On Wed, 2007-04-04 at 13:43 -0700, Andrew Morton wrote: > On Wed, 04 Apr 2007 12:50:15 -0700 > john stultz <[EMAIL PROTECTED]> wrote: > > > In debugging a problem w/ the -rt tree, I noticed that on systems that > > mark the tsc as unstable before it is registered, the TSC would still be > > selected and used for a short period of time. Digging in it looks to be > > a result of the mix of the clocksource list changes and my clocksource > > initialization changes. > > > > With the -rt tree, using a bad TSC, even for a short period of time can > > results in a hang at boot. I was not able to reproduce this hang w/ > > mainline, but I'm not completely certain that someone won't trip on it. > > > > This patch resolves the issue by initializing the jiffies clocksource > > earlier so a bad TSC won't get selected just because nothing else is yet > > registered. > > > > thanks > > -john > > > > Signed-off-by: John Stultz <[EMAIL PROTECTED]> > > > > diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c > > index 3be8da8..4c256fd 100644 > > --- a/kernel/time/jiffies.c > > +++ b/kernel/time/jiffies.c > > @@ -69,4 +69,4 @@ static int __init init_jiffies_clocksour > > return clocksource_register(&clocksource_jiffies); > > } > > > > -module_init(init_jiffies_clocksource); > > +core_initcall(init_jiffies_clocksource); > > Do you think this is needed in 2.6.21? > > If so: worrisome. Startup ordering issues are fragile and tricky. Time > management is fragile and tricky. The combination of the two doesn't get > any better ;)
Its likely low-risk, however I'm pretty cautious this close to release. > An option would be to test it in 2.6.22-rcX for a while, then backport to > 2.6.21.x. I'm fine with this (also getting it into the next -mm would help). But I'd defer to others with stronger opinions. thanks -john - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
