From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754577Ab1BBQLN (ORCPT ); Wed, 2 Feb 2011 11:11:13 -0500 Received: from www.tglx.de ([62.245.132.106]:41387 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754360Ab1BBQLM (ORCPT ); Wed, 2 Feb 2011 11:11:12 -0500 Date: Wed, 2 Feb 2011 17:10:48 +0100 (CET) From: Thomas Gleixner To: LKML cc: Peter Zijlstra , Ingo Molnar , Benjamin Herrenschmidt , Heiko Carstens , David Miller , Paul Mundt Subject: [PATCH] softirq: Avoid stack switch from ksoftirqd Message-ID: User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ksoftirqd() calls do_softirq() which switches stacks on several architectures. That makes no sense at all. ksoftirqd's stack is sufficient. Call __do_softirq() directly. Signed-off-by: Thomas Gleixner --- kernel/softirq.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) Index: linux-2.6-tip/kernel/softirq.c =================================================================== --- linux-2.6-tip.orig/kernel/softirq.c +++ linux-2.6-tip/kernel/softirq.c @@ -738,7 +738,10 @@ static int run_ksoftirqd(void * __bind_c don't process */ if (cpu_is_offline((long)__bind_cpu)) goto wait_to_die; - do_softirq(); + local_irq_disable(); + if (local_softirq_pending()) + __do_softirq(); + local_irq_enable(); preempt_enable_no_resched(); cond_resched(); preempt_disable();