From 7f94af7a489fada17d28cc60e8f4409ce216bd6d Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Mon, 5 Oct 2015 20:06:05 +0200 Subject: perf tools: Introduce 'P' modifier to request max precision The 'P' will cause the event to get maximum possible detected precise level. Following record: $ perf record -e cycles:P ... will detect maximum precise level for 'cycles' event and use it. Commiter note: Testing it: $ perf record -e cycles:P usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data (9 samples) ] $ perf evlist cycles:P $ perf evlist -v cycles:P: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, precise_ip: 2, sample_id_all: 1, mmap2: 1, comm_exec: 1 $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Don Zickus Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1444068369-20978-6-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-list.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'tools/perf/Documentation') diff --git a/tools/perf/Documentation/perf-list.txt b/tools/perf/Documentation/perf-list.txt index ad60c6ea1997..79483f40e991 100644 --- a/tools/perf/Documentation/perf-list.txt +++ b/tools/perf/Documentation/perf-list.txt @@ -30,6 +30,7 @@ counted. The following modifiers exist: G - guest counting (in KVM guests) H - host counting (not in KVM guests) p - precise level + P - use maximum detected precise level S - read sample value (PERF_SAMPLE_READ) D - pin the event to the PMU -- cgit v1.2.3