[PATCHv2 0/3] perf tools: Add perf_event_max_sample_rate freq check

[PATCHv2 0/3] perf tools: Add perf_event_max_sample_rate freq check

[Jiri Olsa]

hi,
adding the check for maximum allowed frequency rate
defined in perf_event_max_sample_rate.

Plus procfs mountpoint reading code. Reachable here:
  git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  perf/max_rate

v2 changes:
  naming changes suggested by Arnaldo in patch 1/3
  patch 3/3:
    - unify freq. config code for record and top
    - add warning for default rate crossing the max

jirka   

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Don Zickus <dzickus@redhat.com>
---
Jiri Olsa (3):
      perf tools: Factor sysfs code into generic fs object
      perf tools: Add procfs support into fs object
      perf tools: Check maximum frequency rate for record/top

 tools/perf/Makefile.perf              |   4 ++--
 tools/perf/builtin-record.c           |  15 +-----------
 tools/perf/builtin-top.c              |  15 +-----------
 tools/perf/tests/parse-events.c       |   2 +-
 tools/perf/util/cpumap.c              |   2 +-
 tools/perf/util/evlist.h              |   1 +
 tools/perf/util/fs.c                  | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/fs.h                  |   7 ++++++
 tools/perf/util/include/linux/magic.h |   4 ++++
 tools/perf/util/pmu.c                 |   2 +-
 tools/perf/util/python-ext-sources    |   2 +-
 tools/perf/util/record.c              |  72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/sysfs.c               |  60 -----------------------------------------------
 tools/perf/util/sysfs.h               |   6 -----
 14 files changed, 211 insertions(+), 100 deletions(-)
 create mode 100644 tools/perf/util/fs.c
 create mode 100644 tools/perf/util/fs.h
 delete mode 100644 tools/perf/util/sysfs.c
 delete mode 100644 tools/perf/util/sysfs.h

[PATCH 1/3] perf tools: Factor sysfs code into generic fs object

[Jiri Olsa]

Moving sysfs code into generic fs object and preparing
it to carry procfs support.

This should be merged with tools/lib/lk/debugfs.c at
some point in the future.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Makefile.perf           |   4 +-
 tools/perf/tests/parse-events.c    |   2 +-
 tools/perf/util/cpumap.c           |   2 +-
 tools/perf/util/fs.c               | 107 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/fs.h               |   6 +++
 tools/perf/util/pmu.c              |   2 +-
 tools/perf/util/python-ext-sources |   2 +-
 tools/perf/util/sysfs.c            |  60 ---------------------
 tools/perf/util/sysfs.h            |   6 ---
 9 files changed, 119 insertions(+), 72 deletions(-)
 create mode 100644 tools/perf/util/fs.c
 create mode 100644 tools/perf/util/fs.h
 delete mode 100644 tools/perf/util/sysfs.c
 delete mode 100644 tools/perf/util/sysfs.h

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index bc7cfa1..f5d3251 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -242,7 +242,7 @@ LIB_H += util/cache.h
 LIB_H += util/callchain.h
 LIB_H += util/build-id.h
 LIB_H += util/debug.h
-LIB_H += util/sysfs.h
+LIB_H += util/fs.h
 LIB_H += util/pmu.h
 LIB_H += util/event.h
 LIB_H += util/evsel.h
@@ -303,7 +303,7 @@ LIB_OBJS += $(OUTPUT)util/annotate.o
 LIB_OBJS += $(OUTPUT)util/build-id.o
 LIB_OBJS += $(OUTPUT)util/config.o
 LIB_OBJS += $(OUTPUT)util/ctype.o
-LIB_OBJS += $(OUTPUT)util/sysfs.o
+LIB_OBJS += $(OUTPUT)util/fs.o
 LIB_OBJS += $(OUTPUT)util/pmu.o
 LIB_OBJS += $(OUTPUT)util/environment.o
 LIB_OBJS += $(OUTPUT)util/event.o
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 48114d1..f47bf45 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -2,7 +2,7 @@
 #include "parse-events.h"
 #include "evsel.h"
 #include "evlist.h"
-#include "sysfs.h"
+#include "fs.h"
 #include <lk/debugfs.h>
 #include "tests.h"
 #include <linux/hw_breakpoint.h>
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index beb8cf9..4af5a23 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -1,5 +1,5 @@
 #include "util.h"
-#include "sysfs.h"
+#include "fs.h"
 #include "../perf.h"
 #include "cpumap.h"
 #include <assert.h>
diff --git a/tools/perf/util/fs.c b/tools/perf/util/fs.c
new file mode 100644
index 0000000..ff7066c
--- /dev/null
+++ b/tools/perf/util/fs.c
@@ -0,0 +1,107 @@
+
+/* TODO merge/factor into tools/lib/lk/debugfs.c */
+
+#include "util.h"
+#include "util/fs.h"
+
+static const char * const sysfs_known_mountpoints[] = {
+	"/sys",
+	0,
+};
+
+struct fs {
+	const char		*name;
+	const char * const	*mounts;
+	char			 path[PATH_MAX + 1];
+	bool			 found;
+	long			 magic;
+};
+
+enum {
+	FS__SYSFS = 0,
+};
+
+static struct fs fs_entries[] = {
+	[FS__SYSFS] = {
+		.name	= "sysfs",
+		.mounts	= sysfs_known_mountpoints,
+		.magic	= SYSFS_MAGIC,
+	},
+};
+
+static bool read_mounts(struct fs *fs)
+{
+	bool found = false;
+	char type[100];
+	FILE *fp;
+
+	fp = fopen("/proc/mounts", "r");
+	if (fp == NULL)
+		return NULL;
+
+	while (!found &&
+	       fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
+		      fs->path, type) == 2) {
+
+		if (strcmp(type, fs->name) == 0)
+			found = true;
+	}
+
+	fclose(fp);
+	return fs->found = found;
+}
+
+static int valid_mount(const char *fs, long magic)
+{
+	struct statfs st_fs;
+
+	if (statfs(fs, &st_fs) < 0)
+		return -ENOENT;
+	else if (st_fs.f_type != magic)
+		return -ENOENT;
+
+	return 0;
+}
+
+static bool check_mounts(struct fs *fs)
+{
+	const char * const *ptr;
+
+	ptr = fs->mounts;
+	while (*ptr) {
+		if (valid_mount(*ptr, fs->magic) == 0) {
+			fs->found = true;
+			strcpy(fs->path, *ptr);
+			return true;
+		}
+		ptr++;
+	}
+
+	return false;
+}
+
+static const char *get_mountpoint(struct fs *fs)
+{
+	if (check_mounts(fs))
+		return fs->path;
+
+	return read_mounts(fs) ? fs->path : NULL;
+}
+
+static const char *find_mountpoint(int idx)
+{
+	struct fs *fs = &fs_entries[idx];
+
+	if (fs->found)
+		return (const char *) fs->path;
+
+	return get_mountpoint(fs);
+}
+
+#define FIND_MOUNTPOINT(name, idx)		\
+const char *name##_find_mountpoint(void)	\
+{						\
+	return find_mountpoint(idx);		\
+}
+
+FIND_MOUNTPOINT(sysfs, FS__SYSFS);
diff --git a/tools/perf/util/fs.h b/tools/perf/util/fs.h
new file mode 100644
index 0000000..082edbd
--- /dev/null
+++ b/tools/perf/util/fs.h
@@ -0,0 +1,6 @@
+#ifndef __PERF_FS
+#define __PERF_FS
+
+const char *sysfs_find_mountpoint(void);
+
+#endif /* __PERF_FS */
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 64362fe..45b42df 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -4,7 +4,7 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <dirent.h>
-#include "sysfs.h"
+#include "fs.h"
 #include "util.h"
 #include "pmu.h"
 #include "parse-events.h"
diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index f75ae1b..239036f 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -17,5 +17,5 @@ util/xyarray.c
 util/cgroup.c
 util/rblist.c
 util/strlist.c
-util/sysfs.c
+util/fs.c
 ../../lib/rbtree.c
diff --git a/tools/perf/util/sysfs.c b/tools/perf/util/sysfs.c
deleted file mode 100644
index f71e9ea..0000000
--- a/tools/perf/util/sysfs.c
+++ /dev/null
@@ -1,60 +0,0 @@
-
-#include "util.h"
-#include "sysfs.h"
-
-static const char * const sysfs_known_mountpoints[] = {
-	"/sys",
-	0,
-};
-
-static int sysfs_found;
-char sysfs_mountpoint[PATH_MAX + 1];
-
-static int sysfs_valid_mountpoint(const char *sysfs)
-{
-	struct statfs st_fs;
-
-	if (statfs(sysfs, &st_fs) < 0)
-		return -ENOENT;
-	else if (st_fs.f_type != (long) SYSFS_MAGIC)
-		return -ENOENT;
-
-	return 0;
-}
-
-const char *sysfs_find_mountpoint(void)
-{
-	const char * const *ptr;
-	char type[100];
-	FILE *fp;
-
-	if (sysfs_found)
-		return (const char *) sysfs_mountpoint;
-
-	ptr = sysfs_known_mountpoints;
-	while (*ptr) {
-		if (sysfs_valid_mountpoint(*ptr) == 0) {
-			sysfs_found = 1;
-			strcpy(sysfs_mountpoint, *ptr);
-			return sysfs_mountpoint;
-		}
-		ptr++;
-	}
-
-	/* give up and parse /proc/mounts */
-	fp = fopen("/proc/mounts", "r");
-	if (fp == NULL)
-		return NULL;
-
-	while (!sysfs_found &&
-	       fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
-		      sysfs_mountpoint, type) == 2) {
-
-		if (strcmp(type, "sysfs") == 0)
-			sysfs_found = 1;
-	}
-
-	fclose(fp);
-
-	return sysfs_found ? sysfs_mountpoint : NULL;
-}
diff --git a/tools/perf/util/sysfs.h b/tools/perf/util/sysfs.h
deleted file mode 100644
index a813b72..0000000
--- a/tools/perf/util/sysfs.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __SYSFS_H__
-#define __SYSFS_H__
-
-const char *sysfs_find_mountpoint(void);
-
-#endif /* __DEBUGFS_H__ */
-- 
1.8.3.1

[PATCH 2/3] perf tools: Add procfs support into fs object

[Jiri Olsa]

Adding procfs support into fs object.

The interface function:
  const char *procfs_find_mountpoint(void);

provides valid mountpoint path for procfs.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/fs.c                  | 16 ++++++++++++++--
 tools/perf/util/fs.h                  |  1 +
 tools/perf/util/include/linux/magic.h |  4 ++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/fs.c b/tools/perf/util/fs.c
index ff7066c..604f64e 100644
--- a/tools/perf/util/fs.c
+++ b/tools/perf/util/fs.c
@@ -9,6 +9,11 @@ static const char * const sysfs_known_mountpoints[] = {
 	0,
 };
 
+static const char * const procfs_known_mountpoints[] = {
+	"/proc",
+	0,
+};
+
 struct fs {
 	const char		*name;
 	const char * const	*mounts;
@@ -18,7 +23,8 @@ struct fs {
 };
 
 enum {
-	FS__SYSFS = 0,
+	FS__SYSFS  = 0,
+	FS__PROCFS = 1,
 };
 
 static struct fs fs_entries[] = {
@@ -27,6 +33,11 @@ static struct fs fs_entries[] = {
 		.mounts	= sysfs_known_mountpoints,
 		.magic	= SYSFS_MAGIC,
 	},
+	[FS__PROCFS] = {
+		.name	= "proc",
+		.mounts	= procfs_known_mountpoints,
+		.magic	= PROC_SUPER_MAGIC,
+	},
 };
 
 static bool read_mounts(struct fs *fs)
@@ -104,4 +115,5 @@ const char *name##_find_mountpoint(void)	\
 	return find_mountpoint(idx);		\
 }
 
-FIND_MOUNTPOINT(sysfs, FS__SYSFS);
+FIND_MOUNTPOINT(sysfs,  FS__SYSFS);
+FIND_MOUNTPOINT(procfs, FS__PROCFS);
diff --git a/tools/perf/util/fs.h b/tools/perf/util/fs.h
index 082edbd..bc6556f 100644
--- a/tools/perf/util/fs.h
+++ b/tools/perf/util/fs.h
@@ -2,5 +2,6 @@
 #define __PERF_FS
 
 const char *sysfs_find_mountpoint(void);
+const char *procfs_find_mountpoint(void);
 
 #endif /* __PERF_FS */
diff --git a/tools/perf/util/include/linux/magic.h b/tools/perf/util/include/linux/magic.h
index 58b64ed..07d63cf 100644
--- a/tools/perf/util/include/linux/magic.h
+++ b/tools/perf/util/include/linux/magic.h
@@ -9,4 +9,8 @@
 #define SYSFS_MAGIC            0x62656572
 #endif
 
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC       0x9fa0
+#endif
+
 #endif
-- 
1.8.3.1

[PATCH 3/3] perf tools: Check maximum frequency rate for record/top

[Jiri Olsa]

Adding the check for maximum allowed frequency rate
defined in following file:
  /proc/sys/kernel/perf_event_max_sample_rate

When we cross the maximum value we fail and display
detailed error message with advise.

  $ perf record -F 3000 ls
  Maximum frequency rate (2000) reached.
  Please use -F freq option with lower value or consider
  tweaking /proc/sys/kernel/perf_event_max_sample_rate.

In case user does not specify the frequency and
the default value cross the maximum, we display
warning and set the frequency value to the
current maximum.

  $ perf record ls
  Lowering default frequency rate to 2000.
  Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.

Same messages are used for 'perf top'.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-record.c | 15 +---------
 tools/perf/builtin-top.c    | 15 +---------
 tools/perf/util/evlist.h    |  1 +
 tools/perf/util/record.c    | 72 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 75 insertions(+), 28 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index ab8d15e..4eaae4b 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -929,20 +929,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (perf_evlist__create_maps(evsel_list, &rec->opts.target) < 0)
 		usage_with_options(record_usage, record_options);
 
-	if (rec->opts.user_interval != ULLONG_MAX)
-		rec->opts.default_interval = rec->opts.user_interval;
-	if (rec->opts.user_freq != UINT_MAX)
-		rec->opts.freq = rec->opts.user_freq;
-
-	/*
-	 * User specified count overrides default frequency.
-	 */
-	if (rec->opts.default_interval)
-		rec->opts.freq = 0;
-	else if (rec->opts.freq) {
-		rec->opts.default_interval = rec->opts.freq;
-	} else {
-		ui__error("frequency and count are zero, aborting\n");
+	if (perf_opts__config(&rec->opts)) {
 		err = -EINVAL;
 		goto out_free_fd;
 	}
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 04f5bf2..8736cb3 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1203,20 +1203,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (top.delay_secs < 1)
 		top.delay_secs = 1;
 
-	if (opts->user_interval != ULLONG_MAX)
-		opts->default_interval = opts->user_interval;
-	if (opts->user_freq != UINT_MAX)
-		opts->freq = opts->user_freq;
-
-	/*
-	 * User specified count overrides default frequency.
-	 */
-	if (opts->default_interval)
-		opts->freq = 0;
-	else if (opts->freq) {
-		opts->default_interval = opts->freq;
-	} else {
-		ui__error("frequency and count are zero, aborting\n");
+	if (perf_opts__config(opts)) {
 		status = -EINVAL;
 		goto out_delete_maps;
 	}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 6e8acc9..ebd6409 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -99,6 +99,7 @@ void perf_evlist__set_id_pos(struct perf_evlist *evlist);
 bool perf_can_sample_identifier(void);
 void perf_evlist__config(struct perf_evlist *evlist,
 			 struct perf_record_opts *opts);
+int perf_opts__config(struct perf_record_opts *opts);
 
 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
 				  struct perf_target *target,
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 18d73aa..1569641 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -2,6 +2,8 @@
 #include "evsel.h"
 #include "cpumap.h"
 #include "parse-events.h"
+#include "fs.h"
+#include "util.h"
 
 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
 
@@ -106,3 +108,73 @@ void perf_evlist__config(struct perf_evlist *evlist,
 
 	perf_evlist__set_id_pos(evlist);
 }
+
+static int get_max_rate(unsigned int *rate)
+{
+	const char *procfs;
+	char path[PATH_MAX];
+
+	procfs = procfs_find_mountpoint();
+	if (!procfs)
+		return -1;
+
+	snprintf(path, PATH_MAX,
+		 "%s/sys/kernel/perf_event_max_sample_rate", procfs);
+
+	return filename__read_int(path, (int *) rate);
+}
+
+static int perf_opts__config_freq(struct perf_record_opts *opts)
+{
+	bool user_freq = opts->user_freq != UINT_MAX;
+	unsigned int max_rate;
+
+	if (opts->user_interval != ULLONG_MAX)
+		opts->default_interval = opts->user_interval;
+	if (user_freq)
+		opts->freq = opts->user_freq;
+
+	/*
+	 * User specified count overrides default frequency.
+	 */
+	if (opts->default_interval)
+		opts->freq = 0;
+	else if (opts->freq) {
+		opts->default_interval = opts->freq;
+	} else {
+		pr_err("frequency and count are zero, aborting\n");
+		return -1;
+	}
+
+	if (get_max_rate(&max_rate))
+		return 0;
+
+	/*
+	 * User specified frequency is over current maximum.
+	 */
+	if (user_freq && (max_rate < opts->freq)) {
+		pr_err("Maximum frequency rate (%u) reached.\n"
+		   "Please use -F freq option with lower value or consider\n"
+		   "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
+		   max_rate);
+		return -1;
+	}
+
+	/*
+	 * Default frequency is over current maximum.
+	 */
+	if (max_rate < opts->freq) {
+		pr_warning("Lowering default frequency rate to %u.\n"
+			   "Please consider tweaking "
+			   "/proc/sys/kernel/perf_event_max_sample_rate.\n",
+			   max_rate);
+		opts->freq = max_rate;
+	}
+
+	return 0;
+}
+
+int perf_opts__config(struct perf_record_opts *opts)
+{
+	return perf_opts__config_freq(opts);
+}
-- 
1.8.3.1

[tip:perf/core] perf tools: Factor sysfs code into generic fs object

[tip-bot for Jiri Olsa]

Commit-ID:  4299a549979783668d787959d61ba22b6b200877
Gitweb:     http://git.kernel.org/tip/4299a549979783668d787959d61ba22b6b200877
Author:     Jiri Olsa <jolsa@redhat.com>
AuthorDate: Tue, 5 Nov 2013 15:14:45 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 5 Nov 2013 14:44:26 -0300

perf tools: Factor sysfs code into generic fs object

Moving sysfs code into generic fs object and preparing it to carry
procfs support.

This should be merged with tools/lib/lk/debugfs.c at some point in the
future.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1383660887-1734-2-git-send-email-jolsa@redhat.com
[ Added fs__ namespace qualifier to some more functions ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/Makefile.perf           |   4 +-
 tools/perf/tests/parse-events.c    |   2 +-
 tools/perf/util/cpumap.c           |   2 +-
 tools/perf/util/fs.c               | 107 +++++++++++++++++++++++++++++++++++++
 tools/perf/util/fs.h               |   6 +++
 tools/perf/util/pmu.c              |   2 +-
 tools/perf/util/python-ext-sources |   2 +-
 tools/perf/util/sysfs.c            |  60 ---------------------
 tools/perf/util/sysfs.h            |   6 ---
 9 files changed, 119 insertions(+), 72 deletions(-)

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 5b86390..7fc8f17 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -242,7 +242,7 @@ LIB_H += util/cache.h
 LIB_H += util/callchain.h
 LIB_H += util/build-id.h
 LIB_H += util/debug.h
-LIB_H += util/sysfs.h
+LIB_H += util/fs.h
 LIB_H += util/pmu.h
 LIB_H += util/event.h
 LIB_H += util/evsel.h
@@ -304,7 +304,7 @@ LIB_OBJS += $(OUTPUT)util/annotate.o
 LIB_OBJS += $(OUTPUT)util/build-id.o
 LIB_OBJS += $(OUTPUT)util/config.o
 LIB_OBJS += $(OUTPUT)util/ctype.o
-LIB_OBJS += $(OUTPUT)util/sysfs.o
+LIB_OBJS += $(OUTPUT)util/fs.o
 LIB_OBJS += $(OUTPUT)util/pmu.o
 LIB_OBJS += $(OUTPUT)util/environment.o
 LIB_OBJS += $(OUTPUT)util/event.o
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 48114d1..f47bf45 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -2,7 +2,7 @@
 #include "parse-events.h"
 #include "evsel.h"
 #include "evlist.h"
-#include "sysfs.h"
+#include "fs.h"
 #include <lk/debugfs.h>
 #include "tests.h"
 #include <linux/hw_breakpoint.h>
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index beb8cf9..4af5a23 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -1,5 +1,5 @@
 #include "util.h"
-#include "sysfs.h"
+#include "fs.h"
 #include "../perf.h"
 #include "cpumap.h"
 #include <assert.h>
diff --git a/tools/perf/util/fs.c b/tools/perf/util/fs.c
new file mode 100644
index 0000000..a2413e8
--- /dev/null
+++ b/tools/perf/util/fs.c
@@ -0,0 +1,107 @@
+
+/* TODO merge/factor into tools/lib/lk/debugfs.c */
+
+#include "util.h"
+#include "util/fs.h"
+
+static const char * const sysfs__fs_known_mountpoints[] = {
+	"/sys",
+	0,
+};
+
+struct fs {
+	const char		*name;
+	const char * const	*mounts;
+	char			 path[PATH_MAX + 1];
+	bool			 found;
+	long			 magic;
+};
+
+enum {
+	FS__SYSFS = 0,
+};
+
+static struct fs fs__entries[] = {
+	[FS__SYSFS] = {
+		.name	= "sysfs",
+		.mounts	= sysfs__fs_known_mountpoints,
+		.magic	= SYSFS_MAGIC,
+	},
+};
+
+static bool fs__read_mounts(struct fs *fs)
+{
+	bool found = false;
+	char type[100];
+	FILE *fp;
+
+	fp = fopen("/proc/mounts", "r");
+	if (fp == NULL)
+		return NULL;
+
+	while (!found &&
+	       fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
+		      fs->path, type) == 2) {
+
+		if (strcmp(type, fs->name) == 0)
+			found = true;
+	}
+
+	fclose(fp);
+	return fs->found = found;
+}
+
+static int fs__valid_mount(const char *fs, long magic)
+{
+	struct statfs st_fs;
+
+	if (statfs(fs, &st_fs) < 0)
+		return -ENOENT;
+	else if (st_fs.f_type != magic)
+		return -ENOENT;
+
+	return 0;
+}
+
+static bool fs__check_mounts(struct fs *fs)
+{
+	const char * const *ptr;
+
+	ptr = fs->mounts;
+	while (*ptr) {
+		if (fs__valid_mount(*ptr, fs->magic) == 0) {
+			fs->found = true;
+			strcpy(fs->path, *ptr);
+			return true;
+		}
+		ptr++;
+	}
+
+	return false;
+}
+
+static const char *fs__get_mountpoint(struct fs *fs)
+{
+	if (fs__check_mounts(fs))
+		return fs->path;
+
+	return fs__read_mounts(fs) ? fs->path : NULL;
+}
+
+static const char *fs__find_mountpoint(int idx)
+{
+	struct fs *fs = &fs__entries[idx];
+
+	if (fs->found)
+		return (const char *)fs->path;
+
+	return fs__get_mountpoint(fs);
+}
+
+#define FIND_MOUNTPOINT(name, idx)		\
+const char *name##_find_mountpoint(void)	\
+{						\
+	return fs__find_mountpoint(idx);	\
+}
+
+FIND_MOUNTPOINT(sysfs, FS__SYSFS);
diff --git a/tools/perf/util/fs.h b/tools/perf/util/fs.h
new file mode 100644
index 0000000..082edbd
--- /dev/null
+++ b/tools/perf/util/fs.h
@@ -0,0 +1,6 @@
+#ifndef __PERF_FS
+#define __PERF_FS
+
+const char *sysfs_find_mountpoint(void);
+
+#endif /* __PERF_FS */
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 64362fe..45b42df 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -4,7 +4,7 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <dirent.h>
-#include "sysfs.h"
+#include "fs.h"
 #include "util.h"
 #include "pmu.h"
 #include "parse-events.h"
diff --git a/tools/perf/util/python-ext-sources b/tools/perf/util/python-ext-sources
index f75ae1b..239036f 100644
--- a/tools/perf/util/python-ext-sources
+++ b/tools/perf/util/python-ext-sources
@@ -17,5 +17,5 @@ util/xyarray.c
 util/cgroup.c
 util/rblist.c
 util/strlist.c
-util/sysfs.c
+util/fs.c
 ../../lib/rbtree.c
diff --git a/tools/perf/util/sysfs.c b/tools/perf/util/sysfs.c
deleted file mode 100644
index f71e9ea..0000000
--- a/tools/perf/util/sysfs.c
+++ /dev/null
@@ -1,60 +0,0 @@
-
-#include "util.h"
-#include "sysfs.h"
-
-static const char * const sysfs_known_mountpoints[] = {
-	"/sys",
-	0,
-};
-
-static int sysfs_found;
-char sysfs_mountpoint[PATH_MAX + 1];
-
-static int sysfs_valid_mountpoint(const char *sysfs)
-{
-	struct statfs st_fs;
-
-	if (statfs(sysfs, &st_fs) < 0)
-		return -ENOENT;
-	else if (st_fs.f_type != (long) SYSFS_MAGIC)
-		return -ENOENT;
-
-	return 0;
-}
-
-const char *sysfs_find_mountpoint(void)
-{
-	const char * const *ptr;
-	char type[100];
-	FILE *fp;
-
-	if (sysfs_found)
-		return (const char *) sysfs_mountpoint;
-
-	ptr = sysfs_known_mountpoints;
-	while (*ptr) {
-		if (sysfs_valid_mountpoint(*ptr) == 0) {
-			sysfs_found = 1;
-			strcpy(sysfs_mountpoint, *ptr);
-			return sysfs_mountpoint;
-		}
-		ptr++;
-	}
-
-	/* give up and parse /proc/mounts */
-	fp = fopen("/proc/mounts", "r");
-	if (fp == NULL)
-		return NULL;
-
-	while (!sysfs_found &&
-	       fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
-		      sysfs_mountpoint, type) == 2) {
-
-		if (strcmp(type, "sysfs") == 0)
-			sysfs_found = 1;
-	}
-
-	fclose(fp);
-
-	return sysfs_found ? sysfs_mountpoint : NULL;
-}
diff --git a/tools/perf/util/sysfs.h b/tools/perf/util/sysfs.h
deleted file mode 100644
index a813b72..0000000
--- a/tools/perf/util/sysfs.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef __SYSFS_H__
-#define __SYSFS_H__
-
-const char *sysfs_find_mountpoint(void);
-
-#endif /* __DEBUGFS_H__ */

[tip:perf/core] perf fs: Add procfs support

[tip-bot for Jiri Olsa]

Commit-ID:  a9862418547e818aa5842840aecfa81d733b97e9
Gitweb:     http://git.kernel.org/tip/a9862418547e818aa5842840aecfa81d733b97e9
Author:     Jiri Olsa <jolsa@redhat.com>
AuthorDate: Tue, 5 Nov 2013 15:14:46 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 5 Nov 2013 15:15:07 -0300

perf fs: Add procfs support

Adding procfs support into fs class.

The interface function:
  const char *procfs__mountpoint(void);

provides existing mountpoint path for procfs.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1383660887-1734-3-git-send-email-jolsa@redhat.com
[ Fixup namespace ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/fs.c                  | 16 ++++++++++++++--
 tools/perf/util/fs.h                  |  1 +
 tools/perf/util/include/linux/magic.h |  4 ++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/fs.c b/tools/perf/util/fs.c
index 77bac4e..f5be1f2 100644
--- a/tools/perf/util/fs.c
+++ b/tools/perf/util/fs.c
@@ -9,6 +9,11 @@ static const char * const sysfs__fs_known_mountpoints[] = {
 	0,
 };
 
+static const char * const procfs__known_mountpoints[] = {
+	"/proc",
+	0,
+};
+
 struct fs {
 	const char		*name;
 	const char * const	*mounts;
@@ -18,7 +23,8 @@ struct fs {
 };
 
 enum {
-	FS__SYSFS = 0,
+	FS__SYSFS  = 0,
+	FS__PROCFS = 1,
 };
 
 static struct fs fs__entries[] = {
@@ -27,6 +33,11 @@ static struct fs fs__entries[] = {
 		.mounts	= sysfs__fs_known_mountpoints,
 		.magic	= SYSFS_MAGIC,
 	},
+	[FS__PROCFS] = {
+		.name	= "proc",
+		.mounts	= procfs__known_mountpoints,
+		.magic	= PROC_SUPER_MAGIC,
+	},
 };
 
 static bool fs__read_mounts(struct fs *fs)
@@ -104,4 +115,5 @@ const char *name##__mountpoint(void)	\
 	return fs__mountpoint(idx);	\
 }
 
-FS__MOUNTPOINT(sysfs, FS__SYSFS);
+FS__MOUNTPOINT(sysfs,  FS__SYSFS);
+FS__MOUNTPOINT(procfs, FS__PROCFS);
diff --git a/tools/perf/util/fs.h b/tools/perf/util/fs.h
index a7561c8..5e09ce1 100644
--- a/tools/perf/util/fs.h
+++ b/tools/perf/util/fs.h
@@ -2,5 +2,6 @@
 #define __PERF_FS
 
 const char *sysfs__mountpoint(void);
+const char *procfs__mountpoint(void);
 
 #endif /* __PERF_FS */
diff --git a/tools/perf/util/include/linux/magic.h b/tools/perf/util/include/linux/magic.h
index 58b64ed..07d63cf 100644
--- a/tools/perf/util/include/linux/magic.h
+++ b/tools/perf/util/include/linux/magic.h
@@ -9,4 +9,8 @@
 #define SYSFS_MAGIC            0x62656572
 #endif
 
+#ifndef PROC_SUPER_MAGIC
+#define PROC_SUPER_MAGIC       0x9fa0
+#endif
+
 #endif

[tip:perf/core] perf tools: Check maximum frequency rate for record/top

[tip-bot for Jiri Olsa]

Commit-ID:  714647bdc516330e4405b39677d7f763e016c685
Gitweb:     http://git.kernel.org/tip/714647bdc516330e4405b39677d7f763e016c685
Author:     Jiri Olsa <jolsa@redhat.com>
AuthorDate: Tue, 5 Nov 2013 15:14:47 +0100
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 5 Nov 2013 15:15:08 -0300

perf tools: Check maximum frequency rate for record/top

Adding the check for maximum allowed frequency rate defined in following
file:

  /proc/sys/kernel/perf_event_max_sample_rate

When we cross the maximum value we fail and display detailed error
message with advise.

  $ perf record -F 3000 ls
  Maximum frequency rate (2000) reached.
  Please use -F freq option with lower value or consider
  tweaking /proc/sys/kernel/perf_event_max_sample_rate.

In case user does not specify the frequency and the default value cross
the maximum, we display warning and set the frequency value to the
current maximum.

  $ perf record ls
  Lowering default frequency rate to 2000.
  Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.

Same messages are used for 'perf top'.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1383660887-1734-4-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/builtin-record.c | 15 +---------
 tools/perf/builtin-top.c    | 15 +---------
 tools/perf/util/evlist.h    |  1 +
 tools/perf/util/record.c    | 71 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 74 insertions(+), 28 deletions(-)

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8b45fce..ea4c04f 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -958,20 +958,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (perf_evlist__create_maps(evsel_list, &rec->opts.target) < 0)
 		usage_with_options(record_usage, record_options);
 
-	if (rec->opts.user_interval != ULLONG_MAX)
-		rec->opts.default_interval = rec->opts.user_interval;
-	if (rec->opts.user_freq != UINT_MAX)
-		rec->opts.freq = rec->opts.user_freq;
-
-	/*
-	 * User specified count overrides default frequency.
-	 */
-	if (rec->opts.default_interval)
-		rec->opts.freq = 0;
-	else if (rec->opts.freq) {
-		rec->opts.default_interval = rec->opts.freq;
-	} else {
-		ui__error("frequency and count are zero, aborting\n");
+	if (perf_record_opts__config(&rec->opts)) {
 		err = -EINVAL;
 		goto out_free_fd;
 	}
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 21897f0..9acca88 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1209,20 +1209,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
 	if (top.delay_secs < 1)
 		top.delay_secs = 1;
 
-	if (opts->user_interval != ULLONG_MAX)
-		opts->default_interval = opts->user_interval;
-	if (opts->user_freq != UINT_MAX)
-		opts->freq = opts->user_freq;
-
-	/*
-	 * User specified count overrides default frequency.
-	 */
-	if (opts->default_interval)
-		opts->freq = 0;
-	else if (opts->freq) {
-		opts->default_interval = opts->freq;
-	} else {
-		ui__error("frequency and count are zero, aborting\n");
+	if (perf_record_opts__config(opts)) {
 		status = -EINVAL;
 		goto out_delete_maps;
 	}
diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
index 6e8acc9..0617ce2 100644
--- a/tools/perf/util/evlist.h
+++ b/tools/perf/util/evlist.h
@@ -99,6 +99,7 @@ void perf_evlist__set_id_pos(struct perf_evlist *evlist);
 bool perf_can_sample_identifier(void);
 void perf_evlist__config(struct perf_evlist *evlist,
 			 struct perf_record_opts *opts);
+int perf_record_opts__config(struct perf_record_opts *opts);
 
 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
 				  struct perf_target *target,
diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c
index 18d73aa..c8845b1 100644
--- a/tools/perf/util/record.c
+++ b/tools/perf/util/record.c
@@ -2,6 +2,8 @@
 #include "evsel.h"
 #include "cpumap.h"
 #include "parse-events.h"
+#include "fs.h"
+#include "util.h"
 
 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
 
@@ -106,3 +108,72 @@ void perf_evlist__config(struct perf_evlist *evlist,
 
 	perf_evlist__set_id_pos(evlist);
 }
+
+static int get_max_rate(unsigned int *rate)
+{
+	char path[PATH_MAX];
+	const char *procfs = procfs__mountpoint();
+
+	if (!procfs)
+		return -1;
+
+	snprintf(path, PATH_MAX,
+		 "%s/sys/kernel/perf_event_max_sample_rate", procfs);
+
+	return filename__read_int(path, (int *) rate);
+}
+
+static int perf_record_opts__config_freq(struct perf_record_opts *opts)
+{
+	bool user_freq = opts->user_freq != UINT_MAX;
+	unsigned int max_rate;
+
+	if (opts->user_interval != ULLONG_MAX)
+		opts->default_interval = opts->user_interval;
+	if (user_freq)
+		opts->freq = opts->user_freq;
+
+	/*
+	 * User specified count overrides default frequency.
+	 */
+	if (opts->default_interval)
+		opts->freq = 0;
+	else if (opts->freq) {
+		opts->default_interval = opts->freq;
+	} else {
+		pr_err("frequency and count are zero, aborting\n");
+		return -1;
+	}
+
+	if (get_max_rate(&max_rate))
+		return 0;
+
+	/*
+	 * User specified frequency is over current maximum.
+	 */
+	if (user_freq && (max_rate < opts->freq)) {
+		pr_err("Maximum frequency rate (%u) reached.\n"
+		   "Please use -F freq option with lower value or consider\n"
+		   "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
+		   max_rate);
+		return -1;
+	}
+
+	/*
+	 * Default frequency is over current maximum.
+	 */
+	if (max_rate < opts->freq) {
+		pr_warning("Lowering default frequency rate to %u.\n"
+			   "Please consider tweaking "
+			   "/proc/sys/kernel/perf_event_max_sample_rate.\n",
+			   max_rate);
+		opts->freq = max_rate;
+	}
+
+	return 0;
+}
+
+int perf_record_opts__config(struct perf_record_opts *opts)
+{
+	return perf_record_opts__config_freq(opts);
+}