From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755206AbaI3V67 (ORCPT ); Tue, 30 Sep 2014 17:58:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9942 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755183AbaI3V64 (ORCPT ); Tue, 30 Sep 2014 17:58:56 -0400 Message-ID: <542B277D.7050103@redhat.com> Date: Tue, 30 Sep 2014 17:58:21 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Nicolas Pitre , Peter Zijlstra , Ingo Molnar CC: Daniel Lezcano , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: Re: [PATCH v2 2/2] sched/fair: leverage the idle state info when choosing the "idlest" cpu References: <1409844730-12273-1-git-send-email-nicolas.pitre@linaro.org> <1409844730-12273-3-git-send-email-nicolas.pitre@linaro.org> In-Reply-To: <1409844730-12273-3-git-send-email-nicolas.pitre@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 09/04/2014 11:32 AM, Nicolas Pitre wrote: > The code in find_idlest_cpu() looks for the CPU with the smallest > load. However, if multiple CPUs are idle, the first idle CPU is > selected irrespective of the depth of its idle state. > > Among the idle CPUs we should pick the one with with the shallowest > idle state, or the latest to have gone idle if all idle CPUs are in > the same state. The later applies even when cpuidle is configured > out. > > This patch doesn't cover the following issues: The main thing it does not cover is already running tasks that get woken up again, since select_idle_sibling() covers everything except for newly forked and newly executed tasks. I am looking at adding similar logic to select_idle_sibling() - -- All rights reversed -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJUKyd9AAoJEM553pKExN6DXZgH/1R26XfYv2FzYV9IGbty3vVx 1kMPozdb7jRAUR8+WkUgs7ntkbqau2hC/nTjDsSsiLQwXdjaDdqvnbt8Y6srI1es /Z+IRaIPGx24D7D6nB5sLgsAq6DsANUdtFK3TsED8+07LbiY71o64YQ3X1IEVyRO FKBcDw9+DBPGVySKIdMm0h2txdnQ3Jy2lM3nKV8tBFheRuOhU4Rv/fumEYAUYvDV J9y91RhKOeEJYmaYL6oQYtZgBqhDoJmh/0DjOrK6H71oZYiNWeIUxtieNXaNQp7B Rd8khOVFLsf/qZK6qjmgnfO9Mm5ij/PvrALOBZt8O9KAD3/v3kXfWIm9tO1NDZU= =kTdn -----END PGP SIGNATURE-----