1 files changed, 41 insertions, 15 deletions

diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 99a12fe86e9f..2459e5a22ed8 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -48,6 +48,8 @@ static int			call_graph			= 0;
 static int			inherit_stat			= 0;
 static int			no_samples			= 0;
 static int			sample_address			= 0;
+static int			multiplex			= 0;
+static int			multiplex_fd			= -1;
 
 static long			samples;
 static struct timeval		last_read;
@@ -470,19 +472,28 @@ try_again:
 	 */
 	if (group && group_fd == -1)
 		group_fd = fd[nr_cpu][counter];
+	if (multiplex && multiplex_fd == -1)
+		multiplex_fd = fd[nr_cpu][counter];
 
-	event_array[nr_poll].fd = fd[nr_cpu][counter];
-	event_array[nr_poll].events = POLLIN;
-	nr_poll++;
-
-	mmap_array[nr_cpu][counter].counter = counter;
-	mmap_array[nr_cpu][counter].prev = 0;
-	mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
-	mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
-			PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
-	if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
-		error("failed to mmap with %d (%s)\n", errno, strerror(errno));
-		exit(-1);
+	if (multiplex && fd[nr_cpu][counter] != multiplex_fd) {
+		int ret;
+
+		ret = ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_SET_OUTPUT, multiplex_fd);
+		assert(ret != -1);
+	} else {
+		event_array[nr_poll].fd = fd[nr_cpu][counter];
+		event_array[nr_poll].events = POLLIN;
+		nr_poll++;
+
+		mmap_array[nr_cpu][counter].counter = counter;
+		mmap_array[nr_cpu][counter].prev = 0;
+		mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1;
+		mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
+				PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0);
+		if (mmap_array[nr_cpu][counter].base == MAP_FAILED) {
+			error("failed to mmap with %d (%s)\n", errno, strerror(errno));
+			exit(-1);
+		}
 	}
 
 	ioctl(fd[nr_cpu][counter], PERF_COUNTER_IOC_ENABLE);
@@ -513,6 +524,7 @@ static int __cmd_record(int argc, const char **argv)
 	pid_t pid = 0;
 	int flags;
 	int ret;
+	unsigned long waking = 0;
 
 	page_size = sysconf(_SC_PAGE_SIZE);
 	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
@@ -614,17 +626,29 @@ static int __cmd_record(int argc, const char **argv)
 		int hits = samples;
 
 		for (i = 0; i < nr_cpu; i++) {
-			for (counter = 0; counter < nr_counters; counter++)
-				mmap_read(&mmap_array[i][counter]);
+			for (counter = 0; counter < nr_counters; counter++) {
+				if (mmap_array[i][counter].base)
+					mmap_read(&mmap_array[i][counter]);
+			}
 		}
 
 		if (hits == samples) {
 			if (done)
 				break;
-			ret = poll(event_array, nr_poll, 100);
+			ret = poll(event_array, nr_poll, -1);
+			waking++;
+		}
+
+		if (done) {
+			for (i = 0; i < nr_cpu; i++) {
+				for (counter = 0; counter < nr_counters; counter++)
+					ioctl(fd[i][counter], PERF_COUNTER_IOC_DISABLE);
+			}
 		}
 	}
 
+	fprintf(stderr, "[ perf record: Woken up %ld times to write data ]\n", waking);
+
 	/*
 	 * Approximate RIP event size: 24 bytes.
 	 */
@@ -681,6 +705,8 @@ static const struct option options[] = {
 		    "Sample addresses"),
 	OPT_BOOLEAN('n', "no-samples", &no_samples,
 		    "don't sample"),
+	OPT_BOOLEAN('M', "multiplex", &multiplex,
+		    "multiplex counter output in a single channel"),
 	OPT_END()
 };