lkml.org 
[lkml]   [2006]   [Oct]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [RFC] Avoid PIT SMP lockups
Date

> It might only happen with SMP because the difficulty of getting good
> enough TSC / timer IRQ synchronization during boot increases
> exponentially with SMP configurations. And it might pass 10% of the time
> because you were lucky enough not to fire off another timer interrupt yet.

We have the same problem with NMI watchdog events unfortunately.
Need to call something in the nmi watchdog code to make sure it is
not renewed and then reenabled.
Or maybe it's better to figure out a way that yields atomic patches.

I think the best way is to make sure all alternative() patches
are always done before the code can be ever executed - this
means doing it very early for the main kernel. The only exception
would be the LOCK prefix patching, which should be atomic.

iirc there was some more patching except lock prefixes going on for
SMP<->UP transisitions, but last time I checked they didn't look
particularly useful and could be probably eliminated.

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

\
 
 \ /
  Last update: 2006-10-17 00:43    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site