lkml.org 
[lkml]   [2012]   [Jan]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [patch v2 8/8]block: fiops sync preempts async
From
Hello Shaohua

On Mon, Jan 30, 2012 at 3:02 PM, Shaohua Li <shaohua.li@intel.com> wrote:
> Debug patch only.
>
> This implements CFQ like sync preempts async. But like CFQ, this
> will starve async.
>
> ---
>  block/fiops-iosched.c |   15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> Index: linux/block/fiops-iosched.c
> ===================================================================
> --- linux.orig/block/fiops-iosched.c    2012-01-21 10:35:04.000000000 +0800
> +++ linux/block/fiops-iosched.c 2012-01-21 10:48:52.000000000 +0800
> @@ -408,6 +408,21 @@ static struct fiops_ioc *fiops_select_io
>                return NULL;
>        }
>
> +       /* Let sync request preempt async queue */
> +       if (!rq_is_sync(rq) && service_tree->count > 1) {
> +               struct rb_node *tmp = rb_next(&ioc->rb_node);
> +               struct fiops_ioc *sync_ioc = NULL;
> +               while (tmp) {
> +                       sync_ioc = rb_entry(tmp, struct fiops_ioc, rb_node);
> +                       rq = rq_entry_fifo(sync_ioc->fifo.next);
> +                       if (rq_is_sync(rq))
> +                               break;
> +                       tmp = rb_next(&sync_ioc->rb_node);

sync_ioc = NULL; yes?
Hillf
> +               }
> +               if (sync_ioc)
> +                       ioc = sync_ioc;
> +       }
> +
>        return ioc;
>  }
>
\
 
 \ /
  Last update: 2012-01-30 12:55    [W:0.058 / U:3.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site