* [PATCH 1/5] hrtimer_nanosleep: use -EINTR, not -ERESTARTNOHAND
@ 2008-02-01 13:37 Oleg Nesterov
2008-02-01 13:50 ` Thomas Gleixner
0 siblings, 1 reply; 3+ messages in thread
From: Oleg Nesterov @ 2008-02-01 13:37 UTC (permalink / raw)
To: Andrew Morton, Thomas Gleixner
Cc: Alexey Dobriyan, Ingo Molnar, Pavel Emelyanov, Peter Zijlstra,
linux-kernel
hrtimer_nanosleep:
/* Absolute timers do not update the rmtp value and restart: */
return -ERESTARTNOHAND;
This is not right, -ERESTARTNOHAND means we will do restart if there is no
in fact pending signal, and worse, this restart will use the same unchanged
"__user *rmtp" parameter.
Use -EINTR instead.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
--- MM/kernel/hrtimer.c~HRT_RMTP~ 2008-01-27 17:07:39.000000000 +0300
+++ MM/kernel/hrtimer.c~HRT_RMTP 2008-02-01 13:43:52.000000000 +0300
@@ -1359,7 +1359,7 @@ long hrtimer_nanosleep(struct timespec *
/* Absolute timers do not update the rmtp value and restart: */
if (mode == HRTIMER_MODE_ABS)
- return -ERESTARTNOHAND;
+ return -EINTR;
if (rmtp) {
rem = ktime_sub(t.timer.expires, t.timer.base->get_time());
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 1/5] hrtimer_nanosleep: use -EINTR, not -ERESTARTNOHAND
2008-02-01 13:37 [PATCH 1/5] hrtimer_nanosleep: use -EINTR, not -ERESTARTNOHAND Oleg Nesterov
@ 2008-02-01 13:50 ` Thomas Gleixner
2008-02-01 14:20 ` Oleg Nesterov
0 siblings, 1 reply; 3+ messages in thread
From: Thomas Gleixner @ 2008-02-01 13:50 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Andrew Morton, Alexey Dobriyan, Ingo Molnar, Pavel Emelyanov,
Peter Zijlstra, linux-kernel
On Fri, 1 Feb 2008, Oleg Nesterov wrote:
> hrtimer_nanosleep:
>
> /* Absolute timers do not update the rmtp value and restart: */
> return -ERESTARTNOHAND;
>
> This is not right, -ERESTARTNOHAND means we will do restart if there is no
> in fact pending signal, and worse, this restart will use the same unchanged
> "__user *rmtp" parameter.
-ERESTARTNOHAND is safe here. We want to restart the timer.
The rmtp problem is separate, but that's addressed by your follow up changes.
Thanks,
tglx
> Use -EINTR instead.
>
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
>
> --- MM/kernel/hrtimer.c~HRT_RMTP~ 2008-01-27 17:07:39.000000000 +0300
> +++ MM/kernel/hrtimer.c~HRT_RMTP 2008-02-01 13:43:52.000000000 +0300
> @@ -1359,7 +1359,7 @@ long hrtimer_nanosleep(struct timespec *
>
> /* Absolute timers do not update the rmtp value and restart: */
> if (mode == HRTIMER_MODE_ABS)
> - return -ERESTARTNOHAND;
> + return -EINTR;
>
> if (rmtp) {
> rem = ktime_sub(t.timer.expires, t.timer.base->get_time());
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH 1/5] hrtimer_nanosleep: use -EINTR, not -ERESTARTNOHAND
2008-02-01 13:50 ` Thomas Gleixner
@ 2008-02-01 14:20 ` Oleg Nesterov
0 siblings, 0 replies; 3+ messages in thread
From: Oleg Nesterov @ 2008-02-01 14:20 UTC (permalink / raw)
To: Thomas Gleixner
Cc: Andrew Morton, Alexey Dobriyan, Ingo Molnar, Pavel Emelyanov,
Peter Zijlstra, linux-kernel
On 02/01, Thomas Gleixner wrote:
>
> On Fri, 1 Feb 2008, Oleg Nesterov wrote:
>
> > hrtimer_nanosleep:
> >
> > /* Absolute timers do not update the rmtp value and restart: */
> > return -ERESTARTNOHAND;
> >
> > This is not right, -ERESTARTNOHAND means we will do restart if there is no
> > in fact pending signal, and worse, this restart will use the same unchanged
> > "__user *rmtp" parameter.
>
> -ERESTARTNOHAND is safe here. We want to restart the timer.
Ah. I was greatly confused by the comment, it says "do not ... restart",
now I understand what this _actually_ means.
And yes, I was wrong. If restart is wanted, it is safe to use the original
*rqtp, the timer is HRTIMER_MODE_ABS.
Thanks Thomas!
Andrew, please ignore this patch.
Oleg.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2008-02-01 14:17 UTC | newest]
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2008-02-01 13:37 [PATCH 1/5] hrtimer_nanosleep: use -EINTR, not -ERESTARTNOHAND Oleg Nesterov
2008-02-01 13:50 ` Thomas Gleixner
2008-02-01 14:20 ` Oleg Nesterov
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