From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934380Ab3BMQNS (ORCPT ); Wed, 13 Feb 2013 11:13:18 -0500 Received: from www.linutronix.de ([62.245.132.108]:59729 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934364Ab3BMQNQ (ORCPT ); Wed, 13 Feb 2013 11:13:16 -0500 From: Sebastian Andrzej Siewior To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Carsten Emde , Thomas Gleixner , Sebastian Andrzej Siewior Subject: [PATCH 07/16] softirq: Fix nohz pending issue for real Date: Wed, 13 Feb 2013 17:12:02 +0100 Message-Id: <1360771932-27150-8-git-send-email-bigeasy@linutronix.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1360771932-27150-1-git-send-email-bigeasy@linutronix.de> References: <1360771932-27150-1-git-send-email-bigeasy@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner We really need to iterate through all softirqs to find a potentially blocked runner. T1 runs softirq X (that cleared pending bit for X) Interrupt raises softirq Y T1 gets blocked on a lock and lock owner is not runnable T1 schedules out CPU goes idle and complains about pending softirq Y. Now iterating over all softirqs lets us find the runner for X and eliminate Y from the to warn about list as well. Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior --- kernel/softirq.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 385fcea..1a0145a 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -100,20 +100,15 @@ void softirq_check_pending_idle(void) { static int rate_limit; struct softirq_runner *sr = &__get_cpu_var(softirq_runners); - u32 warnpending, pending = local_softirq_pending(); + u32 warnpending = local_softirq_pending(); + int i; if (rate_limit >= 10) return; - warnpending = pending; - - while (pending) { - struct task_struct *tsk; - int i = __ffs(pending); - - pending &= ~(1 << i); + for (i = 0; i < NR_SOFTIRQS; i++) { + struct task_struct *tsk = sr->runner[i]; - tsk = sr->runner[i]; /* * The wakeup code in rtmutex.c wakes up the task * _before_ it sets pi_blocked_on to NULL under -- 1.7.10.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: [PATCH 07/16] softirq: Fix nohz pending issue for real Date: Wed, 13 Feb 2013 17:12:02 +0100 Message-ID: <1360771932-27150-8-git-send-email-bigeasy@linutronix.de> References: <1360771932-27150-1-git-send-email-bigeasy@linutronix.de> Cc: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Carsten Emde , Thomas Gleixner , Sebastian Andrzej Siewior To: Steven Rostedt Return-path: Received: from www.linutronix.de ([62.245.132.108]:59729 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934364Ab3BMQNQ (ORCPT ); Wed, 13 Feb 2013 11:13:16 -0500 In-Reply-To: <1360771932-27150-1-git-send-email-bigeasy@linutronix.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: From: Thomas Gleixner We really need to iterate through all softirqs to find a potentially blocked runner. T1 runs softirq X (that cleared pending bit for X) Interrupt raises softirq Y T1 gets blocked on a lock and lock owner is not runnable T1 schedules out CPU goes idle and complains about pending softirq Y. Now iterating over all softirqs lets us find the runner for X and eliminate Y from the to warn about list as well. Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior --- kernel/softirq.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 385fcea..1a0145a 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -100,20 +100,15 @@ void softirq_check_pending_idle(void) { static int rate_limit; struct softirq_runner *sr = &__get_cpu_var(softirq_runners); - u32 warnpending, pending = local_softirq_pending(); + u32 warnpending = local_softirq_pending(); + int i; if (rate_limit >= 10) return; - warnpending = pending; - - while (pending) { - struct task_struct *tsk; - int i = __ffs(pending);