From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755807Ab0K3SMT (ORCPT ); Tue, 30 Nov 2010 13:12:19 -0500 Received: from hera.kernel.org ([140.211.167.34]:57183 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166Ab0K3SMS (ORCPT ); Tue, 30 Nov 2010 13:12:18 -0500 Message-ID: <4CF53E61.1030307@kernel.org> Date: Tue, 30 Nov 2010 19:11:45 +0100 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.12) Gecko/20101103 Fedora/1.0-0.33.b2pre.fc14 Lightning/1.0b2 Thunderbird/3.1.6 MIME-Version: 1.0 To: Tejun Heo CC: linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, hpa@zytor.com, x86@kernel.org, eric.dumazet@gmail.com, yinghai@kernel.org, brgerst@gmail.com, gorcunov@gmail.com, penberg@kernel.org Subject: [PATCH UPDATED#2 04/16] x86: Use local variable to cache smp_processor_id() in setup_local_APIC() References: <1290871325-3055-1-git-send-email-tj@kernel.org> <1290871325-3055-5-git-send-email-tj@kernel.org> In-Reply-To: <1290871325-3055-5-git-send-email-tj@kernel.org> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Tue, 30 Nov 2010 18:11:48 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a trivial clean up. * Move initialization of @cpu inside preemption disabled region as suggested by Cyrill Gorcunov. Signed-off-by: Tejun Heo Cc: Yinghai Lu Cc: Cyrill Gorcunov --- Alright, updated yet again, but I frankly don't see the point in these changes. If setup_local_APIC() is being run from a different CPU, we have a much larger problem. We're already accessing cpu local resources (tsc, lapic) outside of preemption disabled area. But, anyways, I don't think it matters one way or the other. Thanks. arch/x86/kernel/apic/apic.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) Index: work/arch/x86/kernel/apic/apic.c =================================================================== --- work.orig/arch/x86/kernel/apic/apic.c +++ work/arch/x86/kernel/apic/apic.c @@ -1202,7 +1202,7 @@ static void __cpuinit lapic_setup_esr(vo void __cpuinit setup_local_APIC(void) { unsigned int value, queued; - int i, j, acked = 0; + int cpu, i, j, acked = 0; unsigned long long tsc = 0, ntsc; long long max_loops = cpu_khz; @@ -1226,6 +1226,7 @@ void __cpuinit setup_local_APIC(void) perf_events_lapic_init(); preempt_disable(); + cpu = smp_processor_id(); /* * Double-check whether this APIC is really registered. @@ -1342,21 +1343,19 @@ void __cpuinit setup_local_APIC(void) * TODO: set up through-local-APIC from through-I/O-APIC? --macro */ value = apic_read(APIC_LVT0) & APIC_LVT_MASKED; - if (!smp_processor_id() && (pic_mode || !value)) { + if (!cpu && (pic_mode || !value)) { value = APIC_DM_EXTINT; - apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", - smp_processor_id()); + apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu); } else { value = APIC_DM_EXTINT | APIC_LVT_MASKED; - apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", - smp_processor_id()); + apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu); } apic_write(APIC_LVT0, value); /* * only the BP should see the LINT1 NMI signal, obviously. */ - if (!smp_processor_id()) + if (!cpu) value = APIC_DM_NMI; else value = APIC_DM_NMI | APIC_LVT_MASKED;