perf mem: enable simultaneous sampling of loads/stores

This patch modifies perf mem to default to sampling loads and stores simultaneously. It could only do one or the other before yet there was not hardware restriction preventing simultaneous collection. With this patch, one run is sufficient to collect both.

By default load/stores are sampled now:

$ perf mem rec
$ perf mem rep

It is still possible to sample only loads or stores by using the -t option:

 $ perf mem -t load rec
 $ perf mem -t load rep
Or
 $ perf mem -t store rec
 $ perf mem -t store rep

The perf report TUI will show one event at a time. The store output will contain a Weight column which will be empty.

Signed-off-by Stephane Eranian <[email protected]>

---
 tools/perf/builtin-mem.c | 107 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 92 insertions(+), 15 deletions(-)

tools/perf/builtin-mem.c +92 -15

index 24db6ff..52dbaae 100644
@@ -7,10 +7,13 @@
 #include "util/session.h"
 #include "util/data.h"
 
-#define MEM_OPERATION_LOAD	"load"
-#define MEM_OPERATION_STORE	"store"
+#define MEM_OPERATION_LOAD	0x1
+#define MEM_OPERATION_STORE	0x2
 
-static const char	*mem_operation		= MEM_OPERATION_LOAD;
+/*
+ * default to both load an store sampling
+ */
+static int mem_operation = MEM_OPERATION_LOAD | MEM_OPERATION_STORE;
 
 struct perf_mem {
 	struct perf_tool	tool;

@@ -25,26 +28,30 @@ static int __cmd_record(int argc, const char **argv)
 {
 	int rec_argc, i = 0, j;
 	const char **rec_argv;
-	char event[64];
 	int ret;
 
-	rec_argc = argc + 4;
+	rec_argc = argc + 7; /* max number of arguments */
 	rec_argv = calloc(rec_argc + 1, sizeof(char *));
 	if (!rec_argv)
 		return -1;
 
 	rec_argv[i++] = strdup("record");
-	if (!strcmp(mem_operation, MEM_OPERATION_LOAD))
+
+	if (mem_operation & MEM_OPERATION_LOAD)
 		rec_argv[i++] = strdup("-W");
+
 	rec_argv[i++] = strdup("-d");
-	rec_argv[i++] = strdup("-e");
 
-	if (strcmp(mem_operation, MEM_OPERATION_LOAD))
-		sprintf(event, "cpu/mem-stores/pp");
-	else
-		sprintf(event, "cpu/mem-loads/pp");
+	if (mem_operation & MEM_OPERATION_LOAD) {
+		rec_argv[i++] = strdup("-e");
+		rec_argv[i++] = strdup("cpu/mem-loads/pp");
+	}
+
+	if (mem_operation & MEM_OPERATION_STORE) {
+		rec_argv[i++] = strdup("-e");
+		rec_argv[i++] = strdup("cpu/mem-stores/pp");
+	}
 
-	rec_argv[i++] = strdup(event);
 	for (j = 1; j < argc; j++, i++)
 		rec_argv[i] = argv[j];
 

@@ -170,7 +177,7 @@ static int report_events(int argc, const char **argv, struct perf_mem *mem)
 	 * there is no weight (cost) associated with stores, so don't print
 	 * the column
 	 */
-	if (strcmp(mem_operation, MEM_OPERATION_LOAD))
+	if (!(mem_operation & MEM_OPERATION_LOAD))
 		rep_argv[i++] = strdup("--sort=mem,sym,dso,symbol_daddr,"
 				       "dso_daddr,tlb,locked");
 

@@ -182,6 +189,75 @@ static int report_events(int argc, const char **argv, struct perf_mem *mem)
 	return ret;
 }
 
+struct mem_mode {
+	const char *name;
+	int mode;
+};
+
+#define MEM_OPT(n, m) \
+	{ .name = n, .mode = (m) }
+
+#define MEM_END { .name = NULL }
+
+static const struct mem_mode mem_modes[]={
+	MEM_OPT("load", MEM_OPERATION_LOAD),
+	MEM_OPT("store", MEM_OPERATION_STORE),
+	MEM_END
+};
+
+static int
+parse_mem_ops(const struct option *opt, const char *str, int unset)
+{
+	int *mode = (int *)opt->value;
+	const struct mem_mode *m;
+	char *s, *os = NULL, *p;
+	int ret = -1;
+
+	if (unset)
+		return 0;
+
+	/* str may be NULL in case no arg is passed to -t */
+	if (str) {
+		/* because str is read-only */
+		s = os = strdup(str);
+		if (!s)
+			return -1;
+
+		/* reset mode */
+		*mode = 0;
+
+		for (;;) {
+			p = strchr(s, ',');
+			if (p)
+				*p = '\0';
+
+			for (m = mem_modes; m->name; m++) {
+				if (!strcasecmp(s, m->name))
+					break;
+			}
+			if (!m->name) {
+				fprintf(stderr, "unknown sampling op %s,"
+					    " check man page\n", s);
+				goto error;
+			}
+
+			*mode |= m->mode;
+
+			if (!p)
+				break;
+
+			s = p + 1;
+		}
+	}
+	ret = 0;
+
+	if (*mode == 0)
+		*mode = MEM_OPERATION_LOAD;
+error:
+	free(os);
+	return ret;
+}
+
 int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	struct stat st;

@@ -199,8 +275,9 @@ int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
 		.input_name		 = "perf.data",
 	};
 	const struct option mem_options[] = {
-	OPT_STRING('t', "type", &mem_operation,
-		   "type", "memory operations(load/store)"),
+	OPT_CALLBACK('t', "type", &mem_operation,
+		   "type", "memory operations(load,store) Default load,store",
+		    parse_mem_ops),
 	OPT_BOOLEAN('D', "dump-raw-samples", &mem.dump_raw,
 		    "dump raw samples in ASCII"),
 	OPT_BOOLEAN('U', "hide-unresolved", &mem.hide_unresolved,

Signature · 1 line

1.9.1

Em Tue, Dec 16, 2014 at 05:53:58PM +0100, Stephane Eranian escreveu:

Quoted 19 lines

This patch modifies perf mem to default to sampling loads and stores simultaneously. It could only do one or the other before yet there was not hardware restriction preventing simultaneous collection. With this patch, one run is sufficient to collect both.

By default load/stores are sampled now:

$ perf mem rec
$ perf mem rep

It is still possible to sample only loads or stores by using the -t option:

 $ perf mem -t load rec
 $ perf mem -t load rep
Or
 $ perf mem -t store rec
 $ perf mem -t store rep

Quoted 2 lines

The perf report TUI will show one event at a time. The store output will contain a Weight column which will be empty.

Can you please update the man page and resubmit?

Are those unchecked strdups really needed?

- Arnaldo

Quoted 165 lines

Signed-off-by Stephane Eranian <[email protected]>

---
 tools/perf/builtin-mem.c | 107 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 92 insertions(+), 15 deletions(-)

tools/perf/builtin-mem.c +92 -16

index 24db6ff..52dbaae 100644
@@ -7,10 +7,13 @@
 #include "util/session.h"
 #include "util/data.h"
 
-#define MEM_OPERATION_LOAD   "load"
-#define MEM_OPERATION_STORE  "store"
+#define MEM_OPERATION_LOAD   0x1
+#define MEM_OPERATION_STORE  0x2
 
-static const char    *mem_operation          = MEM_OPERATION_LOAD;
+/*
+ * default to both load an store sampling
+ */
+static int mem_operation = MEM_OPERATION_LOAD | MEM_OPERATION_STORE;
 
 struct perf_mem {
      struct perf_tool        tool;

@@ -25,26 +28,30 @@ static int __cmd_record(int argc, const char **argv)
 {
      int rec_argc, i = 0, j;
      const char **rec_argv;
-     char event[64];
      int ret;
 
-     rec_argc = argc + 4;
+     rec_argc = argc + 7; /* max number of arguments */
      rec_argv = calloc(rec_argc + 1, sizeof(char *));
      if (!rec_argv)
              return -1;
 
      rec_argv[i++] = strdup("record");
-     if (!strcmp(mem_operation, MEM_OPERATION_LOAD))
+
+     if (mem_operation & MEM_OPERATION_LOAD)
              rec_argv[i++] = strdup("-W");
+
      rec_argv[i++] = strdup("-d");
-     rec_argv[i++] = strdup("-e");
 
-     if (strcmp(mem_operation, MEM_OPERATION_LOAD))
-             sprintf(event, "cpu/mem-stores/pp");
-     else
-             sprintf(event, "cpu/mem-loads/pp");
+     if (mem_operation & MEM_OPERATION_LOAD) {
+             rec_argv[i++] = strdup("-e");
+             rec_argv[i++] = strdup("cpu/mem-loads/pp");
+     }
+
+     if (mem_operation & MEM_OPERATION_STORE) {
+             rec_argv[i++] = strdup("-e");
+             rec_argv[i++] = strdup("cpu/mem-stores/pp");
+     }
 
-     rec_argv[i++] = strdup(event);
      for (j = 1; j < argc; j++, i++)
              rec_argv[i] = argv[j];
 

@@ -170,7 +177,7 @@ static int report_events(int argc, const char **argv, struct perf_mem *mem)
       * there is no weight (cost) associated with stores, so don't print
       * the column
       */
-     if (strcmp(mem_operation, MEM_OPERATION_LOAD))
+     if (!(mem_operation & MEM_OPERATION_LOAD))
              rep_argv[i++] = strdup("--sort=mem,sym,dso,symbol_daddr,"
                                     "dso_daddr,tlb,locked");
 

@@ -182,6 +189,75 @@ static int report_events(int argc, const char **argv, struct perf_mem *mem)
      return ret;
 }
 
+struct mem_mode {
+     const char *name;
+     int mode;
+};
+
+#define MEM_OPT(n, m) \
+     { .name = n, .mode = (m) }
+
+#define MEM_END { .name = NULL }
+
+static const struct mem_mode mem_modes[]={
+     MEM_OPT("load", MEM_OPERATION_LOAD),
+     MEM_OPT("store", MEM_OPERATION_STORE),
+     MEM_END
+};
+
+static int
+parse_mem_ops(const struct option *opt, const char *str, int unset)
+{
+     int *mode = (int *)opt->value;
+     const struct mem_mode *m;
+     char *s, *os = NULL, *p;
+     int ret = -1;
+
+     if (unset)
+             return 0;
+
+     /* str may be NULL in case no arg is passed to -t */
+     if (str) {
+             /* because str is read-only */
+             s = os = strdup(str);
+             if (!s)
+                     return -1;
+
+             /* reset mode */
+             *mode = 0;
+
+             for (;;) {
+                     p = strchr(s, ',');
+                     if (p)
+                             *p = '\0';
+
+                     for (m = mem_modes; m->name; m++) {
+                             if (!strcasecmp(s, m->name))
+                                     break;
+                     }
+                     if (!m->name) {
+                             fprintf(stderr, "unknown sampling op %s,"
+                                         " check man page\n", s);
+                             goto error;
+                     }
+
+                     *mode |= m->mode;
+
+                     if (!p)
+                             break;
+
+                     s = p + 1;
+             }
+     }
+     ret = 0;
+
+     if (*mode == 0)
+             *mode = MEM_OPERATION_LOAD;
+error:
+     free(os);
+     return ret;
+}
+
 int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
 {
      struct stat st;

@@ -199,8 +275,9 @@ int cmd_mem(int argc, const char **argv, const char *prefix __maybe_unused)
              .input_name              = "perf.data",
      };
      const struct option mem_options[] = {
-     OPT_STRING('t', "type", &mem_operation,
-                "type", "memory operations(load/store)"),
+     OPT_CALLBACK('t', "type", &mem_operation,
+                "type", "memory operations(load,store) Default load,store",
+                 parse_mem_ops),
      OPT_BOOLEAN('D', "dump-raw-samples", &mem.dump_raw,
                  "dump raw samples in ASCII"),
      OPT_BOOLEAN('U', "hide-unresolved", &mem.hide_unresolved,
--

1.9.1