lkml.org 
[lkml]   [2012]   [Feb]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 7/9] block: implement bio_associate_current()
Hey, Vivek.

On Fri, Feb 17, 2012 at 05:51:26PM -0500, Vivek Goyal wrote:
> Otherwise on every IO, we will end up comparing submitting tasks's
> cgroup and cic/cfqq's cgroup.

But how much is that different from checking CHANGED bit on each IO?
I mean, we can just do sth like cfqg->blkg->blkcg == bio_blkcg(bio).
It isn't expensive.

> Also this will create problems, if two threads sharing io context are
> in two different cgroups. We will frequently end up changing the
> association.

blkcg doesn't allow that anyway (it tries but is racy) and I actually
was thinking about sending a RFC patch to kill CLONE_IO.

Thanks.

--
tejun


\
 
 \ /
  Last update: 2012-02-17 23:59    [from the cache]
©2003-2011 Jasper Spaans