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From: Frederic Weisbecker <fweisbec@gmail.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Chris Metcalf <cmetcalf@tilera.com>,
	Christoph Lameter <cl@linux.com>,
	Geoff Levand <geoff@infradead.org>,
	Gilad Ben Yossef <gilad@benyossef.com>,
	Hakan Akkan <hakanakkan@gmail.com>,
	Kevin Hilman <khilman@linaro.org>,
	Li Zhong <zhong@linux.vnet.ibm.com>,
	Oleg Nesterov <oleg@redhat.com>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 01/10] posix_timers: Fix pre-condition to stop the tick on full dynticks
Date: Mon, 22 Apr 2013 20:59:37 +0200	[thread overview]
Message-ID: <1366657186-20556-2-git-send-email-fweisbec@gmail.com> (raw)
In-Reply-To: <1366657186-20556-1-git-send-email-fweisbec@gmail.com>

The test that checks if a CPU can stop its tick from posix CPU
timers angle was mistakenly inverted.

What we want is to prevent the tick from being stopped as long
as the current CPU's task runs a posix CPU timer.

Fix this.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/posix-cpu-timers.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 84d5cb3..42670e9 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -673,12 +673,12 @@ static void posix_cpu_timer_kick_nohz(void)
 bool posix_cpu_timers_can_stop_tick(struct task_struct *tsk)
 {
 	if (!task_cputime_zero(&tsk->cputime_expires))
-		return true;
+		return false;
 
 	if (tsk->signal->cputimer.running)
-		return true;
+		return false;
 
-	return false;
+	return true;
 }
 #else
 static inline void posix_cpu_timer_kick_nohz(void) { }
-- 
1.7.5.4


  reply	other threads:[~2013-04-22 19:02 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-04-22 18:59 [GIT PULL] nohz: Adaptively stop the tick, finally Frederic Weisbecker
2013-04-22 18:59 ` Frederic Weisbecker [this message]
2013-04-22 18:59 ` [PATCH 02/10] perf: Kick full dynticks CPU if events rotation is needed Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 03/10] perf: New helper to prevent full dynticks CPUs from stopping tick Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 04/10] sched: Kick full dynticks CPU that have more than one task enqueued Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 05/10] sched: New helper to prevent from stopping the tick in full dynticks Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 06/10] nohz: Re-evaluate the tick from the scheduler IPI Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 07/10] nohz: Implement full dynticks kick Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 08/10] nohz: Prepare to stop the tick on irq exit Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 09/10] nohz: Re-evaluate the tick for the new task after a context switch Frederic Weisbecker
2013-04-22 18:59 ` [PATCH 10/10] nohz: Disable the tick when irq resume in full dynticks CPU Frederic Weisbecker
2013-04-24  7:32 ` [GIT PULL] nohz: Adaptively stop the tick, finally Ingo Molnar
2013-04-24  7:38   ` Ingo Molnar
2013-04-24 14:50     ` Frederic Weisbecker
2013-04-25  6:28       ` Ingo Molnar

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