[lkml]   [2007]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: High lock spin time for zone->lru_lock under extreme conditions
Ravikiran G Thirumalai wrote:
> On Sat, Jan 13, 2007 at 03:39:45PM +1100, Nick Piggin wrote:

>>What is the "CS time"?
> Critical Section :). This is the maximal time interval I measured from
> t2 above to the time point we release the spin lock. This is the hold
> time I guess.
>>It would be interesting to know how long the maximal lru_lock *hold* time
>>which could give us a better indication of whether it is a hardware problem.
>>For example, if the maximum hold time is 10ms, that it might indicate a
>>hardware fairness problem.
> The maximal hold time was about 3s.

Well then it doesn't seem very surprising that this could cause a 30s wait
time for one CPU in a 16 core system, regardless of fairness.

I guess most of the contention, and the lock hold times are coming from
vmscan? Do you know exactly which critical sections are the culprits?

SUSE Labs, Novell Inc.
Send instant messages to your online friends

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2007-01-13 10:01    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean