Commit daca23b2 authored by Jin Yao's avatar Jin Yao Committed by Arnaldo Carvalho de Melo
Browse files

perf diff: Support --cpu filter option 



To improve 'perf diff', implement a --cpu filter option.

Multiple CPUs can be provided as a comma-separated list with no space:
0,1.  Ranges of CPUs are specified with -: 0-2. Default is to report
samples on all CPUs.

For example,

  perf diff --cpu 0,1

It only diff the samples for CPU0 and CPU1.

Signed-off-by: default avatarJin Yao <yao.jin@linux.intel.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1551791143-10334-3-git-send-email-yao.jin@linux.intel.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 4802138d

tools/perf/Documentation/perf-diff.txt

+5 −0
Original line number Diff line number Diff line
@@ -163,6 +163,11 @@ OPTIONS 
	the end of perf.data.old and analyzes the perf.data from the

	timestamp 3971.150589 to the end of perf.data.



--cpu:: Only diff samples for the list of CPUs provided. Multiple CPUs can

	be provided as a comma-separated list with no space: 0,1. Ranges of

	CPUs are specified with -: 0-2. Default is to report samples on all

	CPUs.



COMPARISON

----------

The comparison is governed by the baseline file. The baseline perf.data

tools/perf/builtin-diff.c

+16 −0
Original line number Diff line number Diff line
@@ -83,6 +83,9 @@ static unsigned int sort_compute = 1; 
static s64 compute_wdiff_w1;

static s64 compute_wdiff_w2;



static const char		*cpu_list;

static DECLARE_BITMAP(cpu_bitmap, MAX_NR_CPUS);



enum {

	COMPUTE_DELTA,

	COMPUTE_RATIO,
@@ -354,6 +357,11 @@ static int diff__process_sample_event(struct perf_tool *tool, 
		return -1;

	}



	if (cpu_list && !test_bit(sample->cpu, cpu_bitmap)) {

		ret = 0;

		goto out_put;

	}



	if (!hists__add_entry(hists, &al, NULL, NULL, NULL, sample, true)) {

		pr_warning("problem incrementing symbol period, skipping event\n");

		goto out_put;
@@ -892,6 +900,13 @@ static int __cmd_diff(void) 
				goto out_delete;

		}



		if (cpu_list) {

			ret = perf_session__cpu_bitmap(d->session, cpu_list,

						       cpu_bitmap);

			if (ret < 0)

				goto out_delete;

		}



		ret = perf_session__process_events(d->session);

		if (ret) {

			pr_err("Failed to process %s\n", d->data.path);
@@ -969,6 +984,7 @@ static const struct option options[] = { 
		     "How to display percentage of filtered entries", parse_filter_percentage),

	OPT_STRING(0, "time", &pdiff.time_str, "str",

		   "Time span (time percent or absolute timestamp)"),

	OPT_STRING(0, "cpu", &cpu_list, "cpu", "list of cpus to profile"),

	OPT_END()

};

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