From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751316AbcFAUSY (ORCPT ); Wed, 1 Jun 2016 16:18:24 -0400 Received: from merlin.infradead.org ([205.233.59.134]:50054 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765AbcFAUSW (ORCPT ); Wed, 1 Jun 2016 16:18:22 -0400 Date: Wed, 1 Jun 2016 22:18:17 +0200 From: Peter Zijlstra To: Morten Rasmussen Cc: mingo@redhat.com, dietmar.eggemann@arm.com, yuyang.du@intel.com, vincent.guittot@linaro.org, mgalbraith@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH 07/16] sched: Make SD_BALANCE_WAKE a topology flag Message-ID: <20160601201817.GF28447@twins.programming.kicks-ass.net> References: <1464001138-25063-1-git-send-email-morten.rasmussen@arm.com> <1464001138-25063-8-git-send-email-morten.rasmussen@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464001138-25063-8-git-send-email-morten.rasmussen@arm.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 Mon, May 23, 2016 at 11:58:49AM +0100, Morten Rasmussen wrote: > For systems with the SD_ASYM_CPUCAPACITY flag set on higher level in the > sched_domain hierarchy we need a way to enable wake-up balancing for the > lower levels as well as we may want to balance tasks that don't fit the > capacity of the previous cpu. > > We have the option of introducing a new topology flag to express this > requirement, or let the existing SD_BALANCE_WAKE flag be set by the > architecture as a topology flag. The former means introducing yet > another flag, the latter breaks the current meaning of topology flags. > None of the options are really desirable. So why can't you couple this to ASYM_CAPACITY? If that's set anywhere, add BALANCE_WAKE as appropriate?