6fe61cb4ae
Rename 'Switches' to 'Count' and document metrics shown for perf sched latency output. Also add options possible with perf sched latency. Initially, after seeing the output of 'perf sched latency', the term 'Switches' seemed like it's the number of context switches-in for a particular task, but upon going through the code, it was observed that it's actually keeping track of number of times a delay was calculated so that it is used in calculation of the average delay. Actually, the switches here is a subset of number of context switches-in because there are some cases where the count is not incremented in switch-in handler 'add_sched_in_event'. For example when a task is switched-in while it's state is not ready to run(!= THREAD_WAIT_CPU). commit d9340c1db3f52460 ("perf sched: Display time in milliseconds, reorganize output") changed it from the original count to switches. So, renamed switches to count to make things a bit more clearer and added the metrics description of latency in the document. Reviewed-by: Aditya Gupta <adityag@linux.ibm.com> Signed-off-by: Madadi Vineeth Reddy <vineethr@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.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> Link: https://lore.kernel.org/r/20240328090005.8321-1-vineethr@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>