lkml.org 
[lkml]   [2012]   [Mar]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: sched: Avoid SMT siblings in select_idle_sibling() if possible

* Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> wrote:

> * Peter Zijlstra <peterz@infradead.org> [2012-02-20 20:07:46]:
>
> > On Mon, 2012-02-20 at 19:14 +0100, Mike Galbraith wrote:

> > > Enabling SD_BALANCE_WAKE used to be decidedly too
> > > expensive to consider. Maybe that has changed, but I doubt
> > > it.
> >
> > Right, I through I remembered somet such, you could see it
> > on wakeup heavy things like pipe-bench and that java msg
> > passing thing, right?
>
> I did some experiments with volanomark and it does turn out to
> be sensitive to SD_BALANCE_WAKE, while the other wake-heavy
> benchmark that I am dealing with (Trade) benefits from it.

Does volanomark still do yield(), thereby invoking a random
shuffle of thread scheduling and pretty much voluntarily
ejecting itself from most scheduler performance considerations?

If it uses a real locking primitive such as futexes then its
performance matters more.

Thanks,

Ingo


\
 
 \ /
  Last update: 2012-03-06 10:17    [from the cache]
©2003-2011 Jasper Spaans