Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752674Ab2E2IjA (ORCPT ); Tue, 29 May 2012 04:39:00 -0400 Received: from shards.monkeyblade.net ([198.137.202.13]:54704 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751253Ab2E2Ii5 (ORCPT ); Tue, 29 May 2012 04:38:57 -0400 Date: Tue, 29 May 2012 04:36:30 -0400 (EDT) Message-Id: <20120529.043630.590431449662750806.davem@davemloft.net> To: yong.zhang0@gmail.com Cc: srivatsa.bhat@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, ralf@linux-mips.org, sshtylyov@mvista.com, david.daney@cavium.com, nikunj@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com, axboe@kernel.dk, mingo@kernel.org, tglx@linutronix.de, peterz@infradead.org, akpm@linux-foundation.org, sparclinux@vger.kernel.org Subject: Re: [UPDATED] [RFC PATCH 08/10] SPARC: smp: remove call to ipi_call_lock_irq()/ipi_call_unlock_irq() From: David Miller In-Reply-To: <20120529082732.GA4250@zhy> References: <1338275765-3217-9-git-send-email-yong.zhang0@gmail.com> <4FC48272.9040904@linux.vnet.ibm.com> <20120529082732.GA4250@zhy> X-Mailer: Mew version 6.5 on Emacs 24.0.95 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (shards.monkeyblade.net [198.137.202.13]); Tue, 29 May 2012 01:36:33 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1256 Lines: 29 From: Yong Zhang Date: Tue, 29 May 2012 16:27:33 +0800 > From: Yong Zhang > Date: Tue, 29 May 2012 12:56:08 +0800 > Subject: [UPDATED] [RFC PATCH 8/10] SPARC: smp: remove call to > ipi_call_lock_irq()/ipi_call_unlock_irq() > > 1) call_function.lock used in smp_call_function_many() is just to protect > call_function.queue and &data->refs, cpu_online_mask is outside of the > lock. And it's not necessary to protect cpu_online_mask, > because data->cpumask is pre-calculate and even if a cpu is brougt up > when calling arch_send_call_function_ipi_mask(), it's harmless because > validation test in generic_smp_call_function_interrupt() will take care > of it. > > 2) For cpu down issue, stop_machine() will guarantee that no concurrent > smp_call_fuction() is processing. > > And also delay irq enable to after set_cpu_online(). > > Signed-off-by: Yong Zhang Acked-by: David S. Miller -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/