lkml.org 
[lkml]   [2007]   [Jan]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    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
    >>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?

    --
    SUSE Labs, Novell Inc.
    Send instant messages to your online friends http://au.messenger.yahoo.com

    -
    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: 2007-01-13 10:01    [W:0.023 / U:0.732 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site