Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753316Ab2E2HQm (ORCPT ); Tue, 29 May 2012 03:16:42 -0400 Received: from mail-vb0-f46.google.com ([209.85.212.46]:50104 "EHLO mail-vb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753177Ab2E2HQk (ORCPT ); Tue, 29 May 2012 03:16:40 -0400 From: Yong Zhang To: linux-kernel@vger.kernel.org Cc: 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, srivatsa.bhat@linux.vnet.ibm.com, David Howells , Koichi Yasutake , linux-am33-list@redhat.com Subject: [RFC PATCH 02/10] mn10300: smp: remove call to ipi_call_lock()/ipi_call_unlock() Date: Tue, 29 May 2012 15:15:57 +0800 Message-Id: <1338275765-3217-3-git-send-email-yong.zhang0@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1338275765-3217-1-git-send-email-yong.zhang0@gmail.com> References: <1338275765-3217-1-git-send-email-yong.zhang0@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1467 Lines: 43 From: Yong Zhang 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. Signed-off-by: Yong Zhang Cc: David Howells Cc: Koichi Yasutake Cc: linux-am33-list@redhat.com --- arch/mn10300/kernel/smp.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/arch/mn10300/kernel/smp.c b/arch/mn10300/kernel/smp.c index 090d35d..e62c223 100644 --- a/arch/mn10300/kernel/smp.c +++ b/arch/mn10300/kernel/smp.c @@ -876,9 +876,7 @@ static void __init smp_online(void) notify_cpu_starting(cpu); - ipi_call_lock(); set_cpu_online(cpu, true); - ipi_call_unlock(); local_irq_enable(); } -- 1.7.5.4 -- 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/