From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752732Ab2KRBFO (ORCPT ); Sat, 17 Nov 2012 20:05:14 -0500 Received: from mail-wi0-f172.google.com ([209.85.212.172]:42374 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752546Ab2KRBFI (ORCPT ); Sat, 17 Nov 2012 20:05:08 -0500 From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Steven Rostedt , Peter Zijlstra , Thomas Gleixner , Andrew Morton , Paul Gortmaker Subject: [PATCH 5/9] irq_work: Don't stop the tick with pending works Date: Sun, 18 Nov 2012 02:04:48 +0100 Message-Id: <1353200692-6039-6-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 Don't stop the tick if we have pending irq works on the queue, otherwise if the arch can't raise self-IPIs, we may not find an opportunity to execute the pending works for a while. Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Andrew Morton Cc: Paul Gortmaker --- include/linux/irq_work.h | 6 ++++++ kernel/irq_work.c | 11 +++++++++++ kernel/time/tick-sched.c | 3 ++- 3 files changed, 19 insertions(+), 1 deletions(-) diff --git a/include/linux/irq_work.h b/include/linux/irq_work.h index 6a9e8f5..a69704f 100644 --- a/include/linux/irq_work.h +++ b/include/linux/irq_work.h @@ -20,4 +20,10 @@ bool irq_work_queue(struct irq_work *work); void irq_work_run(void); void irq_work_sync(struct irq_work *work); +#ifdef CONFIG_IRQ_WORK +bool irq_work_needs_cpu(void); +#else +static bool irq_work_needs_cpu(void) { return false; } +#endif + #endif /* _LINUX_IRQ_WORK_H */ diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 64eddd5..b3c113a 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -99,6 +99,17 @@ bool irq_work_queue(struct irq_work *work) } EXPORT_SYMBOL_GPL(irq_work_queue); +bool irq_work_needs_cpu(void) +{ + struct llist_head *this_list; + + this_list = &__get_cpu_var(irq_work_list); + if (llist_empty(this_list)) + return false; + + return true; +} + /* * Run the irq_work entries on this cpu. Requires to be ran from hardirq * context with local IRQs disabled. diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 9e945aa..f249e8c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -20,6 +20,7 @@ #include #include #include +#include #include @@ -289,7 +290,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, } while (read_seqretry(&xtime_lock, seq)); if (rcu_needs_cpu(cpu, &rcu_delta_jiffies) || printk_needs_cpu(cpu) || - arch_needs_cpu(cpu)) { + arch_needs_cpu(cpu) || irq_work_needs_cpu()) { next_jiffies = last_jiffies + 1; delta_jiffies = 1; } else { -- 1.7.5.4