From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755501Ab2IFNsL (ORCPT ); Thu, 6 Sep 2012 09:48:11 -0400 Received: from merlin.infradead.org ([205.233.59.134]:42992 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753555Ab2IFNsH convert rfc822-to-8bit (ORCPT ); Thu, 6 Sep 2012 09:48:07 -0400 Message-ID: <1346939197.18408.10.camel@twins> Subject: Re: [PATCH tip/core/rcu 07/23] rcu: Provide OOM handler to motivate lazy RCU callbacks From: Peter Zijlstra To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, eric.dumazet@gmail.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, patches@linaro.org, "Paul E. McKenney" Date: Thu, 06 Sep 2012 15:46:37 +0200 In-Reply-To: <1346350718-30937-7-git-send-email-paulmck@linux.vnet.ibm.com> References: <20120830181811.GA29154@linux.vnet.ibm.com> <1346350718-30937-1-git-send-email-paulmck@linux.vnet.ibm.com> <1346350718-30937-7-git-send-email-paulmck@linux.vnet.ibm.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2012-08-30 at 11:18 -0700, Paul E. McKenney wrote: > + get_online_cpus(); > + for_each_online_cpu(cpu) > + for_each_rcu_flavor(rsp) > + smp_call_function_single(cpu, rcu_oom_notify_cpu, > + rsp, 1); > + put_online_cpus(); I guess blasting IPIs around is better than OOM but still.. do you really need to wait for each cpu individually, or would a construct using on_each_cpu() be possible, or better yet, on_each_cpu_cond()?