Messages in this thread | | | Date | Thu, 22 Apr 2010 15:06:25 +0800 | From | Yong Zhang <> | Subject | Re: Lockdep usage |
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On Wed, Apr 21, 2010 at 11:26:07PM -0700, Darren Hart wrote: > I'm having some trouble with lockstat. I've enabled > CONFIG_LOCK_STATS and then run the following commands to collect the > lock statistics for the futex_lock test case. I expect this test > case to generate a fair amount of contention on the futex hash > bucket locks, but they don't show up in the stats (in fact, nothing > shows up in the stats). I have seen much longer lock_stat files when > I forgot to clear them before the test, but no hb locks showed up > there either. > > Is my usage below incorrect? Do I have to somehow annotate the > hb->lock in order for lockstat to track it?
IMHO, you don't need to do that.
> lock.lockstat; echo 0 > /proc/sys/kernel/lock_stat > futex_lock: Measure FUTEX_LOCK operations per second > Arguments: iterations=10000000 threads=256 adaptive=no > period=1000 duty-cycle=20% > Result: 731 Kiter/s > > # cat lock.lockstat > lock_stat version 0.3 > *WARNING* lock debugging disabled!! - possibly due to a lockdep warning
This means lockdep has detect there is something wrong. Can you show your 'dmesg'?
Thanks, Yong
> ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > class name con-bounces > contentions waittime-min waittime-max waittime-total > acq-bounces acquisitions holdtime-min holdtime-max > holdtime-total > ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- > > # > > Thanks, > > -- > Darren Hart > IBM Linux Technology Center > Real-Time Linux Team > -- > 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/
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