Message-ID: <1329802998.7333.1.camel@marge.simpson.net>
Subject: Re: sched: Avoid SMT siblings in select_idle_sibling() if possible
From: Mike Galbraith <efault@gmx.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@elte.hu>, Paul Turner <pjt@google.com>,
        Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Date: Tue, 21 Feb 2012 06:43:18 +0100
In-Reply-To: <1329764866.2293.376.camel@twins>
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On Mon, 2012-02-20 at 20:07 +0100, Peter Zijlstra wrote: 
> 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 some such, you could see it on wakeup
> heavy things like pipe-bench and that java msg passing thing, right?

Yeah, it beat up switch heavy buddies pretty bad.

-Mike


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