From 14cbfbeb76540cc0c53fbb0ba34b3a4900ebe40f Mon Sep 17 00:00:00 2001
From: Namhyung Kim <namhyung@kernel.org>
Date: Thu, 7 Jan 2016 20:41:53 +0900
Subject: 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>
---
 tools/perf/util/util.c | 27 +++++++++++++++++++++++++++
 tools/perf/util/util.h |  2 ++
 2 files changed, 29 insertions(+)

(limited to 'tools/perf/util')

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index aff0cfd83662..88b8f8d21f58 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -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;
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 4b519c59bdc3..fe915e616f9b 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -342,4 +342,6 @@ int fetch_kernel_version(unsigned int *puint,
 #define KVER_FMT	"%d.%d.%d"
 #define KVER_PARAM(x)	KVER_VERSION(x), KVER_PATCHLEVEL(x), KVER_SUBLEVEL(x)
 
+const char *perf_tip(const char *dirpath);
+
 #endif /* GIT_COMPAT_UTIL_H */
-- 
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