From 7831bf236505bcb2a0a1255e7f3e902a0cb732d6 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Thu, 1 Mar 2018 14:25:56 -0300 Subject: [PATCH] perf top: Allow asking for the maximum allowed sample rate Add the handy '-F max' shortcut, just introduced to 'perf record', to reading and using the kernel.perf_event_max_sample_rate value as the user supplied sampling frequency: Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-hz04f296zccknnb5at06a6q0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-top.txt | 4 +++- tools/perf/builtin-top.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt index 8a32cc77bead..a039407d63b8 100644 --- a/tools/perf/Documentation/perf-top.txt +++ b/tools/perf/Documentation/perf-top.txt @@ -55,7 +55,9 @@ Default is to monitor all CPUS. -F :: --freq=:: - Profile at this frequency. + Profile at this frequency. Use 'max' to use the currently maximum + allowed frequency, i.e. the value in the kernel.perf_event_max_sample_rate + sysctl. -i:: --inherit:: diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index 35ac016fcb98..bb4f9fafd11d 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1307,7 +1307,9 @@ int cmd_top(int argc, const char **argv) OPT_STRING(0, "sym-annotate", &top.sym_filter, "symbol name", "symbol to annotate"), OPT_BOOLEAN('z', "zero", &top.zero, "zero history across updates"), - OPT_UINTEGER('F', "freq", &opts->user_freq, "profile at this frequency"), + OPT_CALLBACK('F', "freq", &top.record_opts, "freq or 'max'", + "profile at this frequency", + record__parse_freq), OPT_INTEGER('E', "entries", &top.print_entries, "display this many functions"), OPT_BOOLEAN('U', "hide_user_symbols", &top.hide_user_symbols, -- 2.30.2