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Date: Tue, 1 Jun 2010 22:05:24 +0200
From: Stephane Eranian <eranian@...gle.com>
To: Arnaldo Carvalho de Melo <acme@...radead.org>
Cc: linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
perfmon2-devel@...ts.sf.net, eranian@...il.com,
"David S. Miller" <davem@...emloft.net>,
Frédéric Weisbecker <fweisbec@...il.com>,
Mike Galbraith <efault@....de>,
Paul Mackerras <paulus@...ba.org>,
Peter Zijlstra <peterz@...radead.org>,
Tom Zanussi <tzanussi@...il.com>
Subject: Re: [BUG] perf: buildid not managed properly when cmd path is
relative
Hi,
You patch does seem to fix the problem.
However, I think there may be another issue, maybe
caused by the patch.
If you monitor a program WITHOUT buildids, and you run
$ perf record tmp/foo
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.077 MB perf.data (~3370 samples) ]
$ ./perf buildid-list
86200ab2bca285344a55156a079debbbe172bcc5 [kernel.kallsyms]
foo does not appear, yet we know it got samples.
$ ./perf buildid-list --with-hits
86200ab2bca285344a55156a079debbbe172bcc5 [kernel.kallsyms]
0000000000000000000000000000000000000000 /home/eranian/tmp/foo
With the --with-hits option, I get more output than without.Supposedly
no option means 'prints all entries', including those with hits or
without buildids.
On Tue, Jun 1, 2010 at 8:38 PM, Arnaldo Carvalho de Melo
<acme@...radead.org> wrote:
> Em Thu, May 27, 2010 at 03:46:16PM +0200, Stephane Eranian escreveu:
>> I ran into another problem while running more tests with perf record,
>> perf buildid-list.
>
>> I do the following:
>
>> $ perf record foo/noploop 5 ; perf buildid-list
>> 54b1e7cc3cf52e0db255aab44ce7538eb62655b8 [kernel.kallsyms]
>> 875ae61623e89f408b425ca0486a9ec99e3ac73e
>> /home/eranian/perfmon/official/tip/build/tools/perf/foo/noploop
>>
>> I know I have samples in noploop:
>> $ perf report -D
>> 0x10a0 [0x20]: PERF_RECORD_SAMPLE(IP, 2): 14721/14721: 0x4006d6 period: 2351576
>> ... thread: noploop:14721
>> ...... dso: ./foo/noploop
>
>> But if I ask with buildid-list (like per-archive is doing) then I get:
>> $ perf buildid-list --with-hits
>> 54b1e7cc3cf52e0db255aab44ce7538eb62655b8 [kernel.kallsyms]
>> 0000000000000000000000000000000000000000 ./foo/noploop
>
>> The builid is bogus for noploop and it is relative path not full anymore.
>
> Hi Stephane,
>
> Can you please try the following patch?
>
> Thanks in advance,
>
> - Arnaldo
>
> From 9d146ff3c994634c529396442a4a96b0e58809e2 Mon Sep 17 00:00:00 2001
> From: Arnaldo Carvalho de Melo <acme@...hat.com>
> Date: Tue, 1 Jun 2010 12:37:05 -0300
> Subject: [PATCH 1/1] perf buildid-list: Fix --with-hits event processing
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
>
> When we use plain 'perf buildid-list' we use only what is in the buildid
> table in the perf.data header. And those have absolute pathnames because
> at 'perf record' time we used __perf_session__process_events and that
> doesn't sets up the path shortening code in map__new() that happens if
> symbol_conf.full_paths is false, the default.
>
> On the other hand, when we use 'perf buildid-list --with-hits' we
> process all the events using perf_session__process_events, adding
> entries to the global DSO list _after_ removing the current directory
> from the DSO name, for presentation purposes.
>
> Because of that we end up having two entries in the DSO list when
> recording events for binaries using relative pathnames.
>
> Fix it minimally by setting symbol_conf.full_paths to true when marking
> the DSOs with hits in 'perf buildid-list --with-hits', as used by 'perf
> archive'
>
> Right fix longer term is to shorten the path only at presentation time.
> Will be done for 2.6.36.
>
> Reported-by: Stephane Eranian <eranian@...gle.com>
> Cc: David S. Miller <davem@...emloft.net>
> Cc: Frédéric Weisbecker <fweisbec@...il.com>
> Cc: Ingo Molnar <mingo@...e.hu>
> Cc: Mike Galbraith <efault@....de>
> Cc: Paul Mackerras <paulus@...ba.org>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Stephane Eranian <eranian@...gle.com>
> Cc: Tom Zanussi <tzanussi@...il.com>
> LKML-Reference: <new-submission>
> Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
> ---
> tools/perf/builtin-buildid-list.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
> index 44a47e1..9989072 100644
> --- a/tools/perf/builtin-buildid-list.c
> +++ b/tools/perf/builtin-buildid-list.c
> @@ -43,8 +43,10 @@ static int __cmd_buildid_list(void)
> if (session == NULL)
> return -1;
>
> - if (with_hits)
> + if (with_hits) {
> + symbol_conf.full_paths = true;
> perf_session__process_events(session, &build_id__mark_dso_hit_ops);
> + }
>
> perf_session__fprintf_dsos_buildid(session, stdout, with_hits);
>
> --
> 1.6.5.2
>
>
--
Stephane Eranian | EMEA Software Engineering
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