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| author |   Ian Rogers <irogers@google.com> | 2022-08-31 10:49:23 -0700 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-10-04 08:55:22 -0300 |
| commit | cc2c4e26ece19b4118f059f3a526c048793e58af (patch) | |
| tree | 1f440fc470e48cd5233d1f78ad9a7ef3c25caadf /tools/perf/util/smt.h | |
| parent | perf smt: Compute SMT from topology (diff) | |
| download | linux-dev-cc2c4e26ece19b4118f059f3a526c048793e58af.tar.xz linux-dev-cc2c4e26ece19b4118f059f3a526c048793e58af.zip | |
perf topology: Add core_wide
It is possible to optimize metrics when all SMT threads (CPUs) on a
core are measuring events in system wide mode. For example, TMA
metrics defines CORE_CLKS for Sandybrdige as:
if SMT is disabled:
CPU_CLK_UNHALTED.THREAD
if SMT is enabled and recording on all SMT threads:
CPU_CLK_UNHALTED.THREAD_ANY / 2
if SMT is enabled and not recording on all SMT threads:
(CPU_CLK_UNHALTED.THREAD/2)*
(1+CPU_CLK_UNHALTED.ONE_THREAD_ACTIVE/CPU_CLK_UNHALTED.REF_XCLK )
That is two more events are necessary when not gathering counts on all
SMT threads. To distinguish all SMT threads on a core vs system wide
(all CPUs) call the new property core wide. Add a core wide test that
determines the property from user requested CPUs, the topology and
system wide. System wide is required as other processes running on a
SMT thread will change the counts.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Ahmad Yasin <ahmad.yasin@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kshipra Bopardikar <kshipra.bopardikar@intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Miaoqian Lin <linmq006@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220831174926.579643-5-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/smt.h')
| -rw-r--r-- | tools/perf/util/smt.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/tools/perf/util/smt.h b/tools/perf/util/smt.h index e26999c6b8d4..ae9095f2c38c 100644 --- a/tools/perf/util/smt.h +++ b/tools/perf/util/smt.h @@ -7,4 +7,11 @@ struct cpu_topology; /* Returns true if SMT (aka hyperthreading) is enabled. */ bool smt_on(const struct cpu_topology *topology); +/* + * Returns true when system wide and all SMT threads for a core are in the + * user_requested_cpus map. + */ +bool core_wide(bool system_wide, const char *user_requested_cpu_list, + const struct cpu_topology *topology); + #endif /* __SMT_H */ |