* Oleg Nesterov <o...@redhat.com> [2013-02-04 16:18:50]: > On 02/04, Srikar Dronamraju wrote: > > > > * Oleg Nesterov <o...@redhat.com> [2013-01-31 20:18:32]: > > > > > Move tu->nhit++ from uprobe_trace_func() to uprobe_dispatcher(). > > > > > > ->nhit counts how many time we hit the breakpoint inserted by this > > > uprobe, we do not want to loose this info if uprobe was enabled by > > > sys_perf_event_open(). > > > > > > > Though I dont see a problem with this change, It seems unnecessary for > > me. > > > > Info from nhits is mostly for /sys/kernel/debug/tracing/uprobe_profile > > It is only for uprobe_profile, yes, and it is useful. Why should we hide > this info if this uprobe is used by perf?
Fine with me. Steve, Masami, Do you have comments/suggestions on this. (Since kprobe_profile just accounts for kprobetracer and doesnt account for perf record.) May we should make a similar change in kprobetracer to keep things similar. -- Thanks and Regards Srikar Dronamraju > > > I am not sure how sys_perf_event_open() is making use of this? > > I hope I'll send the final series today. From the changelog of the patch > which actually turns the filtering on: > > Testing: > > # perf probe -x /lib/libc.so.6 syscall > > # perl -e 'syscall -1 while 1' & > [1] 530 > > # perf record -e probe_libc:syscall perl -e 'syscall -1 for > 1..10; sleep 1' > > # perf report --show-total-period > 100.00% 10 perl libc-2.8.so [.] > syscall > > Before this patch: > > # cat /sys/kernel/debug/tracing/uprobe_profile > /lib/libc.so.6 syscall 79291 > > A huge ->nrhit == 79291 reflects the fact that the background process > 530 constantly hits this breakpoint too, even if doesn't contribute to > the output. > > After the patch: > > # cat /sys/kernel/debug/tracing/uprobe_profile > /lib/libc.so.6 syscall 10 > > This shows that only the target process was punished by int3. > > Oleg. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
