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

From	平松雅巳 / HIRAMATU，MASAMI <masami.hiramatsu.pt@hitachi.com>
Newsgroups	linux.kernel
Subject	RE: Re: [PATCH 28/31] perf probe: Init symbol as kprobe
Date	2015-09-02 03:40 +0200
Message-ID	<q45bQ-7bH-11@gated-at.bofh.it> (permalink)
References	<q2FWa-7Rj-5@gated-at.bofh.it> <q2FWa-7Rj-27@gated-at.bofh.it> <q40ca-7Z-13@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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> From: Arnaldo Carvalho de Melo [mailto:acme@redhat.com]
> 
> 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@hitachi.com>

Thanks!

> 
> - Arnaldo
> 
> > Signed-off-by: Wang Nan <wangnan0@huawei.com>
> > Cc: Alexei Starovoitov <ast@plumgrid.com>
> > Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
> > Cc: Daniel Borkmann <daniel@iogearbox.net>
> > Cc: David Ahern <dsahern@gmail.com>
> > Cc: He Kuang <hekuang@huawei.com>
> > Cc: Jiri Olsa <jolsa@kernel.org>
> > Cc: Kaixu Xia <xiakaixu@huawei.com>
> > Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> > Cc: Namhyung Kim <namhyung@kernel.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> > Cc: Zefan Li <lizefan@huawei.com>
> > Cc: pi3orama@163.com
> > Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> > Link: http://lkml.kernel.org/n/1436445342-1402-39-git-send-email-wangnan0@huawei.com
> > ---
> >  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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[PATCH 28/31] perf probe: Init symbol as kprobe Wang Nan <wangnan0@huawei.com> - 2015-08-29 06:30 +0200
  Re: [PATCH 28/31] perf probe: Init symbol as kprobe Arnaldo Carvalho de Melo <acme@redhat.com> - 2015-09-01 22:20 +0200
    Re: [PATCH 28/31] perf probe: Init symbol as kprobe "Wangnan (F)" <wangnan0@huawei.com> - 2015-09-02 03:30 +0200
    RE: Re: [PATCH 28/31] perf probe: Init symbol as kprobe 平松雅巳 / HIRAMATU，MASAMI   <masami.hiramatsu.pt@hitachi.com> - 2015-09-02 03:40 +0200

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