Re: [PATCH 1/6] perf mem: Add --ldlat option

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Mar 24, 2016 at 01:52:15PM +0100, Jiri Olsa escreveu:
> Adding --ldlat option to specify desired latency
> for loads event.
> 
> Specify 50 as loads event latency:
> 
>   $ perf mem record -e ldlat-loads -v --ldlat 50 true
>   calling: record -W -d -e cpu/mem-loads,ldlat=50/P true

We have all this infrastructure to set per-event settings, on the
command line, and here we end up adding a separate command line option
to do that? Why not something like:

	perf mem record -e ldlat-loads/lat=50/ true

?

- Arnaldo
 
> Link: http://lkml.kernel.org/n/tip-ec2m0cvivkfs8uhtiv411hfc@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
>  tools/perf/Documentation/perf-mem.txt |  3 +++
>  tools/perf/builtin-mem.c              |  1 +
>  tools/perf/util/mem-events.c          | 17 ++++++++++++++++-
>  tools/perf/util/mem-events.h          |  1 +
>  4 files changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/Documentation/perf-mem.txt b/tools/perf/Documentation/perf-mem.txt
> index 43310d8661fe..6676d2784733 100644
> --- a/tools/perf/Documentation/perf-mem.txt
> +++ b/tools/perf/Documentation/perf-mem.txt
> @@ -48,6 +48,9 @@ OPTIONS
>  	option can be passed in record mode. It will be interpreted the same way as perf
>  	record.
>  
> +--ldload::
> +	Specify desired latency for loads event.
> +
>  SEE ALSO
>  --------
>  linkperf:perf-record[1], linkperf:perf-report[1]
> diff --git a/tools/perf/builtin-mem.c b/tools/perf/builtin-mem.c
> index 914f6fe192e3..bf0bfca5be20 100644
> --- a/tools/perf/builtin-mem.c
> +++ b/tools/perf/builtin-mem.c
> @@ -66,6 +66,7 @@ static int __cmd_record(int argc, const char **argv, struct perf_mem *mem)
>  	OPT_CALLBACK('e', "event", &mem, "event",
>  		     "event selector. use 'perf mem record -e list' to list available events",
>  		     parse_record_events),
> +	OPT_UINTEGER(0, "ldlat", &perf_mem_events__loads_ldlat, "mem-loads latency"),
>  	OPT_INCR('v', "verbose", &verbose,
>  		 "be more verbose (show counter open errors, etc)"),
>  	OPT_END()
> diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
> index e6b01e6f70a0..3ff60f08a778 100644
> --- a/tools/perf/util/mem-events.c
> +++ b/tools/perf/util/mem-events.c
> @@ -10,10 +10,12 @@
>  #include "debug.h"
>  #include "symbol.h"
>  
> +unsigned int perf_mem_events__loads_ldlat = 30;
> +
>  #define E(t, n, s) { .tag = t, .name = n, .sysfs_name = s }
>  
>  struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
> -	E("ldlat-loads",	"cpu/mem-loads,ldlat=30/P",	"mem-loads"),
> +	E("ldlat-loads",	"cpu/mem-loads,ldlat=%u/P",	"mem-loads"),
>  	E("ldlat-stores",	"cpu/mem-stores/P",		"mem-stores"),
>  	E("stlb-miss-loads",	"cpu/mem-stlb-miss-loads/P",	"mem-stlb-miss-loads"),
>  	E("stlb-miss-stores",	"cpu/mem-stlb-miss-stores/P",	"mem-stlb-miss-stores"),
> @@ -39,8 +41,21 @@ struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX] = {
>  
>  #undef E
>  
> +static char mem_loads_name[100];
> +static bool mem_loads_name__init;
> +
>  char *perf_mem_events__name(int i)
>  {
> +	if (i == PERF_MEM_EVENTS__LOAD) {
> +		if (!mem_loads_name__init) {
> +			mem_loads_name__init = true;
> +			scnprintf(mem_loads_name, sizeof(mem_loads_name),
> +				  perf_mem_events[i].name,
> +				  perf_mem_events__loads_ldlat);
> +		}
> +		return mem_loads_name;
> +	}
> +
>  	return (char *)perf_mem_events[i].name;
>  }
>  
> diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
> index de88f4267cd1..939786ffab2a 100644
> --- a/tools/perf/util/mem-events.h
> +++ b/tools/perf/util/mem-events.h
> @@ -37,6 +37,7 @@ enum {
>  };
>  
>  extern struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX];
> +extern unsigned int perf_mem_events__loads_ldlat;
>  
>  int perf_mem_events__parse(const char *str);
>  int perf_mem_events__init(void);
> -- 
> 2.4.3