Re: [PATCH RFC 01/11] perf script: Move filter_cpu() earlier

From: Arnaldo Carvalho de Melo
Date: Tue Jun 22 2021 - 14:16:41 EST


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@xxxxxxxxx>
> ---
> 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