From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932260AbbHNIrB (ORCPT ); Fri, 14 Aug 2015 04:47:01 -0400 Received: from casper.infradead.org ([85.118.1.10]:35148 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751952AbbHNIq5 (ORCPT ); Fri, 14 Aug 2015 04:46:57 -0400 Date: Fri, 14 Aug 2015 10:46:52 +0200 From: Peter Zijlstra To: Yuyang Du Cc: Byungchul Park , mingo@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sched: sync with the cfs_rq when changing sched class Message-ID: <20150814084652.GJ16853@twins.programming.kicks-ass.net> References: <1439445355-24137-1-git-send-email-byungchul.park@lge.com> <20150813074600.GB16853@twins.programming.kicks-ass.net> <20150813082127.GO3956@byungchulpark-X58A-UD3R> <20150813021527.GB2143@intel.com> <20150813152212.GE16853@twins.programming.kicks-ass.net> <20150813232020.GA7780@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150813232020.GA7780@intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 14, 2015 at 07:20:20AM +0800, Yuyang Du wrote: > sched: Provide sched class and priority change statistics to task > > The sched class and priority changes make substantial impact for > a task, but we really have not a quantitative understanding of how > frequent they are, which makes it diffcult to work on many cases > especially some corner cases. We privide it at task level. > > Signed-off-by: Yuyang Du Sure we can do that. I would think its fairly rare on regular kernels, whilst fairly common on -RT kernels where PI is much more active.