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>

1 files changed, 14 insertions, 0 deletions

diff --git a/tools/perf/Documentation/tips.txt b/tools/perf/Documentation/tips.txt
new file mode 100644
index 0000000..a1c10e3
--- /dev/null
+++ b/tools/perf/Documentation/tips.txt
@@ -0,0 +1,14 @@
+For a higher level overview, try: perf report --sort comm,dso
+Sample related events with: perf record -e '{cycles,instructions}:S'
+Compare performance results with: perf diff [<old file> <new file>]
+Boolean options have negative forms, e.g.: perf report --no-children
+Customize output of perf script with: perf script -F event,ip,sym
+Generate a script for your data: perf script -g <lang>
+Save output of perf stat using: perf stat record <target workload>
+Create an archive with symtabs to analyse on other machine: perf archive
+Search options using a keyword: perf report -h <keyword>
+Use parent filter to see specific call path: perf report -p <regex>
+List events using substring match: perf list <keyword>
+To see list of saved events and attributes: perf evlist -v
+Use --symfs <dir> if your symbol files are in non-standard locations
+To see callchains in a more compact form: perf report -g folded