Date: Tue, 19 May 2015 10:46:25 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Wang Nan <wangnan0@huawei.com>, a.p.zijlstra@chello.nl, paulus@samba.org,
        mingo@redhat.com, namhyung@kernel.org, lizefan@huawei.com,
        pi3orama@163.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH tip/perf/core] perf probe: Load map before glob matching
Message-ID: <20150519134625.GD13946@kernel.org>
References: <1431692084-46287-1-git-send-email-wangnan0@huawei.com>
 <55560DA1.6090909@hitachi.com>
 <20150515200703.GD17158@kernel.org>
 <555733D3.20805@hitachi.com>
 <20150518131717.GH15972@kernel.org>
 <555A78AA.1040406@hitachi.com>
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Em Tue, May 19, 2015 at 08:41:30AM +0900, Masami Hiramatsu escreveu:
> On 2015/05/18 22:17, Arnaldo Carvalho de Melo wrote:
> > Em Sat, May 16, 2015 at 09:10:59PM +0900, Masami Hiramatsu escreveu:
> >> On 2015/05/16 5:07, Arnaldo Carvalho de Melo wrote:
> >> OK, then I'm OK for this patch.
> > 
> > Ok, tranforming the above statement into an Acked-by, ok?
> 
> Yes, here is my ack :)
> 
> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> 
> 
> And also, I've found that including map__load() in map__for_each_symbol()
> is not good idea. Also I think map__for_each_symbol_by_name() should
> not call map__load(), since the "filter" argument will be ignored if
> the map is already loaded. This means that the iterated elements can
> be changed.
> So, obviously the map should be loaded before calling map__for_each_XXX.

Right, agreed with your comments, and that filter thing needs moving to
some other suitable place, like setting a filter at symbol system start,
etc.

- Arnaldo
 
> Thank you,
> 
> >  
> >> Thank you,
> >>
> >>>
> >>> - Arnaldo
> >>>  
> >>>> Thank you,
> >>>>
> >>>>>
> >>>>> This patch ensures map__load() is called before using
> >>>>> map__for_each_symbol().
> >>>>>
> >>>>> After this patch:
> >>>>>
> >>>>>  # /root/perf probe kmem_cache_free
> >>>>>   Added new event:
> >>>>>     probe:kmem_cache_free (on kmem_cache_free%return)
> >>>>>
> >>>>> You can now use it in all perf tools, such as:
> >>>>>
> >>>>>         perf record -e probe:kmem_cache_free -aR sleep 1
> >>>>>
> >>>>> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> >>>>> ---
> >>>>>  tools/perf/util/probe-event.c | 3 +++
> >>>>>  1 file changed, 3 insertions(+)
> >>>>>
> >>>>> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> >>>>> index 2399dc4..1faa1e6 100644
> >>>>> --- a/tools/perf/util/probe-event.c
> >>>>> +++ b/tools/perf/util/probe-event.c
> >>>>> @@ -2499,6 +2499,9 @@ static int find_probe_functions(struct map *map, char *name)
> >>>>>  	struct symbol *sym;
> >>>>>  	struct rb_node *tmp;
> >>>>>  
> >>>>> +	if (map__load(map, NULL) < 0)
> >>>>> +		return 0;
> >>>>> +
> >>>>>  	map__for_each_symbol(map, sym, tmp) {
> >>>>>  		if (strglobmatch(sym->name, name))
> >>>>>  			found++;
> >>>>>
> >>>>
> >> -- 
> >> 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.pt@hitachi.com
> > 
> 
> 
> -- 
> 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.pt@hitachi.com
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