1 files changed, 86 insertions, 29 deletions

diff --git a/tools/perf/bench/sched-pipe.c b/tools/perf/bench/sched-pipe.c
index 69cfba8d4c6c..07a8d7646a15 100644
--- a/tools/perf/bench/sched-pipe.c
+++ b/tools/perf/bench/sched-pipe.c
@@ -7,9 +7,7 @@
  * Based on pipe-test-1m.c by Ingo Molnar <mingo@redhat.com>
  *  http://people.redhat.com/mingo/cfs-scheduler/tools/pipe-test-1m.c
  * Ported to perf by Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
- *
  */
-
 #include "../perf.h"
 #include "../util/util.h"
 #include "../util/parse-options.h"
@@ -28,12 +26,24 @@
 #include <sys/time.h>
 #include <sys/types.h>
 
+#include <pthread.h>
+
+struct thread_data {
+        int                     nr;
+        int                     pipe_read;
+        int                     pipe_write;
+        pthread_t               pthread;
+};
+
 #define LOOPS_DEFAULT 1000000
-static int loops = LOOPS_DEFAULT;
+static  int                     loops = LOOPS_DEFAULT;
+
+/* Use processes by default: */
+static bool                     threaded;
 
 static const struct option options[] = {
-        OPT_INTEGER('l', "loop", &loops,
-                    "Specify number of loops"),
+        OPT_INTEGER('l', "loop",        &loops,         "Specify number of loops"),
+        OPT_BOOLEAN('T', "threaded",    &threaded,      "Specify threads/process based task setup"),
         OPT_END()
 };
 
@@ -42,13 +52,37 @@ static const char * const bench_sched_pipe_usage[] = {
         NULL
 };
 
-int bench_sched_pipe(int argc, const char **argv,
-                     const char *prefix __maybe_unused)
+static void *worker_thread(void *__tdata)
 {
-        int pipe_1[2], pipe_2[2];
+        struct thread_data *td = __tdata;
         int m = 0, i;
+        int ret;
+
+        for (i = 0; i < loops; i++) {
+                if (!td->nr) {
+                        ret = read(td->pipe_read, &m, sizeof(int));
+                        BUG_ON(ret != sizeof(int));
+                        ret = write(td->pipe_write, &m, sizeof(int));
+                        BUG_ON(ret != sizeof(int));
+                } else {
+                        ret = write(td->pipe_write, &m, sizeof(int));
+                        BUG_ON(ret != sizeof(int));
+                        ret = read(td->pipe_read, &m, sizeof(int));
+                        BUG_ON(ret != sizeof(int));
+                }
+        }
+
+        return NULL;
+}
+
+int bench_sched_pipe(int argc, const char **argv, const char *prefix __maybe_unused)
+{
+        struct thread_data threads[2], *td;
+        int pipe_1[2], pipe_2[2];
         struct timeval start, stop, diff;
         unsigned long long result_usec = 0;
+        int nr_threads = 2;
+        int t;
 
         /*
          * why does "ret" exist?
@@ -58,43 +92,66 @@ int bench_sched_pipe(int argc, const char **argv,
         int __maybe_unused ret, wait_stat;
         pid_t pid, retpid __maybe_unused;
 
-        argc = parse_options(argc, argv, options,
-                             bench_sched_pipe_usage, 0);
+        argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0);
 
         BUG_ON(pipe(pipe_1));
         BUG_ON(pipe(pipe_2));
 
-        pid = fork();
-        assert(pid >= 0);
-
         gettimeofday(&start, NULL);
 
-        if (!pid) {
-                for (i = 0; i < loops; i++) {
-                        ret = read(pipe_1[0], &m, sizeof(int));
-                        ret = write(pipe_2[1], &m, sizeof(int));
-                }
-        } else {
-                for (i = 0; i < loops; i++) {
-                        ret = write(pipe_1[1], &m, sizeof(int));
-                        ret = read(pipe_2[0], &m, sizeof(int));
+        for (t = 0; t < nr_threads; t++) {
+                td = threads + t;
+
+                td->nr = t;
+
+                if (t == 0) {
+                        td->pipe_read = pipe_1[0];
+                        td->pipe_write = pipe_2[1];
+                } else {
+                        td->pipe_write = pipe_1[1];
+                        td->pipe_read = pipe_2[0];
                 }
         }
 
-        gettimeofday(&stop, NULL);
-        timersub(&stop, &start, &diff);
 
-        if (pid) {
+        if (threaded) {
+
+                for (t = 0; t < nr_threads; t++) {
+                        td = threads + t;
+
+                        ret = pthread_create(&td->pthread, NULL, worker_thread, td);
+                        BUG_ON(ret);
+                }
+
+                for (t = 0; t < nr_threads; t++) {
+                        td = threads + t;
+
+                        ret = pthread_join(td->pthread, NULL);
+                        BUG_ON(ret);
+                }
+
+        } else {
+                pid = fork();
+                assert(pid >= 0);
+
+                if (!pid) {
+                        worker_thread(threads + 0);
+                        exit(0);
+                } else {
+                        worker_thread(threads + 1);
+                }
+
                 retpid = waitpid(pid, &wait_stat, 0);
                 assert((retpid == pid) && WIFEXITED(wait_stat));
-        } else {
-                exit(0);
         }
 
+        gettimeofday(&stop, NULL);
+        timersub(&stop, &start, &diff);
+
         switch (bench_format) {
         case BENCH_FORMAT_DEFAULT:
-                printf("# Executed %d pipe operations between two tasks\n\n",
-                        loops);
+                printf("# Executed %d pipe operations between two %s\n\n",
+                        loops, threaded ? "threads" : "processes");
 
                 result_usec = diff.tv_sec * 1000000;
                 result_usec += diff.tv_usec;