Re: 2.6.29 -mm merge plans

[Andi Kleen]

On Thu, Jan 08, 2009 at 02:24:55PM +0100, Pavel Machek wrote:
> On Wed 2009-01-07 03:57:25, Andi Kleen wrote:
> > > sys_sync B which is invoked *after* sys_sync caller A should not
> > > return before A. If you didn't have a global lock, they'd tend to
> > > block one another's pages anyway. I think it's OK.
> > 
> > It means that you cannot reboot because reboot does sync.
> > What happens when the sync gets stuck somewhere on a really
> > slow device?
> 
> And what do you propose? Silently corrupt data on the slow device?

Yes not writing is better than being unable to reboot.

There should be always a timeout at least for the reboot case.

Consider it from a uptime perspective: if something is really
screwed up (and that happens sometimes; classical example 
was the IO stack getting hung up forever in error handling
loops) the only way to get running again is to reboot and try again.

-Andi
-- 
ak@xxxxxxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/