On Sat, Sep 04, 2010 at 05:58:40PM +1000, Dave Chinner wrote: > On Fri, Sep 03, 2010 at 08:21:01PM -0700, Andrew Morton wrote: > > On Sat, 4 Sep 2010 12:25:45 +1000 Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > > Still, given the improvements in performance from this patchset, > > > I'd say inclusion is a no-braniner.... > > > > OK, thanks. > > > > It'd be interesting to check the IPI frequency with and without - > > /proc/interrupts "CAL" field. Presumably it went down a lot. > > Maybe I suspected you would ask for this. I happened to dump > /proc/interrupts after the livelock run finished, so you're in > luck :) .... > > livelock: 59458 58367 58559 59493 59614 57970 59060 58207 > > So the livelock case tends to indicate roughly 40,000 more IPI > interrupts per CPU occurred. The livelock occurred for close to 5 > minutes, so that's roughly 130 IPIs per second per CPU.... And just to confuse the issue further, I just had a livelock on a vanilla kernel that did *not* cause the CAL counts to increase. Hence it appears that the IPI storms are not the cause of the livelocks І'm triggering.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>