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perf bench sched: Add --threaded option

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Allow the measurement of thread versus process context switch
performance.

The default stays at 'process' based measurement, like lmbench's lat_ctx
benchmark.

Sample output:

 comet:~/tip/tools/perf> taskset 1 ./perf bench sched pipe
 # Running sched/pipe benchmark...
 # Executed 1000000 pipe operations between two processes

     Total time: 4.138 [sec]

       4.138729 usecs/op
         241620 ops/sec
 comet:~/tip/tools/perf> taskset 1 ./perf bench sched pipe --threaded
 # Running sched/pipe benchmark...
 # Executed 1000000 pipe operations between two threads

     Total time: 3.667 [sec]

       3.667667 usecs/op
         272652 ops/sec

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Link: http://lkml.kernel.org/r/20130917114256.GA31159@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ingo Molnar 2013-09-23 10:17:35 +02:00 committed by Arnaldo Carvalho de Melo
parent b52bc23414
commit a9faa0cab6
1 changed files with 86 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

115
tools/perf/bench/sched-pipe.c
View File

@ -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));
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];
}
}
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 {
for (i = 0; i < loops; i++) {
ret = write(pipe_1[1], &m, sizeof(int));
ret = read(pipe_2[0], &m, sizeof(int));
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));
}
gettimeofday(&stop, NULL);
timersub(&stop, &start, &diff);
if (pid) {
retpid = waitpid(pid, &wait_stat, 0);
assert((retpid == pid) && WIFEXITED(wait_stat));
} else {
exit(0);
}
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;