linux-kernel - Re: [PATCH v2 0/6] perf tools: Use SIGUSR2 control data dumpping

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Message-ID: <20160415001939.GL9056@kernel.org>
Date:	Thu, 14 Apr 2016 21:19:39 -0300
From:	Arnaldo Carvalho de Melo <acme@...nel.org>
To:	Wang Nan <wangnan0@...wei.com>
Cc:	linux-kernel@...r.kernel.org, pi3orama@....com,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Zefan Li <lizefan@...wei.com>, He Kuang <hekuang@...wei.com>
Subject: Re: [PATCH v2 0/6] perf tools: Use SIGUSR2 control data dumpping

Em Thu, Apr 14, 2016 at 02:21:59PM +0000, Wang Nan escreveu:
> This patch set is based on perf/core.
> 
> v1 -> v2: Fix a bug which triggers output switching without
>           '--switch-output' provided.
> 
> Patch 5/10 in v1 has a bug: with following cmdline:
>  # perf record -e intel_bts// --per-thread --snapshot -p 13588

Ok, I moved the trigger stuff to a new file, util/trigger.h and added
missing man page entries, pushed to acme/perf/core, please take a look
if all is well before I push this to Ingo, tomorrow.

Adrian/others, if you can, please take a look.

- Arnaldo
 
> Sending 'SIGUSR2' to perf triggers output switching, which us
> undesirable. The reason is in signal handler perf doesn't consider if
> user provided --switch-output explicitly.
> 
> With this patchset applied:
> 
>  # /perf record --switch-output -e intel_bts// --per-thread --snapshot -p 13588 &
>  [1] 15116
>  # kill -s SIGUSR2 15116
>  # [ perf record: dump data: Woken up 5 times ]
>  [ perf record: Dump perf.data.2016041506170000 ]
>  
>  # kill -s SIGUSR2 15116
>  # [ perf record: dump data: Woken up 3 times ]
>  [ perf record: Dump perf.data.2016041506170447 ]
>  
>  # fg
>  /perf record --switch-output -e intel_bts// --per-thread --snapshot -p 13588
>  ^C[ perf record: Woken up 3 times to write data ]
>  [ perf record: Dump perf.data.2016041506170785 ]
>  [ perf record: Captured and wrote 0.012 MB perf.data.<timestamp> ]
>  
>  # ls -l ./perf.data*
>  -rw------- 1 root root 4212888 Apr 15 06:17 ./perf.data.2016041506170000
>  -rw------- 1 root root 4212704 Apr 15 06:17 ./perf.data.2016041506170447
>  -rw------- 1 root root   18368 Apr 15 06:17 ./perf.data.2016041506170785
> 
> The first 2 perf.data works fine. The final one has no samples.
> 
> And:
>  # rm ./perf.data*
>  # /perf record -e intel_bts// --per-thread --snapshot -p 13588 &
>  [1] 15396
>  # kill -s SIGUSR2 15396
>  # kill -s SIGUSR2 15396
>  # fg
>  /perf record -e intel_bts// --per-thread --snapshot -p 13588
>  ^C[ perf record: Woken up 9 times to write data ]
>  [ perf record: Captured and wrote 8.012 MB perf.data ]
>  
>  # ls -l ./perf.data*
>  -rw------- 1 root root 8417552 Apr 15 06:20 ./perf.data
> 
> (In v1, the second test trigger output switching incorrectly)
> 
> Patch 1-2/6 in this patchset makes switch output trigger similar to
> auxtrace snapshot trigger. Patch 1/6 introduces a 'trigger' class for
> them. It would be better to merge patch 1/6 with commit c0bdc1c ("perf
> record: Turns auxtrace_snapshot_enable into 3 states"). However, Ingo
> has collected that commit, so make it a separated patch.
> 
> Signed-off-by: Wang Nan <wangnan0@...wei.com>
> Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
> Cc: Adrian Hunter <adrian.hunter@...el.com>
> Cc: Jiri Olsa <jolsa@...nel.org>
> Cc: Masami Hiramatsu <mhiramat@...nel.org>
> Cc: Namhyung Kim <namhyung@...nel.org>
> Cc: Zefan Li <lizefan@...wei.com>
> Cc: pi3orama@....com
> Cc: He Kuang <hekuang@...wei.com>
> 
> Wang Nan (6):
>   perf tools: Extrace trigger class from auxtrace_snapshot
>   perf record: Split output into multiple files via '--switch-output'
>   perf record: Force enable --timestamp-filename when --switch-output is
>     provided
>   perf record: Disable buildid cache options by default in switch output
>     mode
>   perf record: Re-synthesize tracking events after output switching
>   perf record: Generate tracking events for process forked by perf
> 
>  tools/perf/builtin-record.c | 147 +++++++++++++++++++++++++++++++-------------
>  tools/perf/util/util.h      |  60 ++++++++++++++++++
>  2 files changed, 163 insertions(+), 44 deletions(-)
> 
> -- 
> 1.8.3.4