kernel/tools/perf/util/smt.h, branch linux-6.2.y

perf topology: Add core_wide

2022-10-04T11:55:22Z

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 Cc: Ahmad Yasin Cc: Alexander Shishkin Cc: Andi Kleen Cc: Caleb Biggers Cc: Florian Fischer Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Kshipra Bopardikar Cc: Mark Rutland Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Perry Taylor Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Richter Cc: Xing Zhengjun Link: https://lore.kernel.org/r/20220831174926.579643-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf smt: Compute SMT from topology

2022-10-04T11:55:22Z

The topology records sibling threads. Rather than computing SMT using siblings in sysfs, reuse the values in topology. This only applies when the file smt/active isn't available. Signed-off-by: Ian Rogers Cc: Ahmad Yasin Cc: Alexander Shishkin Cc: Andi Kleen Cc: Caleb Biggers Cc: Florian Fischer Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Kshipra Bopardikar Cc: Mark Rutland Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Perry Taylor Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Richter Cc: Xing Zhengjun Link: https://lore.kernel.org/r/20220831174926.579643-4-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf smt: Tidy header guard add SPDX

2022-10-04T11:55:20Z

Make the header guard consistent with others. Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: Caleb Biggers Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Kshipra Bopardikar Cc: Mark Rutland Cc: Miaoqian Lin Cc: Namhyung Kim Cc: Perry Taylor Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Richter Cc: Xing Zhengjun Cc: florian fischer Link: http://lore.kernel.org/lkml/20220830164846.401143-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add utility function to detect SMT status

2017-08-22T15:09:04Z

Add an smt_on() function to return if SMT is enabled or disabled. Used in the next patch. Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20170811232634.30465-7-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo