cregit-Linux how code gets into the kernel

Release 4.10 tools/perf/bench/sched-pipe.c

Directory: tools/perf/bench
/*
 *
 * sched-pipe.c
 *
 * pipe: Benchmark for pipe()
 *
 * 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 <subcmd/parse-options.h>
#include "../builtin.h"
#include "bench.h"

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/wait.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <linux/time64.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;

/* Use processes by default: */

static bool			threaded;


static const struct option options[] = {
	OPT_INTEGER('l', "loop",	&loops,		"Specify number of loops"),
	OPT_BOOLEAN('T', "threaded",	&threaded,	"Specify threads/process based task setup"),
	OPT_END()
};


static const char * const bench_sched_pipe_usage[] = {
	"perf bench sched pipe <options>",
	NULL
};


static void *worker_thread(void *__tdata) { 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; }

Contributors

PersonTokensPropCommitsCommitProp
ingo molnaringo molnar166100.00%1100.00%
Total166100.00%1100.00%


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? * discarding returned value of read(), write() * causes error in building environment for perf */ int __maybe_unused ret, wait_stat; pid_t pid, retpid __maybe_unused; argc = parse_options(argc, argv, options, bench_sched_pipe_usage, 0); BUG_ON(pipe(pipe_1)); BUG_ON(pipe(pipe_2)); gettimeofday(&start, NULL); 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 { 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); switch (bench_format) { case BENCH_FORMAT_DEFAULT: printf("# Executed %d pipe operations between two %s\n\n", loops, threaded ? "threads" : "processes"); result_usec = diff.tv_sec * USEC_PER_SEC; result_usec += diff.tv_usec; printf(" %14s: %lu.%03lu [sec]\n\n", "Total time", diff.tv_sec, (unsigned long) (diff.tv_usec / USEC_PER_MSEC)); printf(" %14lf usecs/op\n", (double)result_usec / (double)loops); printf(" %14d ops/sec\n", (int)((double)loops / ((double)result_usec / (double)USEC_PER_SEC))); break; case BENCH_FORMAT_SIMPLE: printf("%lu.%03lu\n", diff.tv_sec, (unsigned long) (diff.tv_usec / USEC_PER_MSEC)); break; default: /* reaching here is something disaster */ fprintf(stderr, "Unknown format:%d\n", bench_format); exit(1); break; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
hitoshi mitakehitoshi mitake30860.16%550.00%
ingo molnaringo molnar18335.74%110.00%
david s. millerdavid s. miller122.34%110.00%
irina tirdeairina tirdea50.98%220.00%
arnaldo carvalho de meloarnaldo carvalho de melo40.78%110.00%
Total512100.00%10100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
hitoshi mitakehitoshi mitake40049.08%541.67%
ingo molnaringo molnar38747.48%18.33%
david s. millerdavid s. miller121.47%18.33%
arnaldo carvalho de meloarnaldo carvalho de melo70.86%18.33%
irina tirdeairina tirdea50.61%216.67%
vineet guptavineet gupta30.37%18.33%
josh poimboeufjosh poimboeuf10.12%18.33%
Total815100.00%12100.00%
Directory: tools/perf/bench
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