Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756613AbdGLMUD (ORCPT ); Wed, 12 Jul 2017 08:20:03 -0400 Received: from merlin.infradead.org ([205.233.59.134]:32998 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755296AbdGLMUC (ORCPT ); Wed, 12 Jul 2017 08:20:02 -0400 Date: Wed, 12 Jul 2017 14:19:50 +0200 From: Peter Zijlstra To: Frederic Weisbecker Cc: "Paul E. McKenney" , Aubrey Li , tglx@linutronix.de, len.brown@intel.com, rjw@rjwysocki.net, ak@linux.intel.com, tim.c.chen@linux.intel.com, arjan@linux.intel.com, yang.zhang.wz@gmail.com, x86@kernel.org, linux-kernel@vger.kernel.org, Aubrey Li Subject: Re: [RFC PATCH v1 04/11] sched/idle: make the fast idle path for short idle periods Message-ID: <20170712121950.zfcoyjnduxxgat2m@hirez.programming.kicks-ass.net> References: <1499650721-5928-1-git-send-email-aubrey.li@intel.com> <1499650721-5928-5-git-send-email-aubrey.li@intel.com> <20170711125847.GA13265@linux.vnet.ibm.com> <20170711163353.GB18805@lerouge> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170711163353.GB18805@lerouge> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 313 Lines: 8 On Tue, Jul 11, 2017 at 06:33:55PM +0200, Frederic Weisbecker wrote: > if (!tick_nohz_full_cpu(smp_processor_id()) && likely(predicted_idle_us < short_idle_threshold)) > cpuidle_fast(); > > Ugly but safer! I'd not overly worry about this, cpuidle_fast() isn't anything that's likely to ever happen.