Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754111Ab2BWHuu (ORCPT ); Thu, 23 Feb 2012 02:50:50 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:58130 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753316Ab2BWHut (ORCPT ); Thu, 23 Feb 2012 02:50:49 -0500 Date: Thu, 23 Feb 2012 08:50:27 +0100 From: Ingo Molnar To: Venkatesh Pallipadi Cc: Peter Zijlstra , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Suresh Siddha , Aaron Durbin , Paul Turner , Yong Zhang , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Extend mwait idle to optimize away CAL and RES interrupts to an idle CPU -v1 Message-ID: <20120223075027.GB15306@elte.hu> References: <1329957415-15239-1-git-send-email-venki@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1329957415-15239-1-git-send-email-venki@google.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=AWL,BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 0.0 AWL AWL: From: address is in the auto white-list Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1291 Lines: 38 * Venkatesh Pallipadi wrote: > * Do we need some accounting for these wakeups exported for powertop? If then tracepoints. > * We can also eliminate TS_POLLING flag in favor of this. But, that will have > a lot more touchpoints and better done as a standlone change. Should most definitely be done for this series to be acceptble - as a preparatory patch in the series, with the feature at the end of the series. > +DECLARE_PER_CPU(atomic_t *, idle_task_ti_flags); That's ugly, we should access the idle task's ti flags directly. To have efficient percpu access to the idle threads another clean-up is needed: we should turn idle_thread_array into a full-structure PER_CPU area. For that we need a small variant of fork_idle(), which does not dup the init thread - pretty trivial. fork_idle() should also make sure it does not schedule the child thread: thus we'd also be able to further simplify smpboot.c and get rid of all that extremely ugly 'struct create_idle' gymnastics in smpboot.c. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/