Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753514Ab2FEPvP (ORCPT ); Tue, 5 Jun 2012 11:51:15 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56897 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751539Ab2FEPvN (ORCPT ); Tue, 5 Jun 2012 11:51:13 -0400 Date: Tue, 5 Jun 2012 08:47:56 -0700 From: tip-bot for Yong Zhang Message-ID: Cc: linux-kernel@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, mingo@kernel.org, konrad.wilk@oracle.com, peterz@infradead.org, srivatsa.bhat@linux.vnet.ibm.com, jeremy@goop.org, tglx@linutronix.de, yong.zhang0@gmail.com Reply-To: mingo@kernel.org, hpa@zytor.com, mingo@redhat.com, linux-kernel@vger.kernel.org, konrad.wilk@oracle.com, peterz@infradead.org, srivatsa.bhat@linux.vnet.ibm.com, jeremy@goop.org, yong.zhang0@gmail.com, tglx@linutronix.de In-Reply-To: <1338275765-3217-7-git-send-email-yong.zhang0@gmail.com> References: <1338275765-3217-7-git-send-email-yong.zhang0@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:smp/hotplug] x86-smp-remove-call-to-ipi_call_lock-ipi_call_unlock Git-Commit-ID: 3b6f70fd7dd4e19fc674ec99e389bf0da5589525 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Tue, 05 Jun 2012 08:48:03 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3172 Lines: 85 Commit-ID: 3b6f70fd7dd4e19fc674ec99e389bf0da5589525 Gitweb: http://git.kernel.org/tip/3b6f70fd7dd4e19fc674ec99e389bf0da5589525 Author: Yong Zhang AuthorDate: Tue, 29 May 2012 15:16:01 +0800 Committer: Thomas Gleixner CommitDate: Tue, 5 Jun 2012 17:27:12 +0200 x86-smp-remove-call-to-ipi_call_lock-ipi_call_unlock ipi_call_lock/unlock() lock resp. unlock call_function.lock. This lock protects only the call_function data structure itself, but it's completely unrelated to cpu_online_mask. The mask to which the IPIs are sent is calculated before call_function.lock is taken in smp_call_function_many(), so the locking around set_cpu_online() is pointless and can be removed. [ tglx: Massaged changelog ] Signed-off-by: Yong Zhang Cc: ralf@linux-mips.org Cc: sshtylyov@mvista.com Cc: david.daney@cavium.com Cc: nikunj@linux.vnet.ibm.com Cc: paulmck@linux.vnet.ibm.com Cc: axboe@kernel.dk Cc: peterz@infradead.org Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: Ingo Molnar Cc: "H. Peter Anvin" Link: http://lkml.kernel.org/r/1338275765-3217-7-git-send-email-yong.zhang0@gmail.com Acked-by: Srivatsa S. Bhat Acked-by: Peter Zijlstra Signed-off-by: Thomas Gleixner --- arch/x86/kernel/smpboot.c | 9 --------- arch/x86/xen/smp.c | 2 -- 2 files changed, 0 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index f56f96d..b2fd28f 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -255,22 +255,13 @@ notrace static void __cpuinit start_secondary(void *unused) check_tsc_sync_target(); /* - * We need to hold call_lock, so there is no inconsistency - * between the time smp_call_function() determines number of - * IPI recipients, and the time when the determination is made - * for which cpus receive the IPI. Holding this - * lock helps us to not include this cpu in a currently in progress - * smp_call_function(). - * * We need to hold vector_lock so there the set of online cpus * does not change while we are assigning vectors to cpus. Holding * this lock ensures we don't half assign or remove an irq from a cpu. */ - ipi_call_lock(); lock_vector_lock(); set_cpu_online(smp_processor_id(), true); unlock_vector_lock(); - ipi_call_unlock(); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; x86_platform.nmi_init(); diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index afb250d..f58dca7 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -80,9 +80,7 @@ static void __cpuinit cpu_bringup(void) notify_cpu_starting(cpu); - ipi_call_lock(); set_cpu_online(cpu, true); - ipi_call_unlock(); this_cpu_write(cpu_state, CPU_ONLINE); -- 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/