lkml.org 
[lkml]   [2011]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC][PATCH 6/7] sched: Balance RT tasks when forked as well
From
Date
On Tue, 2011-07-26 at 14:36 +0200, Peter Zijlstra wrote:
> On Tue, 2011-07-26 at 08:35 -0400, Steven Rostedt wrote:
> > On Tue, 2011-07-26 at 14:25 +0200, Peter Zijlstra wrote:
> > > On Thu, 2011-06-16 at 21:55 -0400, Steven Rostedt wrote:
> > > > + /* For anything but wake ups, just return the task_cpu */
> > > > + if (sd_flag != SD_BALANCE_WAKE || sd_flag != SD_BALANCE_FORK)
> > >
> > > So we call select_task_rq() with SD_BALANCE_{WAKE,EXEC,FORK},
> > >
> > > (WAKE != WAKE -> 0 || WAKE != FORK -> 1) -> 1
> > > (EXEC != WAKE -> 1 ) -> 1
> > > (FORK != WAKE -> 1 ) -> 1
> > >
> > > IOW, you never end up doing anything now.. surely you didn't mean that?!
> >
> > Bah!
> >
> > s/||/&&/
>
> So you only want to rebalance on EXEC? The comment says you want to
> balance on wakeups. Please as to unconfuse!?

The patch is (with fixup):

+ /* For anything but wake ups, just return the task_cpu */
+ if (sd_flag != SD_BALANCE_WAKE && sd_flag != SD_BALANCE_FORK)
+ goto out;

In other words, if it isn't a WAKE or FORK (FORK being new task wakeup)
then exit the routine.

EXEC should not rebalance.

-- Steve




\
 
 \ /
  Last update: 2011-07-26 14:53    [W:0.070 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site