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authorK Prateek Nayak <kprateek.nayak@amd.com>2023-05-17 20:27:44 +0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2023-05-23 22:10:13 +0300
commitaab667ca8837e45fda0204bed7b59abd634c0b2b (patch)
treebb014c00c3dd53469d10845df946cb9e1aae5442 /tools/perf/Documentation
parent4b87406a3b590888edf02705a815eb62e122e9ba (diff)
downloadlinux-aab667ca8837e45fda0204bed7b59abd634c0b2b.tar.xz
perf stat: Add "--per-cache" aggregation option and document it
This patch adds support for "--per-cache" option for aggregation at a particular cache level and documents the same. Following is the output of 'perf stat' with aggregation at L3 for the event "ls_dmnd_fills_from_sys.ext_cache_remote" on a dual socket 3rd Generation EPYC Processor (2 x 64C/128T - 16 LLCs) when running hackbench pinned to 4 LLCs: $ sudo perf stat --per-cache=L3 -a -e ls_dmnd_fills_from_sys.ext_cache_remote -- \ taskset -c 0-15,64-79,128-143,192-207 \ perf bench sched messaging -p -t -l 100000 -g 8 ... Performance counter stats for 'system wide': S0-D0-L3-ID0 16 9,500,803 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID8 16 6,338,099 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID16 16 355,005 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID24 16 22,067 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID32 16 16,321 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID40 16 11,619 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID48 16 4,238 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID56 16 31,158 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID64 16 28,242,452 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID72 16 22,906,973 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID80 16 72,898 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID88 16 56,907 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID96 16 20,456 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID104 16 40,913 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID112 16 78,113 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID120 16 37,897 ls_dmnd_fills_from_sys.ext_cache_remote Also support 'perf stat record' and 'perf stat report' with the ability to specify a different cache level to aggregate data at when running 'perf stat report'. $ sudo perf stat record --per-cache=L2 -a -e ls_dmnd_fills_from_sys.ext_cache_remote -- \ taskset -c 0-15,64-79,128-143,192-207 \ perf bench sched messaging -p -t -l 100000 -g 8 ... Performance counter stats for 'system wide': S0-D0-L2-ID0 2 1,442,061 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID1 2 1,548,994 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID2 2 1,553,557 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID3 2 1,420,122 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID4 2 1,465,461 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID5 2 1,455,153 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID6 2 1,595,237 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID7 2 1,499,321 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L2-ID8 2 1,919,025 ls_dmnd_fills_from_sys.ext_cache_remote ... S1-D1-L2-ID127 2 21,295 ls_dmnd_fills_from_sys.ext_cache_remote $ sudo perf stat report --per-cache=L3 Performance counter stats for 'perf stat record --per-cache=L2 -a -e ls_dmnd_fills_from_sys.ext_cache_remote --\ taskset -c 0-15,64-79,128-143,192-207 \ perf bench sched messaging -p -t -l 100000 -g 8': S0-D0-L3-ID0 16 11,979,906 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID8 16 14,257,202 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID16 16 377,484 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID24 16 27,224 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID32 16 26,816 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID40 16 14,461 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID48 16 10,499 ls_dmnd_fills_from_sys.ext_cache_remote S0-D0-L3-ID56 16 53,817 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID64 16 27,361,987 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID72 16 37,299,024 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID80 16 84,125 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID88 16 64,561 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID96 16 13,403 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID104 16 20,138 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID112 16 93,220 ls_dmnd_fills_from_sys.ext_cache_remote S1-D1-L3-ID120 16 35,465 ls_dmnd_fills_from_sys.ext_cache_remote On the above system, the domain covered by S0-D0-L3-ID0 contains S0-D0-L2-ID0 to S0-D0-L2-ID7, the corresponding count for L3-ID0 is equal to the sum of counts for L2-ID0 to L2-ID7. Add documentation for the newly introduced "--per-cache" option. Suggested-by: Gautham Shenoy <gautham.shenoy@amd.com> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ananth Narayan <ananth.narayan@amd.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Wen Pu <puwen@hygon.cn> Link: https://lore.kernel.org/r/20230517172745.5833-5-kprateek.nayak@amd.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-stat.txt16
1 files changed, 16 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 29bdcfa93f04..785f0e2bcfac 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -308,6 +308,14 @@ use --per-die in addition to -a. (system-wide). The output includes the
die number and the number of online processors on that die. This is
useful to gauge the amount of aggregation.
+--per-cache::
+Aggregate counts per cache instance for system-wide mode measurements. By
+default, the aggregation happens for the cache level at the highest index
+in the system. To specify a particular level, mention the cache level
+alongside the option in the format [Ll][1-9][0-9]*. For example:
+Using option "--per-cache=l3" or "--per-cache=L3" will aggregate the
+information at the boundary of the level 3 cache in the system.
+
--per-core::
Aggregate counts per physical processor for system-wide mode measurements. This
is a useful mode to detect imbalance between physical cores. To enable this mode,
@@ -379,6 +387,14 @@ Aggregate counts per processor socket for system-wide mode measurements.
--per-die::
Aggregate counts per processor die for system-wide mode measurements.
+--per-cache::
+Aggregate counts per cache instance for system-wide mode measurements. By
+default, the aggregation happens for the cache level at the highest index
+in the system. To specify a particular level, mention the cache level
+alongside the option in the format [Ll][1-9][0-9]*. For example: Using
+option "--per-cache=l3" or "--per-cache=L3" will aggregate the
+information at the boundary of the level 3 cache in the system.
+
--per-core::
Aggregate counts per physical processor for system-wide mode measurements.