[RFC/PATCH v3] perf report: Show random usage tip on the help line

From: Namhyung Kim
Date: Thu Jan 07 2016 - 06:42:55 EST


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@xxxxxxxxxx>
---
More tips will be added later once this basic structure is done.

tools/perf/Build | 1 +
tools/perf/Documentation/tips.txt | 14 ++++++++++++++
tools/perf/Makefile.perf | 3 +++
tools/perf/builtin-report.c | 2 +-
tools/perf/config/Makefile | 6 ++++++
tools/perf/perf.c | 4 ++++
tools/perf/util/util.c | 27 +++++++++++++++++++++++++++
tools/perf/util/util.h | 2 ++
8 files changed, 58 insertions(+), 1 deletion(-)
create mode 100644 tools/perf/Documentation/tips.txt

diff --git a/tools/perf/Build b/tools/perf/Build
index 00c4b8c3d8ca..6b67e6f4179f 100644
--- a/tools/perf/Build
+++ b/tools/perf/Build
@@ -41,6 +41,7 @@ CFLAGS_perf.o += -DPERF_HTML_PATH="BUILD_STR($(htmldir_SQ))" \
-DPREFIX="BUILD_STR($(prefix_SQ))" \
-include $(OUTPUT)PERF-VERSION-FILE
CFLAGS_builtin-trace.o += -DSTRACE_GROUPS_DIR="BUILD_STR($(STRACE_GROUPS_DIR_SQ))"
+CFLAGS_builtin-report.o += -DTIPDIR="BUILD_STR($(tipdir_SQ))"

libperf-y += util/
libperf-y += arch/
diff --git a/tools/perf/Documentation/tips.txt b/tools/perf/Documentation/tips.txt
new file mode 100644
index 000000000000..383aef8f9509
--- /dev/null
+++ b/tools/perf/Documentation/tips.txt
@@ -0,0 +1,14 @@
+For a higher level overview, try: perf report --sort comm,dso
+Group related events with: perf record -e '{cycles,instructions}:S'
+Compare performance results with: perf diff [<old file> <new file>]
+Boolean options have negative forms like: 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
+Create archive of data to see it 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>
+listing interested 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 location
+To see callchains in a more compact form: perf report -g folded
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 404e3b1c4e31..964cf1201541 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -567,6 +567,9 @@ endif
$(call QUIET_INSTALL, perf_completion-script) \
$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(sysconfdir_SQ)/bash_completion.d'; \
$(INSTALL) perf-completion.sh '$(DESTDIR_SQ)$(sysconfdir_SQ)/bash_completion.d/perf'
+ $(call QUIET_INSTALL, perf-tip) \
+ $(INSTALL) -d -m 755 '$(DESTDIR_SQ)$(tip_instdir_SQ)'; \
+ $(INSTALL) Documentation/tips.txt -t '$(DESTDIR_SQ)$(tip_instdir_SQ)'

install-tests: all install-gtk
$(call QUIET_INSTALL, tests) \
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f10c663af996..965143c98265 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -433,7 +433,7 @@ static int report__browse_hists(struct report *rep)
int ret;
struct perf_session *session = rep->session;
struct perf_evlist *evlist = session->evlist;
- const char *help = "For a higher level overview, try: perf report --sort comm,dso";
+ const char *help = perf_report_tip(TIPDIR);

switch (use_browser) {
case 1:
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile
index 18b2f96d0941..254d06e39bea 100644
--- a/tools/perf/config/Makefile
+++ b/tools/perf/config/Makefile
@@ -691,6 +691,7 @@ sharedir = $(prefix)/share
template_dir = share/perf-core/templates
STRACE_GROUPS_DIR = share/perf-core/strace/groups
htmldir = share/doc/perf-doc
+tipdir = share/doc/perf-tip
ifeq ($(prefix),/usr)
sysconfdir = /etc
ETC_PERFCONFIG = $(sysconfdir)/perfconfig
@@ -717,6 +718,7 @@ infodir_SQ = $(subst ','\'',$(infodir))
perfexecdir_SQ = $(subst ','\'',$(perfexecdir))
template_dir_SQ = $(subst ','\'',$(template_dir))
htmldir_SQ = $(subst ','\'',$(htmldir))
+tipdir_SQ = $(subst ','\'',$(tipdir))
prefix_SQ = $(subst ','\'',$(prefix))
sysconfdir_SQ = $(subst ','\'',$(sysconfdir))
libdir_SQ = $(subst ','\'',$(libdir))
@@ -724,12 +726,15 @@ libdir_SQ = $(subst ','\'',$(libdir))
ifneq ($(filter /%,$(firstword $(perfexecdir))),)
perfexec_instdir = $(perfexecdir)
STRACE_GROUPS_INSTDIR = $(STRACE_GROUPS_DIR)
+tip_instdir = $(tipdir)
else
perfexec_instdir = $(prefix)/$(perfexecdir)
STRACE_GROUPS_INSTDIR = $(prefix)/$(STRACE_GROUPS_DIR)
+tip_instdir = $(prefix)/$(tipdir)
endif
perfexec_instdir_SQ = $(subst ','\'',$(perfexec_instdir))
STRACE_GROUPS_INSTDIR_SQ = $(subst ','\'',$(STRACE_GROUPS_INSTDIR))
+tip_instdir_SQ = $(subst ','\'',$(tip_instdir))

# If we install to $(HOME) we keep the traceevent default:
# $(HOME)/.traceevent/plugins
@@ -770,6 +775,7 @@ $(call detected_var,ETC_PERFCONFIG_SQ)
$(call detected_var,STRACE_GROUPS_DIR_SQ)
$(call detected_var,prefix_SQ)
$(call detected_var,perfexecdir_SQ)
+$(call detected_var,tipdir_SQ)
$(call detected_var,LIBDIR)
$(call detected_var,GTK_CFLAGS)
$(call detected_var,PERL_EMBED_CCOPTS)
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index cb1d2499c45c..a929618b8eb6 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 @@ int main(int argc, const char **argv)
if (!cmd)
cmd = "perf-help";

+ srandom(time(NULL));
+
/* get debugfs/tracefs mount point from /proc/mounts */
tracing_path_mount();

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index aff0cfd83662..23ad4ba08aa4 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_report_tip(const char *dirname)
+{
+ struct strlist *tips;
+ struct str_node *node;
+ char *tip = NULL;
+ struct strlist_config conf = {
+ .dirname = system_path(dirname) ,
+ };
+
+ 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..d8fc48e76139 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_report_tip(const char *dirname);
+
#endif /* GIT_COMPAT_UTIL_H */
--
2.6.4

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