Messages in this thread | | | Date | Sat, 13 Jan 2007 18:53:44 +1100 | From | Nick Piggin <> | Subject | Re: High lock spin time for zone->lru_lock under extreme conditions |
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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 >>is, >>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?
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