
>
> + if (!cfqd->cfq_slice_idle)
> + return false;
> +
> /* We never do for idle class queues. */
> if (prio == IDLE_WORKLOAD)
> return false;
> @@ -1879,7 +1882,7 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
> /*
> * idle is disabled, either manually or by past process history
> */
> - if (!cfqd->cfq_slice_idle || !cfq_should_idle(cfqd, cfqq))
> + if (!cfq_should_idle(cfqd, cfqq))
> return;
>
> /*
--
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/