From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759004Ab2CFKsI (ORCPT ); Tue, 6 Mar 2012 05:48:08 -0500 Received: from casper.infradead.org ([85.118.1.10]:40117 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758949Ab2CFKsH convert rfc822-to-8bit (ORCPT ); Tue, 6 Mar 2012 05:48:07 -0500 Message-ID: <1331030845.11248.272.camel@twins> Subject: Re: [RFC PATCH 5/6] implement per-cpu&per-domain state machine call_srcu() From: Peter Zijlstra To: Lai Jiangshan Cc: "Paul E. McKenney" , linux-kernel@vger.kernel.org, mingo@elte.hu, 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, patches@linaro.org Date: Tue, 06 Mar 2012 11:47:25 +0100 In-Reply-To: <1331027858-7648-5-git-send-email-laijs@cn.fujitsu.com> References: <1331023359-6987-1-git-send-email-laijs@cn.fujitsu.com> <1331027858-7648-1-git-send-email-laijs@cn.fujitsu.com> <1331027858-7648-5-git-send-email-laijs@cn.fujitsu.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 Tue, 2012-03-06 at 17:57 +0800, Lai Jiangshan wrote: > o The srcu callback is new thing, I hope it is completely preemptible, > even sleepable. It does in this implemetation, I use work_struct > to stand for every srcu callback. I didn't need the callbacks to sleep too, I just needed the read-side srcu bit. There's an argument against making the callbacks able to sleep like that in that you typically want to minimize the amount of work done in the callbacks, allowing them to sleep invites to callbacks that do _way_ too much work. I haven't made my mind up if I care yet.. :-)