On Thu, Jan 23, 2014 at 12:19:56PM +0530, Sujith Manoharan wrote: > Hi, > > I am trying to use perf lock and am not sure if > the results are correct (the bad rate is 98 %). > > Is this expected behavior ?
some of the kernel lock types do not follow the: acquire contended acuired release lock state machine, like rcu or spin locks.. and thats what caused most of the bad rates in my tests. I was recently working on some changes for lock tracing, what stats are you interested in? jirka > > root@linux-test ~# perf --version > perf version 3.12.0 > > root@linux-test ~# perf lock record cat /etc/issue > Arch Linux \r (\l) > > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.356 MB perf.data (~15533 samples) ] > root@linux-test ~# perf lock report > Name acquired contended total wait (ns) max wait (ns) > min wait (ns) > > &cpuctx_lock 0 0 0 0 > 0 > &sig->cred_guard... 0 0 0 0 > 0 > > === output for debug=== > > bad: 153, total: 155 > bad rate: 98.709677 % > histogram of events caused bad sequence > acquire: 1 > acquired: 0 > contended: 0 > release: 152 > > I am using the wireless-testing kernel: > root@linux-test ~# uname -a > Linux linux-test 3.13.0-wl-debug #197 SMP PREEMPT Tue Jan 21 03:19:43 IST > 2014 x86_64 GNU/Linux > > lockdep is enabled: > root@linux-test ~# zgrep -i lockdep /proc/config.gz > CONFIG_LOCKDEP_SUPPORT=y > CONFIG_LOCKDEP=y > # CONFIG_DEBUG_LOCKDEP is not set > > > Sujith > -- > To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
