Commit 539e6bb7 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo
Browse files

perf record: Add an option to force per-cpu mmaps 



By default, when tasks are specified (i.e. -p, -t or -u options)
per-thread mmaps are created.

Add an option to override that and force per-cpu mmaps.

Further comments by peterz:

So this option allows -t/-p/-u to create one buffer per cpu and attach
all the various thread/process/user tasks' their counters to that one
buffer?

As opposed to the current state where each such counter would have its
own buffer.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Tested-by: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1383313899-15987-7-git-send-email-adrian.hunter@intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 35e17b24

tools/perf/Documentation/perf-record.txt

+6 −0
Original line number Diff line number Diff line
@@ -201,6 +201,12 @@ abort events and some memory events in precise mode on modern Intel CPUs. 
--transaction::

Record transaction flags for transaction related events.



--force-per-cpu::

Force the use of per-cpu mmaps.  By default, when tasks are specified (i.e. -p,

-t or -u options) per-thread mmaps are created.  This option overrides that and

forces per-cpu mmaps.  A side-effect of that is that inheritance is

automatically enabled.  Add the -i option also to disable inheritance.



SEE ALSO

--------

linkperf:perf-stat[1], linkperf:perf-list[1]

tools/perf/builtin-record.c

+2 −0
Original line number Diff line number Diff line
@@ -888,6 +888,8 @@ const struct option record_options[] = { 
		    "sample by weight (on special events only)"),

	OPT_BOOLEAN(0, "transaction", &record.opts.sample_transaction,

		    "sample transaction flags (special events only)"),

	OPT_BOOLEAN(0, "force-per-cpu", &record.opts.target.force_per_cpu,

		    "force the use of per-cpu mmaps"),

	OPT_END()

};

tools/perf/util/evlist.c

+3 −1
Original line number Diff line number Diff line
@@ -819,7 +819,9 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target) 
	if (evlist->threads == NULL)

		return -1;



	if (target__has_task(target))

	if (target->force_per_cpu)

		evlist->cpus = cpu_map__new(target->cpu_list);

	else if (target__has_task(target))

		evlist->cpus = cpu_map__dummy_new();

	else if (!target__has_cpu(target) && !target->uses_mmap)

		evlist->cpus = cpu_map__dummy_new();

tools/perf/util/evsel.c

+2 −2
Original line number Diff line number Diff line
@@ -645,7 +645,7 @@ void perf_evsel__config(struct perf_evsel *evsel, 
		}

	}



	if (target__has_cpu(&opts->target))

	if (target__has_cpu(&opts->target) || opts->target.force_per_cpu)

		perf_evsel__set_sample_bit(evsel, CPU);



	if (opts->period)
@@ -653,7 +653,7 @@ void perf_evsel__config(struct perf_evsel *evsel, 


	if (!perf_missing_features.sample_id_all &&

	    (opts->sample_time || !opts->no_inherit ||

	     target__has_cpu(&opts->target)))

	     target__has_cpu(&opts->target) || opts->target.force_per_cpu))

		perf_evsel__set_sample_bit(evsel, TIME);



	if (opts->raw_samples) {

tools/perf/util/target.h

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ struct target { 
	uid_t	     uid;

	bool	     system_wide;

	bool	     uses_mmap;

	bool	     force_per_cpu;

};



enum target_errno {

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