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>
This commit is contained in:
Namhyung Kim 2016-01-07 20:41:53 +09:00 committed by Arnaldo Carvalho de Melo
parent fc284be9d8
commit 14cbfbeb76
8 changed files with 58 additions and 1 deletions

View file

@ -16,6 +16,8 @@
#include <linux/kernel.h>
#include <unistd.h>
#include "callchain.h"
#include "strlist.h"
#include <subcmd/exec-cmd.h>
struct callchain_param callchain_param = {
.mode = CHAIN_GRAPH_ABS,
@ -663,3 +665,28 @@ fetch_kernel_version(unsigned int *puint, char *str,
*puint = (version << 16) + (patchlevel << 8) + sublevel;
return 0;
}
const char *perf_tip(const char *dirpath)
{
struct strlist *tips;
struct str_node *node;
char *tip = NULL;
struct strlist_config conf = {
.dirname = system_path(dirpath) ,
};
tips = strlist__new("tips.txt", &conf);
if (tips == NULL || strlist__nr_entries(tips) == 1) {
tip = (char *)"Cannot find tips.txt file";
goto out;
}
node = strlist__entry(tips, random() % strlist__nr_entries(tips));
if (asprintf(&tip, "Tip: %s", node->s) < 0)
tip = (char *)"Tip: get more memory! ;-)";
out:
strlist__delete(tips);
return tip;
}