Re: [PATCH] perf parse-events: Set exclude_guest for user-space counting

Arnaldo Carvalho de Melo
2020-08-12T12:15:10Z

Em Wed, Aug 12, 2020 at 02:59:53PM +0800, Jin Yao escreveu:
> Currently if we run 'perf record -e cycles:u', exclude_guest is 0.
>
> But it doesn't make sense that we request for user-space counting
> but we also get the guest report.
>
> To keep perf semantics consistent and clear, this patch sets
> exclude_guest for user-space counting.

Applied, and also added this, that you should consider doing in the
future (modulo the "Committer testing:" header :) ):

Committer testing:

Before:

# perf record -e cycles:u
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.231 MB perf.data (91 samples) ]
#
# perf evlist -v
cycles:u: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, freq: 1, sample_id_all: 1
<SNIP>
#

After:

# perf record -e cycles:u
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.263 MB perf.data (403 samples) ]
#
# perf evlist -v
cycles:u: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|ID|CPU|PERIOD, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, freq: 1, sample_id_all: 1, exclude_guest: 1
#

----

I.e. show actual command output before and after that demonstrates the
problem and then the solution.

> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> ---
> tools/perf/util/parse-events.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index 9f7260e69113..4d809f1fe269 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -1794,6 +1794,8 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
> if (*str == 'u') {
> if (!exclude)
> exclude = eu = ek = eh = 1;
> + if (!exclude_GH)
> + eG = 1;
> eu = 0;
> } else if (*str == 'k') {
> if (!exclude)
> --
> 2.17.1
>

--

- Arnaldo