Messages in this thread | | | Date | Thu, 25 Feb 2016 09:49:24 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [RFC PATCH 2/2] perf script: Print bpf-output events in 'perf script' |
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Em Thu, Feb 25, 2016 at 12:11:11PM +0800, Wangnan (F) escreveu: > > > On 2016/2/24 23:19, Arnaldo Carvalho de Melo wrote: > >Em Wed, Feb 24, 2016 at 11:20:45AM +0000, Wang Nan escreveu: > >>This patch allows 'perf script' output messages from BPF program. > >>For example, use test_bpf_output_3.c at the end of this commit > >>message, > >> > >> # ./perf record -e bpf-output/no-inherit,name=evt/ \ > >> -e ./test_bpf_output_3.c/map:channel.event=evt/ \ > >> usleep 100000 > >Trying to test this with 'perf trace', i.e. to shortcircuit record + > >analysis: > > > >[root@jouet bpf]# perf trace -a --ev bpf-output/no-inherit,name=evt/ --ev ./test_bpf_output_3.c/map:channel.event=evt/ --ev 'perf_bpf_probe:*' usleep 100000 > >Failed to set filter "common_pid != 23954" on event evt with 22 (Invalid argument) > > > >Can't we set tracepoint filters on these events?
> No we can't. filters can only be set to tracepoint events, but > bpf-output is a software event.
Gack, should've checked that, I somehow thought that it was a tracepoint event of some sort.
> In addition, you don't need > ... --ev 'perf_bpf_probe:*' ... > > because they should be already collected by '--ev ./test_bpf_output_3.c'.
Right, that was me trying to be clever 8-)
> You don't see them because the two kprobe events are filtered out by > BPF program. See 'return 0' in func.
Thanks for reminding about this part...
> Thank you.
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