From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752970AbbDQKdi (ORCPT ); Fri, 17 Apr 2015 06:33:38 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:47552 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751130AbbDQKdh (ORCPT ); Fri, 17 Apr 2015 06:33:37 -0400 Message-ID: <5530E176.6030207@linux.vnet.ibm.com> Date: Fri, 17 Apr 2015 16:03:26 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Thomas Gleixner , LKML CC: Peter Zijlstra , Ingo Molnar , Viresh Kumar , Marcelo Tosatti , Frederic Weisbecker Subject: Re: [patch 34/39] tick: broadcast-hrtimer: Remove overly clever return value abuse References: <20150414203303.702062272@linutronix.de> <20150414203503.404751457@linutronix.de> In-Reply-To: <20150414203503.404751457@linutronix.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15041710-0021-0000-0000-000009E5B939 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/15/2015 02:39 AM, Thomas Gleixner wrote: > The assignment of bc_moved in the conditional construct relies on the > fact that in the case of hrtimer_start() invocation the return value > is always 0. It took me a while to understand it. > > We want to get rid of the hrtimer_start() return value. Open code the > logic which makes it readable as well. > > Signed-off-by: Thomas Gleixner > Cc: Preeti U Murthy > --- > kernel/time/tick-broadcast-hrtimer.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > Index: tip/kernel/time/tick-broadcast-hrtimer.c > =================================================================== > --- tip.orig/kernel/time/tick-broadcast-hrtimer.c > +++ tip/kernel/time/tick-broadcast-hrtimer.c > @@ -66,9 +66,11 @@ static int bc_set_next(ktime_t expires, > * hrtimer_{start/cancel} functions call into tracing, > * calls to these functions must be bound within RCU_NONIDLE. > */ > - RCU_NONIDLE(bc_moved = (hrtimer_try_to_cancel(&bctimer) >= 0) ? > - !hrtimer_start(&bctimer, expires, HRTIMER_MODE_ABS_PINNED) : > - 0); > + RCU_NONIDLE({ > + bc_moved = hrtimer_try_to_cancel(&bctimer) >= 0; > + if (bc_moved) > + hrtimer_start(&bctimer, expires, > + HRTIMER_MODE_ABS_PINNED);}); > if (bc_moved) { > /* Bind the "device" to the cpu */ > bc->bound_on = smp_processor_id(); Reviewed-by: Preeti U Murthy