[dm-devel] Re: [PATCH 02/24] io-controller: Core of the elevator fair queuing

Vivek Goyal vgoyal at redhat.com
Fri Aug 21 02:00:28 UTC 2009


On Fri, Aug 21, 2009 at 09:54:02AM +0800, Gui Jianfeng wrote:
> Vivek Goyal wrote:
> ...
> > +
> > +static void put_prev_io_entity(struct io_entity *entity)
> > +{
> > +	struct io_service_tree *st = entity->st;
> > +	struct io_sched_data *sd = io_entity_sched_data(entity);
> > +
> > +	st->active_entity = NULL;
> > +	sd->active_entity = NULL;
> > +
> > +	if (unlikely(entity->ioprio_changed)) {
> > +		dequeue_io_entity(entity);
> > +		io_entity_update_prio(entity);
> 
> Hi Vivek,
> 
> we don't need to update prio here for the following enqueue_io_entity() 
> is already taking care of it.
> 

Thanks Gui. Jerome already raised this point in one of the replies. Will
take care of it in next posting.

Vivek

> Signed-off-by: Gui Jianfeng <guijianfeng at cn.fujitsu.com>
> ---
>  block/elevator-fq.c |    1 -
>  1 files changed, 0 insertions(+), 1 deletions(-)
> 
> diff --git a/block/elevator-fq.c b/block/elevator-fq.c
> index 201543e..b720139 100644
> --- a/block/elevator-fq.c
> +++ b/block/elevator-fq.c
> @@ -607,7 +607,6 @@ static void put_prev_io_entity(struct io_entity *entity)
>  
>  	if (unlikely(entity->ioprio_changed)) {
>  		dequeue_io_entity(entity);
> -		io_entity_update_prio(entity);
>  		enqueue_io_entity(entity);
>  	} else
>  		__enqueue_io_entity(st, entity);
> -- 
> 1.5.4.rc3
> 




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