Re: [PATCH] perf top: Use evsel's cpus to replace user_requested_cpus

Liang, Kan
2023-12-18T21:07:41Z

On 2023-12-18 3:23 p.m., Arnaldo Carvalho de Melo wrote:
> Em Fri, Dec 15, 2023 at 01:53:12PM -0500, Liang, Kan escreveu:
>> On 2023-12-15 1:26 p.m., Arnaldo Carvalho de Melo wrote:
>>> Right, I implemented it in a slightly different way, but end result
>>> should be the same:
>
>>> From: Arnaldo Carvalho de Melo <acme@redhat.com>
>>> Date: Fri, 15 Dec 2023 15:23:30 -0300
>>> Subject: [PATCH 1/1] perf evlist: Move event attributes to after the / when uniquefying using the PMU name
>
>> Looks good to me and verified.
>
>> Tested-by: Kan Liang <kan.liang@linux.intel.com>
>
> I ended up with a bit more simplified version:
>
> From 22ecc4601e28a12661f14ca877e39348dab6be8e Mon Sep 17 00:00:00 2001
> From: Arnaldo Carvalho de Melo <acme@redhat.com>
> Date: Fri, 15 Dec 2023 15:23:30 -0300
> Subject: [PATCH 1/1] perf evlist: Move event attributes to after the / when
> uniquefying using the PMU name
>
> When turning an event with attributes to the format including the PMU we
> need to move the "event:attributes" format to "event/attributes/" so
> that we can copy the event displayed and use it in the command line,
> i.e. in 'perf top' we had:
>
> 1K cpu_atom/cycles:P/
> 11K cpu_core/cycles:P/
>
> If I try to use that on the command line:
>
> # perf top -e cpu_atom/cycles:P/
> event syntax error: 'cpu_atom/cycles:P/'
> \___ Bad event or PMU
>
> Unable to find PMU or event on a PMU of 'cpu_atom'
>
> Initial error:
> event syntax error: 'cpu_atom/cycles:P/'
> \___ unknown term 'cycles:P' for pmu
> 'cpu_atom'
>
> valid terms:
>
> event,pc,edge,offcore_rsp,ldlat,inv,umask,cmask,config,config1,config2,config3,name,period,freq,branch_type,time,call-graph,stack-size,no-inherit,inherit,max-stack,nr,no-overwrite,overwrite ,driver-config,percore,aux-output,aux-sample-size,metric-id,raw,legacy-cache,hardware
> Run
> 'perf list' for a list of valid events
>
> Usage: perf top [<options>]
>
> -e, --event <event> event selector. use 'perf list' to list available events
> #
>
> Cc: Hector Martin <marcan@marcan.st>
> Cc: Ian Rogers <irogers@google.com>
> Cc: Kan Liang <kan.liang@linux.intel.com>
> Cc: Marc Zyngier <maz@kernel.org>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> Link: https://lore.kernel.org/lkml/ZXxyanyZgWBTOnoK@kernel.org
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Tested-by: Kan Liang <kan.liang@linux.intel.com>

Thanks,
Kan
> ---
> tools/perf/util/evlist.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
> index 6f0892803c2249af..95f25e9fb994ab2a 100644
> --- a/tools/perf/util/evlist.c
> +++ b/tools/perf/util/evlist.c
> @@ -2521,9 +2521,8 @@ void evlist__warn_user_requested_cpus(struct evlist *evlist, const char *cpu_lis
>
> void evlist__uniquify_name(struct evlist *evlist)
> {
> + char *new_name, empty_attributes[2] = ":", *attributes;
> struct evsel *pos;
> - char *new_name;
> - int ret;
>
> if (perf_pmus__num_core_pmus() == 1)
> return;
> @@ -2535,11 +2534,17 @@ void evlist__uniquify_name(struct evlist *evlist)
> if (strchr(pos->name, '/'))
> continue;
>
> - ret = asprintf(&new_name, "%s/%s/",
> - pos->pmu_name, pos->name);
> - if (ret) {
> + attributes = strchr(pos->name, ':');
> + if (attributes)
> + *attributes = '\0';
> + else
> + attributes = empty_attributes;
> +
> + if (asprintf(&new_name, "%s/%s/%s", pos->pmu_name, pos->name, attributes + 1)) {
> free(pos->name);
> pos->name = new_name;
> + } else {
> + *attributes = ':';
> }
> }
> }