From: john stultz <johnstul@us.ibm.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: lkml <linux-kernel@vger.kernel.org>,
Darren Hart <dvhltc@us.ibm.com>, Paul Clarke <pacman@us.ibm.com>
Subject: Re: [RFC][PATCH -rt] Handling delayed clocksource watchdog timer
Date: Thu, 22 Jul 2010 20:34:14 -0700 [thread overview]
Message-ID: <1279856054.2442.60.camel@localhost.localdomain> (raw)
In-Reply-To: <1279854789.2442.54.camel@localhost.localdomain>
On Thu, 2010-07-22 at 20:13 -0700, john stultz wrote:
> diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
> index 0e98497..a91e7ba 100644
> --- a/kernel/time/clocksource.c
> +++ b/kernel/time/clocksource.c
> @@ -280,7 +280,8 @@ static void clocksource_watchdog(unsigned long data)
> cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
> cs->mask, cs->mult, cs->shift);
> cs->wd_last = csnow;
> - if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
> + if (jiffies - watchdog_timer.expires > 4*WATCHDOG_INTERVAL) &&
> + (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
> clocksource_unstable(cs, cs_nsec - wd_nsec);
> continue;
> }
Bah.
Was testing with this patch and just realized it has a thinko
(greater-than instead of less-than).
Should be:
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 0e98497..a91e7ba 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -280,7 +280,8 @@ static void clocksource_watchdog(unsigned long data)
cs_nsec = clocksource_cyc2ns((csnow - cs->wd_last) &
cs->mask, cs->mult, cs->shift);
cs->wd_last = csnow;
- if (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
+ if (jiffies - watchdog_timer.expires < 4*WATCHDOG_INTERVAL) &&
+ (abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) {
clocksource_unstable(cs, cs_nsec - wd_nsec);
continue;
}
prev parent reply other threads:[~2010-07-23 3:34 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-23 3:13 john stultz
2010-07-23 3:34 ` john stultz [this message]
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