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

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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: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Peter 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: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Adrian Hunter 2013-11-01 15:51:34 +02:00 committed by Arnaldo Carvalho de Melo
parent 35e17b2450
commit 539e6bb71e
5 changed files with 14 additions and 3 deletions
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6
tools/perf/Documentation/perf-record.txt
View File

@ -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]

2
tools/perf/builtin-record.c
View File

@ -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()
};

4
tools/perf/util/evlist.c
View File

@ -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();

4
tools/perf/util/evsel.c
View File

@ -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) {

1
tools/perf/util/target.h
View File

@ -12,6 +12,7 @@ struct target {
uid_t uid;
bool system_wide;
bool uses_mmap;
bool force_per_cpu;
};
enum target_errno {