From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756203Ab3LDXwi (ORCPT ); Wed, 4 Dec 2013 18:52:38 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:55508 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753400Ab3LDXwf (ORCPT ); Wed, 4 Dec 2013 18:52:35 -0500 Message-ID: <529F797A.6010107@jp.fujitsu.com> Date: Wed, 04 Dec 2013 13:50:34 -0500 From: KOSAKI Motohiro User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 MIME-Version: 1.0 To: fweisbec@gmail.com, tglx@linutronix.de, mingo@kernel.org CC: kosaki.motohiro@jp.fujitsu.com, linux-kernel@vger.kernel.org, peterz@infradead.org, oleg@redhat.com, akpm@linux-foundation.org Subject: Re: [PATCH 02/10] posix-timers: Remove dead process posix cpu timers caching References: <1385221040-24731-1-git-send-email-fweisbec@gmail.com> <1385221040-24731-3-git-send-email-fweisbec@gmail.com> In-Reply-To: <1385221040-24731-3-git-send-email-fweisbec@gmail.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > @@ -1090,13 +1063,8 @@ void posix_cpu_timer_schedule(struct k_itimer *timer) > timer->it.cpu.expires = 0; > goto out_unlock; > } else if (unlikely(p->exit_state) && thread_group_empty(p)) { > - /* > - * We've noticed that the thread is dead, but > - * not yet reaped. Take this opportunity to > - * drop our task ref. > - */ > + /* Optimizations: if the process is dying, no need to rearm */ > cpu_timer_sample_group(timer->it_clock, p, &now); Why do we still need to call cpu_timer_sample_group? You removed to below line which uses "now". > - clear_dead_task(timer, now); > goto out_unlock; > } > spin_lock(&p->sighand->siglock); >