From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752737Ab2KRBGV (ORCPT ); Sat, 17 Nov 2012 20:06:21 -0500 Received: from mail-we0-f174.google.com ([74.125.82.174]:51386 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752635Ab2KRBFL (ORCPT ); Sat, 17 Nov 2012 20:05:11 -0500 From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Steven Rostedt , Peter Zijlstra , Thomas Gleixner , Andrew Morton , Paul Gortmaker , Frederic Weisbecker Subject: [PATCH 7/9] irq_work: Warn if there's still work on cpu_down Date: Sun, 18 Nov 2012 02:04:50 +0100 Message-Id: <1353200692-6039-8-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1353200692-6039-1-git-send-email-fweisbec@gmail.com> References: <1353200692-6039-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt If we are in nohz and there's still irq_work to be done when the idle task is about to go offline, give a nasty warning. Everything should have been flushed from the CPU_DYING notifier already. Further attempts to enqueue an irq_work are buggy because irqs are disabled by __cpu_disable(). The best we can do is to report the issue to the user. Signed-off-by: Steven Rostedt Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Andrew Morton Cc: Paul Gortmaker Signed-off-by: Frederic Weisbecker --- kernel/irq_work.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 4ed1749..480f747 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -109,6 +109,9 @@ bool irq_work_needs_cpu(void) if (llist_empty(this_list)) return false; + /* All work should have been flushed before going offline */ + WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); + return true; } -- 1.7.5.4