On 2015/06/30 15:44, Benjamin King wrote: > On Mon, Jun 29, 2015 at 12:00:38PM -0300, Arnaldo Carvalho de Melo wrote: >> Em Sun, Jun 28, 2015 at 05:46:51PM +0200, Benjamin King escreveu: >>>> Is there a trick to getting perf to probe a user-level address without >>>> debuginfo? Eg (on Linux 4.0): >>>> [...] >>>> I can do this using ftrace ok, eg, "p:tick_0x583 /root/tick:0x583" >>>> works. Thanks, >>> >>> Not quite what you have asked for, but you can add the probe via ftrace and >>> then use it from perf. Probes from /sys/kernel/debug/tracing/uprobe_events >>> will show up in 'perf list' as well. >> >> Masami, >> >> Is this already possible? > > Hi Arnaldo, > > for me this works in 3.19.0. I'm using the attached script to help me add > probes to /sys/kernel/debug/tracing/uprobe_events which I can then see with > 'sudo perf list' and use from the other perf subcommands. Tracing arguments is > also working fine:
Yeah, perf probe should be able to do the same thing without debuginfo. If not, there must be a bug. :( > > --- snip --- > $ uprobe /lib/x86_64-linux-gnu/libc.so.6 malloc %di > $ sudo perf stat -e uprobes:* ls > ... > Performance counter stats for 'ls': > ... > 218 uprobes:malloc_1 > > $ sudo perf record -euprobes:malloc_1 ls >/dev/null 2>&1 > $ sudo perf script > ls 21084 [003] 10825.526815: uprobes:malloc_1: (7f772bfc2700) > arg1=0x238 > ls 21084 [003] 10825.526917: uprobes:malloc_1: (7f772bfc2700) > arg1=0x238 > ls 21084 [003] 10825.526968: uprobes:malloc_1: (7f772bfc2700) > arg1=0x78 > ls 21084 [003] 10825.527089: uprobes:malloc_1: (7f772bfc2700) > arg1=0x5 > ls 21084 [003] 10825.527132: uprobes:malloc_1: (7f772bfc2700) > arg1=0x78 > ... > --- snip --- > > This is superuseful to me, so thank you all for working on perf! > > I failed to manage placing proper probes in C++-Code with perf probe, so I > hacked the script together after reading Brendans ftrace article on LWN. Hmm, that must be a bug, so it should be fixed. Thank you! -- Masami HIRAMATSU Linux Technology Research Center, System Productivity Research Dept. Center for Technology Innovation - Systems Engineering Hitachi, Ltd., Research & Development Group E-mail: masami.hiramatsu...@hitachi.com -- 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
