linux-kernel - Re: [PATCH 2/2] perf script: Don't disable use

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Message-ID: <57B1988B.3020806@huawei.com>
Date:	Mon, 15 Aug 2016 18:25:15 +0800
From:	Hekuang <hekuang@...wei.com>
To:	<acme@...nel.org>, <peterz@...radead.org>, <mingo@...hat.com>,
	<alexander.shishkin@...ux.intel.com>
CC:	<wangnan0@...wei.com>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] perf script: Don't disable use_callchain if input is
 pipe

ping.

在 2016/8/4 19:25, He Kuang 写道:
> Because perf data from pipe do not have a header with evsel attr, we
> should not check that and disable symbol_conf.use_callchain. Otherwise,
> perf script won't show callchains even if the data stream contains
> callchain.
>
> Before:
>    $ perf record -g -o - uname |perf script
>    Linux
>    [ perf record: Woken up 1 times to write data ]
>    [ perf record: Captured and wrote 0.000 MB - ]
>    uname  1828 182630.186578:  250000 cpu-clock:  ..b9499 setup_arg_pages
>    uname  1828 182630.186850:  250000 cpu-clock:  ..83b20 ___might_sleep
>    uname  1828 182630.187153:  250000 cpu-clock:  ..4b6be file_map_prot_ch
>    ...
>
> After:
>    $ perf record -g -o - uname |perf script
>    Linux
>    [ perf record: Woken up 1 times to write data ]
>    [ perf record: Captured and wrote 0.000 MB - ]
>    uname  1833 182675.927099:     250000 cpu-clock:
>                    ba5520 _raw_spin_lock+0xfe200040 ([kernel.kallsyms])
>                    389dd4 expand_downwards+0xfe200154 ([kernel.kallsyms])
>                    389f34 expand_stack+0xfe200024 ([kernel.kallsyms])
>                    3b957e setup_arg_pages+0xfe20019e ([kernel.kallsyms])
>                    40c80f load_elf_binary+0xfe20042f ([kernel.kallsyms])
>                    ...
>
> Signed-off-by: He Kuang <hekuang@...wei.com>
> ---
>   tools/perf/builtin-script.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index d47aef9..ec8df8f 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -371,14 +371,16 @@ static int perf_session__check_output_opt(struct perf_session *session)
>   
>   	if (!no_callchain) {
>   		bool use_callchain = false;
> +		bool not_pipe = false;
>   
>   		evlist__for_each_entry(session->evlist, evsel) {
> +			not_pipe = true;
>   			if (evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
>   				use_callchain = true;
>   				break;
>   			}
>   		}
> -		if (!use_callchain)
> +		if (not_pipe && !use_callchain)
>   			symbol_conf.use_callchain = false;
>   	}
>