linux-kernel - Re: [PATCH RFC 01/11] perf script: Move filter

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Date:   Tue, 22 Jun 2021 15:16:35 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     Jiri Olsa <jolsa@...hat.com>, Andi Kleen <ak@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Namhyung Kim <namhyung@...nel.org>,
        Leo Yan <leo.yan@...aro.org>,
        Kan Liang <kan.liang@...ux.intel.com>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH RFC 01/11] perf script: Move filter_cpu() earlier

Em Mon, Jun 21, 2021 at 06:05:04PM +0300, Adrian Hunter escreveu:
> Generally, it should be more efficient if filter_cpu() comes before
> machine__resolve() because filter_cpu() is much less code than
> machine__resolve().

Simple patch, I like it, applied.

- Arnaldo
 
> Example:
> 
>  $ perf record --sample-cpu -- make -C tools/perf >/dev/null
> 
> Before:
> 
>  $ perf stat -- perf script -C 0 >/dev/null
> 
>   Performance counter stats for 'perf script -C 0':
> 
>             116.94 msec task-clock                #    0.992 CPUs utilized
>                  2      context-switches          #   17.103 /sec
>                  0      cpu-migrations            #    0.000 /sec
>              8,187      page-faults               #   70.011 K/sec
>        478,351,812      cycles                    #    4.091 GHz
>        564,785,464      instructions              #    1.18  insn per cycle
>        114,341,105      branches                  #  977.789 M/sec
>          2,615,495      branch-misses             #    2.29% of all branches
> 
>        0.117840576 seconds time elapsed
> 
>        0.085040000 seconds user
>        0.032396000 seconds sys
> 
> After:
> 
>  $ perf stat -- perf script -C 0 >/dev/null
> 
>   Performance counter stats for 'perf script -C 0':
> 
>             107.45 msec task-clock                #    0.992 CPUs utilized
>                  3      context-switches          #   27.919 /sec
>                  0      cpu-migrations            #    0.000 /sec
>              7,964      page-faults               #   74.117 K/sec
>        438,417,260      cycles                    #    4.080 GHz
>        522,571,855      instructions              #    1.19  insn per cycle
>        105,187,488      branches                  #  978.921 M/sec
>          2,356,261      branch-misses             #    2.24% of all branches
> 
>        0.108282546 seconds time elapsed
> 
>        0.095935000 seconds user
>        0.011991000 seconds sys
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
> ---
>  tools/perf/builtin-script.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 57488d60b64a..08a2b5d51018 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -2191,6 +2191,9 @@ static int process_sample_event(struct perf_tool *tool,
>  		return 0;
>  	}
>  
> +	if (filter_cpu(sample))
> +		return 0;
> +
>  	if (machine__resolve(machine, &al, sample) < 0) {
>  		pr_err("problem processing %d event, skipping it.\n",
>  		       event->header.type);
> @@ -2200,9 +2203,6 @@ static int process_sample_event(struct perf_tool *tool,
>  	if (al.filtered)
>  		goto out_put;
>  
> -	if (filter_cpu(sample))
> -		goto out_put;
> -
>  	if (scripting_ops) {
>  		struct addr_location *addr_al_ptr = NULL;
>  		struct addr_location addr_al;
> -- 
> 2.17.1
> 

-- 

- Arnaldo