From: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Olivier Langlois <olivier@trillion01.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Steven Rostedt <rostedt@goodmis.org>,
David Miller <davem@davemloft.net>,
Thomas Gleixner <tglx@linutronix.de>,
Frederic Weisbecker <fweisbec@gmail.com>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
kosaki.motohiro@gmail.com
Subject: [PATCH 6/2] posix-cpu-timers: timer functions must use timer time instead of clock time
Date: Mon, 29 Apr 2013 15:20:38 -0400 [thread overview]
Message-ID: <517EC806.6040403@gmail.com> (raw)
In-Reply-To: <1367216762-3933-1-git-send-email-kosaki.motohiro@gmail.com>
For process timer, we use cpu_clock_sample_group() and cpu_timer_sample_group
correctly. However for thread timer, we always use cpu_clock_sample().
That's wrong becuase cpu_clock_sample() account uncommited delta_exec too.
This is not big matter because following workaround code in
posix_cpu_timer_get() hide the timer inversion issue. However it makes wrong
rq lock held and would be better to fix.
if (cpu_time_before(timer->it_clock, now, timer->it.cpu.expires)) {
...
} else {
/*
* The timer should have expired already, but the firing
* hasn't taken place yet. Say it's just about to expire.
*/
itp->it_value.tv_nsec = 1;
itp->it_value.tv_sec = 0;
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
---
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 9088023..472394b 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -700,7 +700,7 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int flags,
* check if it's already passed. In short, we need a sample.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- do_cpu_clock_sample(timer->it_clock, p, false, &val);
+ cpu_timer_sample(timer->it_clock, p, &val);
} else {
cpu_timer_sample_group(timer->it_clock, p, &val);
}
@@ -840,7 +840,7 @@ static void posix_cpu_timer_get(struct k_itimer *timer, struct itimerspec *itp)
* Sample the clock to take the difference with the expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
+ cpu_timer_sample(timer->it_clock, p, &now);
clear_dead = p->exit_state;
} else {
read_lock(&tasklist_lock);
@@ -1165,7 +1165,7 @@ void posix_cpu_timer_schedule(struct k_itimer *timer)
* Fetch the current sample and update the timer's expiry time.
*/
if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
- cpu_clock_sample(timer->it_clock, p, &now);
+ cpu_timer_sample(timer->it_clock, p, &now);
bump_cpu_timer(timer, now);
if (unlikely(p->exit_state)) {
clear_dead_task(timer, now);
--
1.7.1
prev parent reply other threads:[~2013-04-29 19:20 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-29 6:26 [PATCH 1/2] posix-cpu-timers: fix acounting delta_exec twice kosaki.motohiro
2013-04-29 6:26 ` [PATCH 2/2] posix-cpu-timers: fix wrong timer initialization kosaki.motohiro
2013-04-29 10:36 ` Peter Zijlstra
2013-04-29 17:53 ` KOSAKI Motohiro
2013-04-29 18:53 ` KOSAKI Motohiro
2013-04-29 19:17 ` [BUGFIX PATCH 3/2] posix-cpu-timers: check_thread_timers() uses task_sched_runtime() KOSAKI Motohiro
2013-04-29 19:18 ` [PATCH 4/2] sched: task_sched_runtime introduce micro optimization KOSAKI Motohiro
2013-04-29 19:19 ` [PATCH 5/2] posix-cpu-timers: cleanup cpu_{clock,timer}_sample{,_group} KOSAKI Motohiro
2013-04-29 19:20 ` KOSAKI Motohiro [this message]
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