RE: Re: [PATCH 28/31] perf probe: Init symbol as kprobe

[平松雅巳 / HIRAMATU，MASAMI]

> From: Arnaldo Carvalho de Melo [mailto:acme@xxxxxxxxxx]
> 
> Em Sat, Aug 29, 2015 at 04:22:02AM +0000, Wang Nan escreveu:
> > Before this patch, add_perf_probe_events() init symbol maps only for
> > uprobe if the first 'struct perf_probe_event' passed to it is a uprobe
> > event. This is a trick because 'perf probe''s command line syntax
> > constrains the first elements of the probe_event arrays must be kprobes
> > if there is one kprobe there.
> >
> > However, with the incoming BPF uprobe support, that constrain is not
> > hold since 'perf record' will also probe on k/u probes through BPF
> > object, and is possible to pass an array with kprobe but the first
> > element is uprobe.
> >
> > This patch init symbol maps for kprobes even if all of events are
> > uprobes, because the extra cost should be small enough.
> 
> Masami, are you Ok with this one?

Yeah, looks OK for me ! :)

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>

Thanks!

> 
> - Arnaldo
> 
> > Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
> > Cc: Alexei Starovoitov <ast@xxxxxxxxxxxx>
> > Cc: Brendan Gregg <brendan.d.gregg@xxxxxxxxx>
> > Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> > Cc: David Ahern <dsahern@xxxxxxxxx>
> > Cc: He Kuang <hekuang@xxxxxxxxxx>
> > Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> > Cc: Kaixu Xia <xiakaixu@xxxxxxxxxx>
> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> > Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> > Cc: Paul Mackerras <paulus@xxxxxxxxx>
> > Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> > Cc: Zefan Li <lizefan@xxxxxxxxxx>
> > Cc: pi3orama@xxxxxxx
> > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > Link: http://lkml.kernel.org/n/1436445342-1402-39-git-send-email-wangnan0@xxxxxxxxxx
> > ---
> >  tools/perf/util/probe-event.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> > index e720913..b94a8d7 100644
> > --- a/tools/perf/util/probe-event.c
> > +++ b/tools/perf/util/probe-event.c
> > @@ -2789,7 +2789,7 @@ int add_perf_probe_events(struct perf_probe_event *pevs, int npevs,
> >  {
> >  	int i, ret;
> >
> > -	ret = init_symbol_maps(pevs->uprobes);
> > +	ret = init_symbol_maps(false);
> >  	if (ret < 0)
> >  		return ret;
> >
> > --
> > 2.1.0
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