Messages in this thread | | | Date | Wed, 28 Feb 2018 04:06:17 -0800 | From | Srikar Dronamraju <> | Subject | Re: [RFC 0/4] trace_uprobe: Support SDT markers having semaphore |
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* Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> [2018-02-28 13:23:41]:
> # readelf -n ./tick > Provider: tick > Name: loop2 > ... Semaphore: 0x0000000010020036 > > # readelf -SW ./tick | grep probes > [25] .probes PROGBITS 0000000010020034 010034 > > > Semaphore offset is 0x10036. I don't have educated 'perf probe' > about semaphore. So instead of using 'perf probe' command, I'm > manually adding entry in the <tracefs>/uprobe_events file. > Special char * denotes semaphore offset. > > > # echo "p:sdt_tick/loop2 /tmp/tick:0x6e4 *0x10036" > uprobe_events > > # perf stat -e sdt_tick:loop2 -- /tmp/tick > hi: 0 > hi: 1 > hi: 2 > hi: 3 > ^C > Performance counter stats for '/tmp/tick': > 4 sdt_tick:loop2 > 3.359047827 seconds time elapsed > > > Feedback? > > TODO: > - Educate perf tool about semaphore. >
Is it possible to extend perf buildcache with a new option to work with semaphore?
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