From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
John Stultz <john.stultz@linaro.org>,
LKML <linux-kernel@vger.kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Len Brown <len.brown@intel.com>,
Rafael Wysocki <rafael.j.wysocki@intel.com>,
Eduardo Valentin <edubezval@gmail.com>,
Paul Turner <pjt@google.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH 2/4] timer: relax tick stop in idle entry
Date: Fri, 13 Nov 2015 11:53:05 -0800 [thread overview]
Message-ID: <1447444387-23525-3-git-send-email-jacob.jun.pan@linux.intel.com> (raw)
In-Reply-To: <1447444387-23525-1-git-send-email-jacob.jun.pan@linux.intel.com>
Upon entering idle, we can turn off tick if the next timeout
is exactly one tick away. Otherwise, we could enter inner idle loop
with tick still enabled, without resched set, the tick will continue
during idle therefore less optimal in terms of energy savings.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
kernel/time/tick-sched.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 7c7ec45..bcadaab 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -606,7 +606,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
* restart it proper.
*/
delta = next_tick - basemono;
- if (delta <= (u64)TICK_NSEC) {
+ if (delta < (u64)TICK_NSEC) {
tick.tv64 = 0;
if (!ts->tick_stopped)
goto out;
--
1.9.1
next prev parent reply other threads:[~2015-11-13 19:55 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-13 19:53 [PATCH 0/4] CFS idle injection Jacob Pan
2015-11-13 19:53 ` [PATCH 1/4] ktime: add a roundup function Jacob Pan
2015-11-13 20:11 ` John Stultz
2015-11-13 22:33 ` Jacob Pan
2015-11-13 20:13 ` Thomas Gleixner
2015-11-13 22:36 ` Jacob Pan
2015-11-13 19:53 ` Jacob Pan [this message]
2015-11-13 20:22 ` [PATCH 2/4] timer: relax tick stop in idle entry Thomas Gleixner
2015-11-13 22:24 ` Jacob Pan
2015-11-16 15:06 ` Thomas Gleixner
2015-11-16 21:51 ` Jacob Pan
2015-11-16 22:01 ` Thomas Gleixner
2015-11-17 0:09 ` Jacob Pan
2015-11-19 17:43 ` Jacob Pan
2015-11-19 19:06 ` Peter Zijlstra
2015-11-19 19:21 ` Jacob Pan
2015-11-19 19:59 ` Peter Zijlstra
2015-11-19 23:41 ` Jacob Pan
2015-11-16 22:31 ` Paul E. McKenney
2015-11-16 23:05 ` Jacob Pan
2015-11-16 23:15 ` Jacob Pan
2015-11-16 23:28 ` Paul E. McKenney
2015-11-16 23:32 ` Arjan van de Ven
2015-11-16 23:40 ` Jacob Pan
2015-11-17 0:00 ` Paul E. McKenney
2015-11-16 22:32 ` Josh Triplett
2015-11-16 23:26 ` Paul E. McKenney
2015-11-17 1:41 ` Josh Triplett
2015-11-17 2:53 ` Paul E. McKenney
2015-11-17 2:57 ` Arjan van de Ven
2015-11-17 5:04 ` Paul E. McKenney
2015-11-17 10:24 ` Peter Zijlstra
2015-11-17 12:57 ` Jacob Pan
2015-11-17 13:49 ` Paul E. McKenney
2015-11-13 19:53 ` [PATCH 3/4] sched: introduce synchronized idle injection Jacob Pan
2015-11-13 20:23 ` kbuild test robot
2015-11-18 8:36 ` Ingo Molnar
2015-11-18 10:35 ` Peter Zijlstra
2015-11-18 12:27 ` Morten Rasmussen
2015-11-18 12:49 ` Peter Zijlstra
2015-11-18 14:04 ` Morten Rasmussen
2015-11-18 14:52 ` Jacob Pan
2015-11-18 15:09 ` Morten Rasmussen
2015-11-18 15:11 ` Jacob Pan
2015-11-18 15:21 ` Thomas Gleixner
2015-11-18 17:03 ` Jacob Pan
2015-11-18 16:04 ` Morten Rasmussen
2015-11-27 9:17 ` Ingo Molnar
2015-11-18 14:10 ` Jacob Pan
2015-11-27 9:17 ` Ingo Molnar
2015-12-02 17:28 ` Jacob Pan
2015-11-18 14:19 ` Arjan van de Ven
2015-11-18 15:44 ` Morten Rasmussen
2015-11-18 15:51 ` Arjan van de Ven
2015-11-19 17:24 ` Morten Rasmussen
2015-11-19 20:09 ` Peter Zijlstra
2015-11-20 9:45 ` Thomas Gleixner
2015-11-20 10:20 ` Peter Zijlstra
2015-11-20 10:58 ` Thomas Gleixner
2015-11-20 12:54 ` Peter Zijlstra
2015-11-20 18:53 ` Thomas Gleixner
2016-01-11 21:50 ` Jacob Pan
2016-01-19 12:06 ` Ingo Molnar
2016-01-19 18:00 ` Jacob Pan
2015-11-24 11:38 ` Jacob Pan
2015-11-23 17:59 ` Jacob Pan
2015-11-23 17:56 ` Javi Merino
2015-11-23 18:07 ` Peter Zijlstra
2015-11-24 9:12 ` Javi Merino
2015-11-24 10:09 ` Peter Zijlstra
2015-11-24 11:10 ` Jacob Pan
2015-11-24 12:00 ` Javi Merino
2015-11-24 18:22 ` Jacob Pan
2015-11-25 9:41 ` Javi Merino
2015-11-13 19:53 ` [PATCH 4/4] sched: add trace event for " Jacob Pan
2015-11-13 20:10 ` kbuild test robot
2015-11-19 14:39 ` Javi Merino
2015-11-19 15:35 ` Jacob Pan
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