Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752125Ab1BBIy5 (ORCPT ); Wed, 2 Feb 2011 03:54:57 -0500 Received: from e23smtp01.au.ibm.com ([202.81.31.143]:45301 "EHLO e23smtp01.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751009Ab1BBIyz (ORCPT ); Wed, 2 Feb 2011 03:54:55 -0500 Message-ID: <4D491BE2.7010802@linux.vnet.ibm.com> Date: Wed, 02 Feb 2011 14:24:58 +0530 From: Ciju Rajan K User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Satoru Takeuchi CC: Ciju Rajan K , linux kernel mailing list , Peter Zijlstra , Bharata B Rao , Ingo Molnar , Srivatsa Vaddagiri Subject: Re: [PATCH 1/2 v2.0]sched: Removing unused fields from /proc/schedstat References: <4D3F3595.4020607@linux.vnet.ibm.com> <4D3F3676.1030601@linux.vnet.ibm.com> <4D3FBAD5.1070307@jp.fujitsu.com> <4D463647.7000106@linux.vnet.ibm.com> In-Reply-To: <4D463647.7000106@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1875 Lines: 48 Hi Satoru, >> I think we can remove rq->sched_switch and rq->sched_switch >> without no problem because they are meaningless. The former >> is for old O(1) scheduler and means the number of runqueue >> switching among active/expired queue. The latter is for >> SD_WAKE_BALANCE flag and its logic is already gone. >> >> However sbe_* are for SD_BALANCE_EXEC flag and sbf_* are for >> SD_BALANCE_FORK flag. Since both logic for them are still alive, >> the absence of these accounting is regression in my perspective. >> In addition, these fields would be useful for analyzing load >> balance behavior. >> The sbe_* & sbf_* counters were added by the commit 68767a0ae428801649d510d9a65bb71feed44dd1 But it was subsequently removed by the commit 476d139c218e44e045e4bc6d4cc02b010b343939 [ciju@ciju kernel]$ git describe 68767a0ae428801649d510d9a65bb71feed44dd1 --contains v2.6.13-rc1~68^2~148 [ciju@ciju kernel]$ git describe 476d139c218e44e045e4bc6d4cc02b010b343939 --contains v2.6.13-rc1~68^2~140 So.. it was introduced and removed in 2.6.13 time frame When the counters were removed the sbe_* sbf_* variable declarations were not removed. Hence it caused a little confusion. So I believe these stats were not available and hence can't be considered as regression. 476d139c218e44e045e4bc6d4cc02b010b343939 consolidated the fork and exec balance. Thereafter it became non-trivial to provide separate stats for fork and exec events. So if people think a consolidated balance-on-event is needed, it can be looked into separately. But that shouldn't prevent this documentation cleanup patch from getting in. -Ciju -- 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/