Re: [PATCH] perf sched map: Add command-name option to filter the output map
From: Madadi Vineeth Reddy
Date: Fri Jun 07 2024 - 01:49:58 EST
Hi Namhyung,
On 07/06/24 06:20, Namhyung Kim wrote:
> Hello,
>
> Sorry for the late reply.
>
> On Wed, Apr 17, 2024 at 08:55:21PM +0530, Madadi Vineeth Reddy wrote:
>> By default, perf sched map prints sched-in events for all the tasks
>> which may not be required all the time as it prints lot of symbols
>> and rows to the terminal.
>>
>> With --command-name option, one could specify the specific command
>> for which the map has to be shown. This would help in analyzing the
>> CPU usage patterns easier for that specific command. Since multiple
>> PID's might have the same command name, using command-name filter
>> would be more useful for debugging.
>>
>> For other tasks, instead of printing the symbol, ** is printed and
>> the same . is used to represent idle. ** is used instead of symbol
>> for other tasks because it helps in clear visualization of command
>> of interest and secondly the symbol itself doesn't mean anything
>> because the sched-in of that symbol will not be printed(first sched-in
>> contains pid and the corresponding symbol).
>>
>> 6.8.0
>> ======
>> *A0 213864.670142 secs A0 => migration/0:18
>> *. 213864.670148 secs . => swapper:0
>> . *B0 213864.670217 secs B0 => migration/1:21
>> . *. 213864.670223 secs
>> . . *C0 213864.670247 secs C0 => migration/2:26
>> . . *. 213864.670252 secs
>>
>> 6.8.0 + patch (--command-name = schbench)
>> =============
>> ** . ** *A0 213864.671055 secs A0 => schbench:104834
>> *B0 . . A0 213864.671156 secs B0 => schbench:104835
>> *C0 . . A0 213864.671187 secs C0 => schbench:104836
>> *D0 . . A0 213864.671219 secs D0 => schbench:104837
>> *E0 . . A0 213864.671250 secs E0 => schbench:104838
>> E0 . *D0 A0
>>
>> This helps in visualizing how a benchmark like schbench is spread over
>> the available cpus while also knowing which cpus are idle(.) and which
>> are not(**). This will be more useful as number of CPUs increase.
>
> Yeah I think this is good! Thanks for working on this.
>
> But I guess people want to see when the tasks were sched out as well.
> Can you please add that too?
>
In the current implementation, we will know when a task is scheduled out
implicitly.
For instance, from the above example,
** . ** *A0 213864.671055 secs A0 => schbench:104834
*B0 . . A0 213864.671156 secs B0 => schbench:104835
*C0 . . A0 213864.671187 secs C0 => schbench:104836
In CPU0 (first column), the sched-in of C0 in last line indicates that
B0 is scheduled out. Similarly down the line if A0 is scheduled out,
we will know it by some other task being scheduled-in.
I hope this is fine. Let me know if you have any ideas or suggestions.
>>
>> Signed-off-by: Madadi Vineeth Reddy <vineethr@xxxxxxxxxxxxx>
>> ---
>> tools/perf/Documentation/perf-sched.txt | 4 ++++
>> tools/perf/builtin-sched.c | 17 ++++++++++++++---
>> 2 files changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/tools/perf/Documentation/perf-sched.txt b/tools/perf/Documentation/perf-sched.txt
>> index 5fbe42bd599b..b04a37560935 100644
>> --- a/tools/perf/Documentation/perf-sched.txt
>> +++ b/tools/perf/Documentation/perf-sched.txt
>> @@ -94,6 +94,10 @@ OPTIONS for 'perf sched map'
>> --color-pids::
>> Highlight the given pids.
>>
>> +--command-name::
>> + Map output only for the given command name.
>> + (** indicates other tasks while . is idle).
>
> Probably we can support multiple names in CSV.
>
Yes, that's a good idea. I will implement it in v2. Thank you for taking a look.
Thanks and Regards
Madadi Vineeth Reddy
> Thanks,
> Namhyung
>
>
>> +
>> OPTIONS for 'perf sched timehist'
>> ---------------------------------
>> -k::
>> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
>> index 0fce7d8986c0..e60836da53e5 100644
>> --- a/tools/perf/builtin-sched.c
>> +++ b/tools/perf/builtin-sched.c
>> @@ -156,6 +156,7 @@ struct perf_sched_map {
>> const char *color_pids_str;
>> struct perf_cpu_map *color_cpus;
>> const char *color_cpus_str;
>> + const char *command;
>> struct perf_cpu_map *cpus;
>> const char *cpus_str;
>> };
>> @@ -1594,8 +1595,6 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>>
>> sched->curr_thread[this_cpu.cpu] = thread__get(sched_in);
>>
>> - printf(" ");
>> -
>> new_shortname = 0;
>> if (!tr->shortname[0]) {
>> if (!strcmp(thread__comm_str(sched_in), "swapper")) {
>> @@ -1605,7 +1604,8 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>> */
>> tr->shortname[0] = '.';
>> tr->shortname[1] = ' ';
>> - } else {
>> + } else if (!sched->map.command || !strcmp(thread__comm_str(sched_in),
>> + sched->map.command)) {
>> tr->shortname[0] = sched->next_shortname1;
>> tr->shortname[1] = sched->next_shortname2;
>>
>> @@ -1618,10 +1618,18 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>> else
>> sched->next_shortname2 = '0';
>> }
>> + } else {
>> + tr->shortname[0] = '*';
>> + tr->shortname[1] = '*';
>> }
>> new_shortname = 1;
>> }
>>
>> + if (sched->map.command && strcmp(thread__comm_str(sched_in), sched->map.command))
>> + goto skip;
>> +
>> + printf(" ");
>> +
>> for (i = 0; i < cpus_nr; i++) {
>> struct perf_cpu cpu = {
>> .cpu = sched->map.comp ? sched->map.comp_cpus[i].cpu : i,
>> @@ -1678,6 +1686,7 @@ static int map_switch_event(struct perf_sched *sched, struct evsel *evsel,
>> out:
>> color_fprintf(stdout, color, "\n");
>>
>> +skip:
>> thread__put(sched_in);
>>
>> return 0;
>> @@ -3560,6 +3569,8 @@ int cmd_sched(int argc, const char **argv)
>> "highlight given CPUs in map"),
>> OPT_STRING(0, "cpus", &sched.map.cpus_str, "cpus",
>> "display given CPUs in map"),
>> + OPT_STRING(0, "command-name", &sched.map.command, "command",
>> + "map output only for the given command name"),
>> OPT_PARENT(sched_options)
>> };
>> const struct option timehist_options[] = {
>> --
>> 2.39.1
>>