hackbench is to test Linux scheduler. The original program is at
http://devresources.linux-foundation.org/craiger/hackbench/src/hackbench.c
Based on this multi-process version, a nice person created a multi-thread
version. Pls. see
http://www.bullopensource.org/posix/pi-futex/hackbench_pth.c
When I integrated them into my automation testing system, I found
a couple of issues and did some improvements.
1) Merge hackbench: I integrated hackbench_pth.c into hackbench and added a
new parameter which can be used to choose process mode or thread mode. The
default mode is process.
2) It runs too fast and ends in a couple of seconds. Sometimes it's too hard to
debug
the issues. On my ia64 Montecito machines, the result looks weird when comparing
process mode and thread mode.
I want a stable result and hope the testing could run for a stable longer time,
so I
might use performance tools to debug issues.
I added another new parameter,`loops`, which can be used to change variable
loops,
so more messages will be passed from writers to receivers. Parameter 'loops' is
equal to
100 by default.
For example on my 8-core x86_64:
[EMAIL PROTECTED] hackbench]$ uname -a
Linux lkp-st01-x8664 2.6.24-rc6 #1 SMP Fri Dec 21 08:32:31 CST 2007 x86_64
x86_64 x86_64 GNU/Linux
[EMAIL PROTECTED] hackbench]$ ./hackbench
Usage: hackbench [-pipe] <num groups> [process|thread] [loops]
[EMAIL PROTECTED] hackbench]$ ./hackbench 150 process 1000
Time: 151.533
[EMAIL PROTECTED] hackbench]$ ./hackbench 150 thread 1000
Time: 153.666
With the same new parameters, I did captured the SLUB issue discussed on LKML
recently.
3) hackbench_pth.c will fail on ia64 machine because pthread_attr_setstacksize
always
fails if the stack size is less than 196*1024. I moved this statement within a
__ia64__ check.
This new program could be compiled with command line:
#gcc -g -Wall -o hackbench hackbench.c -lpthread
Thank Ingo for his great comments!
-yanmin
---
/* Test groups of 20 processes spraying to 20 receivers */
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <sys/poll.h>
#define DATASIZE 100
static unsigned int loops = 100;
/*
* 0 means thread mode and others mean process (default)
*/
static unsigned int process_mode = 1;
static int use_pipes = 0;
struct sender_context {
unsigned int num_fds;
int ready_out;
int wakefd;
int out_fds[0];
};
struct receiver_context {
unsigned int num_packets;
int in_fds[2];
int ready_out;
int wakefd;
};
static void barf(const char *msg)
{
fprintf(stderr, "%s (error: %s)\n", msg, strerror(errno));
exit(1);
}
static void print_usage_exit()
{
printf("Usage: hackbench [-pipe] <num groups> [process|thread]
[loops]\n");
exit(1);
}
static void fdpair(int fds[2])
{
if (use_pipes) {
if (pipe(fds) == 0)
return;
} else {
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == 0)
return;
}
barf("Creating fdpair");
}
/* Block until we're ready to go */
static void ready(int ready_out, int wakefd)
{
char dummy;
struct pollfd pollfd = { .fd = wakefd, .events = POLLIN };
/* Tell them we're ready. */
if (write(ready_out, &dummy, 1) != 1)
barf("CLIENT: ready write");
/* Wait for "GO" signal */
if (poll(&pollfd, 1, -1) != 1)
barf("poll");
}
/* Sender sprays loops messages down each file descriptor */
static void *sender(struct sender_context *ctx)
{
char data[DATASIZE];
unsigned int i, j;
ready(ctx->ready_out, ctx->wakefd);
/* Now pump to every receiver. */
for (i = 0; i < loops; i++) {
for (j = 0; j < ctx->num_fds; j++) {
int ret, done = 0;
again:
ret = write(ctx->out_fds[j], data + done,
sizeof(data)-done);
if (ret < 0)
barf("SENDER: write");
done += ret;
if (done < sizeof(data))
goto again;
}
}
return NULL;
}
/* One receiver per fd */
static void *receiver(struct receiver_context* ctx)
{
unsigned int i;
if (process_mode)
close(ctx->in_fds[1]);
/* Wait for start... */
ready(ctx->ready_out, ctx->wakefd);
/* Receive them all */
for (i = 0; i < ctx->num_packets; i++) {
char data[DATASIZE];
int ret, done = 0;
again:
ret = read(ctx->in_fds[0], data + done, DATASIZE - done);
if (ret < 0)
barf("SERVER: read");
done += ret;
if (done < DATASIZE)
goto again;
}
return NULL;
}
pthread_t create_worker(void *ctx, void *(*func)(void *))
{
pthread_attr_t attr;
pthread_t childid;
int err;
if (process_mode) {
/* process mode */
/* Fork the receiver. */
switch (fork()) {
case -1: barf("fork()");
case 0:
(*func) (ctx);
exit(0);
}
return (pthread_t) 0;
}
if (pthread_attr_init(&attr) != 0)
barf("pthread_attr_init:");
#ifndef __ia64__
if (pthread_attr_setstacksize(&attr, (size_t)(16*1024)) != 0)
barf("pthread_attr_setstacksize");
#endif
if ((err=pthread_create(&childid, &attr, func, ctx)) != 0) {
fprintf(stderr, "pthread_create failed: %s (%d)\n",
strerror(err), err);
exit(-1);
}
return (childid);
}
void reap_worker(pthread_t id)
{
int status;
if (process_mode) {
/* process mode */
wait(&status);
if (!WIFEXITED(status))
exit(1);
} else
pthread_join(id, (void**)&status);
}
/* One group of senders and receivers */
static unsigned int group(pthread_t *pth,
unsigned int num_fds,
int ready_out,
int wakefd)
{
unsigned int i;
struct sender_context* snd_ctx = malloc (sizeof(struct sender_context)
+num_fds*sizeof(int));
for (i = 0; i < num_fds; i++) {
int fds[2];
struct receiver_context* ctx = malloc (sizeof(*ctx));
if (!ctx)
barf("malloc()");
/* Create the pipe between client and server */
fdpair(fds);
ctx->num_packets = num_fds*loops;
ctx->in_fds[0] = fds[0];
ctx->in_fds[1] = fds[1];
ctx->ready_out = ready_out;
ctx->wakefd = wakefd;
pth[i] = create_worker(ctx, (void *)(void *)receiver);
snd_ctx->out_fds[i] = fds[1];
if (process_mode)
close(fds[0]);
}
/* Now we have all the fds, fork the senders */
for (i = 0; i < num_fds; i++) {
snd_ctx->ready_out = ready_out;
snd_ctx->wakefd = wakefd;
snd_ctx->num_fds = num_fds;
pth[num_fds+i] = create_worker(snd_ctx, (void *)(void *)sender);
}
/* Close the fds we have left */
if (process_mode)
for (i = 0; i < num_fds; i++)
close(snd_ctx->out_fds[i]);
/* Return number of children to reap */
return num_fds * 2;
}
int main(int argc, char *argv[])
{
unsigned int i, num_groups, total_children;
struct timeval start, stop, diff;
unsigned int num_fds = 20;
int readyfds[2], wakefds[2];
char dummy;
pthread_t *pth_tab;
if (argv[1] && strcmp(argv[1], "-pipe") == 0) {
use_pipes = 1;
argc--;
argv++;
}
if (argc < 2 || (num_groups = atoi(argv[1])) == 0)
print_usage_exit();
if (argc > 2) {
if ( !strcmp(argv[2], "process") )
process_mode = 1;
else if ( !strcmp(argv[2], "thread") )
process_mode = 0;
else
print_usage_exit();
}
if (argc > 3)
loops = atoi(argv[3]);
pth_tab = malloc(num_fds * 2 * num_groups * sizeof(pthread_t));
if (!pth_tab)
barf("main:malloc()");
fdpair(readyfds);
fdpair(wakefds);
total_children = 0;
for (i = 0; i < num_groups; i++)
total_children += group(pth_tab+total_children, num_fds,
readyfds[1], wakefds[0]);
/* Wait for everyone to be ready */
for (i = 0; i < total_children; i++)
if (read(readyfds[0], &dummy, 1) != 1)
barf("Reading for readyfds");
gettimeofday(&start, NULL);
/* Kick them off */
if (write(wakefds[1], &dummy, 1) != 1)
barf("Writing to start them");
/* Reap them all */
for (i = 0; i < total_children; i++)
reap_worker(pth_tab[i]);
gettimeofday(&stop, NULL);
/* Print time... */
timersub(&stop, &start, &diff);
printf("Time: %lu.%03lu\n", diff.tv_sec, diff.tv_usec/1000);
exit(0);
}
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