lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20180228120617.GA63063@linux.vnet.ibm.com> Date: Wed, 28 Feb 2018 04:06:17 -0800 From: Srikar Dronamraju <srikar@...ux.vnet.ibm.com> To: Ravi Bangoria <ravi.bangoria@...ux.vnet.ibm.com> Cc: peterz@...radead.org, mingo@...hat.com, acme@...nel.org, alexander.shishkin@...ux.intel.com, jolsa@...hat.com, namhyung@...nel.org, linux-kernel@...r.kernel.org, rostedt@...dmis.org, mhiramat@...nel.org, ananth@...ux.vnet.ibm.com, naveen.n.rao@...ux.vnet.ibm.com, oleg@...hat.com Subject: Re: [RFC 0/4] trace_uprobe: Support SDT markers having semaphore * Ravi Bangoria <ravi.bangoria@...ux.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?
Powered by blists - more mailing lists