perf report: Show random usage tip on the help line
Currently perf report only shows a help message "For a higher level
overview, try: perf report --sort comm,dso" unconditionally (even if
the sort keys were used). Add more help tips and show randomly.
Load tips from ${prefix}/share/doc/perf-tip/tips.txt file.
$ perf report | tail
0.10% swapper [kernel.vmlinux] [k] irq_exit
0.09% swapper [kernel.vmlinux] [k] flush_smp_call_function_queue
0.08% swapper [kernel.vmlinux] [k] native_write_msr_safe
0.03% swapper [kernel.vmlinux] [k] group_sched_in
0.01% perf [kernel.vmlinux] [k] native_write_msr_safe
#
# (Tip: Search options using a keyword: perf report -h <keyword>)
#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1452166913-27046-1-git-send-email-namhyung@kernel.org
[ Renamed it to perf_tip() and the parameter dirname to dirpath to fix the build on older distros ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index cb1d249..a929618 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -19,6 +19,8 @@
#include "util/debug.h"
#include <api/fs/tracing_path.h>
#include <pthread.h>
+#include <stdlib.h>
+#include <time.h>
const char perf_usage_string[] =
"perf [--version] [--help] [OPTIONS] COMMAND [ARGS]";
@@ -542,6 +544,8 @@
if (!cmd)
cmd = "perf-help";
+ srandom(time(NULL));
+
/* get debugfs/tracefs mount point from /proc/mounts */
tracing_path_mount();