From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754590Ab1ATUX0 (ORCPT ); Thu, 20 Jan 2011 15:23:26 -0500 Received: from hera.kernel.org ([140.211.167.34]:54781 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754335Ab1ATUXX (ORCPT ); Thu, 20 Jan 2011 15:23:23 -0500 Date: Thu, 20 Jan 2011 20:22:06 GMT From: tip-bot for Tejun Heo Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, torvalds@linux-foundation.org, penberg@kernel.org, peterz@infradead.org, tj@kernel.org, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, penberg@kernel.org, tj@kernel.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20110120110713.GC6036@htj.dyndns.org> References: <20110120110713.GC6036@htj.dyndns.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c Message-ID: Git-Commit-ID: bd924e8cbd4b73ffb7d707a774c04f7e2cae88ed X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 20 Jan 2011 20:22:06 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: bd924e8cbd4b73ffb7d707a774c04f7e2cae88ed Gitweb: http://git.kernel.org/tip/bd924e8cbd4b73ffb7d707a774c04f7e2cae88ed Author: Tejun Heo AuthorDate: Thu, 20 Jan 2011 12:07:13 +0100 Committer: Ingo Molnar CommitDate: Thu, 20 Jan 2011 13:32:34 +0100 smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c percpu may end up calling vfree() during early boot which in turn may call on_each_cpu() for TLB flushes. The function of on_each_cpu() can be done safely while IRQ is disabled during early boot but it assumed that the function is always called with local IRQ enabled which ended up enabling local IRQ prematurely during boot and triggering a couple of warnings. This patch updates on_each_cpu() and smp_call_function_many() such on_each_cpu() can be used safely while early_boot_irqs_disabled is set. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Acked-by: Pekka Enberg Cc: Linus Torvalds LKML-Reference: <20110120110713.GC6036@htj.dyndns.org> Signed-off-by: Ingo Molnar Reported-by: Ingo Molnar --- kernel/smp.c | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/smp.c b/kernel/smp.c index 4ec30e0..4b83cd6 100644 --- a/kernel/smp.c +++ b/kernel/smp.c @@ -430,7 +430,7 @@ void smp_call_function_many(const struct cpumask *mask, * can't happen. */ WARN_ON_ONCE(cpu_online(this_cpu) && irqs_disabled() - && !oops_in_progress); + && !oops_in_progress && !early_boot_irqs_disabled); /* So, what's a CPU they want? Ignoring this one. */ cpu = cpumask_first_and(mask, cpu_online_mask); @@ -533,17 +533,20 @@ void ipi_call_unlock_irq(void) #endif /* USE_GENERIC_SMP_HELPERS */ /* - * Call a function on all processors + * Call a function on all processors. May be used during early boot while + * early_boot_irqs_disabled is set. Use local_irq_save/restore() instead + * of local_irq_disable/enable(). */ int on_each_cpu(void (*func) (void *info), void *info, int wait) { + unsigned long flags; int ret = 0; preempt_disable(); ret = smp_call_function(func, info, wait); - local_irq_disable(); + local_irq_save(flags); func(info); - local_irq_enable(); + local_irq_restore(flags); preempt_enable(); return ret; }