xref: /onnv-gate/usr/src/cmd/filebench/common/procflow.c (revision 6084:d5f45b4dae7e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 #include <signal.h>
29 #include <fcntl.h>
30 #include <sys/stat.h>
31 #include <sys/wait.h>
32 
33 #include "procflow.h"
34 #include "filebench.h"
35 #include "flowop.h"
36 #include "ipc.h"
37 
38 /* pid and procflow pointer for this process */
39 pid_t my_pid;
40 procflow_t *my_procflow = NULL;
41 
42 static procflow_t *procflow_define_common(procflow_t **list, char *name,
43     procflow_t *inherit, int instance);
44 
45 #ifdef USE_PROCESS_MODEL
46 
47 static enum create_n_wait {
48 	CNW_DONE,
49 	CNW_ERROR
50 } cnw_wait;
51 
52 static pthread_cond_t procflow_procs_created;
53 
54 #endif	/* USE_PROCESS_MODEL */
55 
56 
57 /*
58  * Procflows are filebench entities which manage processes. Each
59  * worker procflow spawns a separate filebench process, with attributes
60  * inherited from a FLOW_MASTER procflow created during f model language
61  * parsing. This section contains routines to define, create, control,
62  * and delete procflows.
63  *
64  * Each process defined in the f model creates a FLOW_MASTER
65  * procflow which encapsulates the defined attributes, and threads of
66  * the f process, including the number of instances to create. At
67  * runtime, a worker procflow instance with an associated filebench
68  * process is created, which runs until told to quite by the original
69  * filebench process or is specifically deleted.
70  */
71 
72 
73 /*
74  * Prints a summary of the syntax for setting procflow parameters.
75  */
76 void
77 procflow_usage(void)
78 {
79 	(void) fprintf(stderr,
80 	    "define process name=<name>[,instances=<count>]\n");
81 	(void) fprintf(stderr, "{\n");
82 	(void) fprintf(stderr, "  thread ...\n");
83 	(void) fprintf(stderr, "  thread ...\n");
84 	(void) fprintf(stderr, "  thread ...\n");
85 	(void) fprintf(stderr, "}\n");
86 	(void) fprintf(stderr, "\n");
87 	(void) fprintf(stderr, "\n");
88 }
89 
90 /*
91  * If filebench has been compiled to support multiple processes
92  * (USE_PROCESS_MODEL defined), this routine forks a child
93  * process and uses either system() or exec() to start up a new
94  * instance of filebench, passing it the procflow name, instance
95  * number and shared memory region address.
96  * If USE_PROCESS_MODEL is NOT defined, then the routine
97  * just creates a child thread which begins executing
98  * threadflow_init() for the specified procflow.
99  */
100 static int
101 procflow_createproc(procflow_t *procflow)
102 {
103 	char instance[128];
104 	char shmaddr[128];
105 	char procname[128];
106 	pid_t pid;
107 
108 #ifdef USE_PROCESS_MODEL
109 
110 	(void) snprintf(instance, sizeof (instance), "%d",
111 	    procflow->pf_instance);
112 	(void) snprintf(procname, sizeof (procname), "%s", procflow->pf_name);
113 #if defined(_LP64) || (__WORDSIZE == 64)
114 	(void) snprintf(shmaddr, sizeof (shmaddr), "%llx", filebench_shm);
115 #else
116 	(void) snprintf(shmaddr, sizeof (shmaddr), "%x", filebench_shm);
117 #endif
118 	filebench_log(LOG_DEBUG_IMPL, "creating process %s",
119 	    procflow->pf_name);
120 
121 	procflow->pf_running = 0;
122 
123 #ifdef HAVE_FORK1
124 	if ((pid = fork1()) < 0) {
125 		filebench_log(LOG_ERROR,
126 		    "procflow_createproc fork failed: %s",
127 		    strerror(errno));
128 		return (-1);
129 	}
130 #else
131 	if ((pid = fork()) < 0) {
132 		filebench_log(LOG_ERROR,
133 		    "procflow_createproc fork failed: %s",
134 		    strerror(errno));
135 		return (-1);
136 	}
137 #endif /* HAVE_FORK1 */
138 
139 	/* if child, start up new copy of filebench */
140 	if (pid == 0) {
141 #ifdef USE_SYSTEM
142 		char syscmd[1024];
143 #endif
144 
145 		(void) sigignore(SIGINT);
146 		filebench_log(LOG_DEBUG_SCRIPT,
147 		    "Starting %s-%d", procflow->pf_name,
148 		    procflow->pf_instance);
149 		/* Child */
150 
151 #ifdef USE_SYSTEM
152 		(void) snprintf(syscmd, sizeof (syscmd), "%s -a %s -i %s -s %s",
153 		    execname,
154 		    procname,
155 		    instance,
156 		    shmaddr);
157 		if (system(syscmd) < 0) {
158 			filebench_log(LOG_ERROR,
159 			    "procflow exec proc failed: %s",
160 			    strerror(errno));
161 			filebench_shutdown(1);
162 		}
163 
164 #else
165 		if (execl(execname, procname, "-a", procname, "-i",
166 		    instance, "-s", shmaddr, "-m", shmpath, NULL) < 0) {
167 			filebench_log(LOG_ERROR,
168 			    "procflow exec proc failed: %s",
169 			    strerror(errno));
170 			filebench_shutdown(1);
171 		}
172 #endif
173 		exit(1);
174 	} else {
175 		/* if parent, save pid and return */
176 		procflow->pf_pid = pid;
177 	}
178 #else
179 	procflow->pf_running = 1;
180 	if (pthread_create(&procflow->pf_tid, NULL,
181 	    (void *(*)(void*))threadflow_init, procflow) != 0) {
182 		filebench_log(LOG_ERROR, "proc-thread create failed");
183 		procflow->pf_running = 0;
184 	}
185 #endif
186 	filebench_log(LOG_DEBUG_IMPL, "procflow_createproc created pid %d",
187 	    pid);
188 
189 	return (0);
190 }
191 
192 /*
193  * Find a procflow of name "name" and instance "instance" on the
194  * master procflow list, filebench_shm->proclist. Locks the list
195  * and scans through it searching for a procflow with matching
196  * name and instance number. If found returns a pointer to the
197  * procflow, otherwise returns NULL.
198  */
199 static procflow_t *
200 procflow_find(char *name, int instance)
201 {
202 	procflow_t *procflow = filebench_shm->proclist;
203 
204 	filebench_log(LOG_DEBUG_IMPL, "Find: (%s-%d) proclist = %zx",
205 	    name, instance, procflow);
206 
207 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
208 
209 	while (procflow) {
210 		filebench_log(LOG_DEBUG_IMPL, "Find: (%s-%d) == (%s-%d)",
211 		    name, instance,
212 		    procflow->pf_name,
213 		    procflow->pf_instance);
214 		if ((strcmp(name, procflow->pf_name) == 0) &&
215 		    (instance == procflow->pf_instance)) {
216 
217 			(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
218 
219 			return (procflow);
220 		}
221 		procflow = procflow->pf_next;
222 	}
223 
224 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
225 
226 	return (NULL);
227 }
228 
229 static int
230 procflow_create_all_procs(void)
231 {
232 	procflow_t *procflow = filebench_shm->proclist;
233 	int	ret = 0;
234 
235 	while (procflow) {
236 		int i;
237 
238 		filebench_log(LOG_INFO, "Starting %lld %s instances",
239 		    *(procflow->pf_instances), procflow->pf_name);
240 
241 		/* Create instances of procflow */
242 		for (i = 0; (i < *procflow->pf_instances) && (ret == 0); i++) {
243 			procflow_t *newproc;
244 
245 			/* Create processes */
246 			newproc =
247 			    procflow_define_common(&filebench_shm->proclist,
248 			    procflow->pf_name, procflow, i + 1);
249 			if (newproc == NULL)
250 				ret = -1;
251 			else
252 				ret = procflow_createproc(newproc);
253 		}
254 
255 		if (ret != 0)
256 			break;
257 
258 		procflow = procflow->pf_next;
259 	}
260 
261 	return (ret);
262 }
263 
264 #ifdef USE_PROCESS_MODEL
265 /*
266  * Used to start up threads on a child process, when filebench is
267  * compiled to support multiple processes. Uses the name string
268  * and instance number passed to the child to find the previously
269  * created procflow entity. Then uses nice() to reduce the
270  * process' priority by at least 10. A call is then made to
271  * threadflow_init() which creates and runs the process' threads
272  * and flowops to completion. When threadflow_init() returns,
273  * a call to exit() terminates the child process.
274  */
275 int
276 procflow_exec(char *name, int instance)
277 {
278 	procflow_t *procflow;
279 	int proc_nice;
280 #ifdef HAVE_SETRLIMIT
281 	struct rlimit rlp;
282 #endif
283 	int ret;
284 
285 	filebench_log(LOG_DEBUG_IMPL,
286 	    "procflow_execproc %s-%d",
287 	    name, instance);
288 
289 	if ((procflow = procflow_find(name, instance)) == NULL) {
290 		filebench_log(LOG_ERROR,
291 		    "procflow_exec could not find %s-%d",
292 		    name, instance);
293 		return (-1);
294 	}
295 
296 	/* set the slave process' procflow pointer */
297 	my_procflow = procflow;
298 
299 	/* set its pid from value stored by main() */
300 	procflow->pf_pid = my_pid;
301 
302 	filebench_log(LOG_DEBUG_IMPL,
303 	    "Started up %s pid %d", procflow->pf_name, my_pid);
304 
305 	filebench_log(LOG_DEBUG_IMPL,
306 	    "nice = %llx", procflow->pf_nice);
307 
308 	proc_nice = *procflow->pf_nice;
309 	filebench_log(LOG_DEBUG_IMPL, "Setting pri of %s-%d to %d",
310 	    name, instance, nice(proc_nice + 10));
311 
312 	procflow->pf_running = 1;
313 
314 #ifdef HAVE_SETRLIMIT
315 	/* Get resource limits */
316 	(void) getrlimit(RLIMIT_NOFILE, &rlp);
317 	filebench_log(LOG_DEBUG_SCRIPT, "%d file descriptors", rlp.rlim_cur);
318 #endif
319 
320 	if ((ret = threadflow_init(procflow)) != FILEBENCH_OK) {
321 		if (ret < 0) {
322 			filebench_log(LOG_ERROR,
323 			    "Failed to start threads for %s pid %d",
324 			    procflow->pf_name, my_pid);
325 		}
326 	} else {
327 		filebench_log(LOG_DEBUG_IMPL,
328 		    "procflow_createproc exiting...");
329 	}
330 
331 	procflow->pf_running = 0;
332 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
333 	filebench_shm->shm_running --;
334 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
335 
336 	return (ret);
337 }
338 
339 
340 /*
341  * A special thread from which worker (child) processes are created, and
342  * which then waits for worker processes to die. If they die unexpectedly,
343  * that is not a simple exit(0), then report an error and terminate the
344  * run.
345  */
346 /* ARGSUSED */
347 static void *
348 procflow_createnwait(void *nothing)
349 {
350 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
351 
352 	if (procflow_create_all_procs() == 0)
353 		cnw_wait = CNW_DONE;
354 	else
355 		cnw_wait = CNW_ERROR;
356 
357 	if (pthread_cond_signal(&procflow_procs_created) != 0)
358 		exit(1);
359 
360 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
361 
362 	/* CONSTCOND */
363 	while (1) {
364 		siginfo_t status;
365 
366 		/* wait for any child process to exit */
367 		if (waitid(P_ALL, 0, &status, WEXITED) != 0)
368 			pthread_exit(0);
369 
370 		/* if normal shutdown in progress, just quit */
371 		if (filebench_shm->f_abort)
372 			pthread_exit(0);
373 
374 		if (status.si_code == CLD_EXITED) {
375 			/* A process called exit(); check returned status */
376 			if (status.si_status != 0) {
377 				filebench_log(LOG_ERROR,
378 				    "Unexpected Process termination; exiting",
379 				    status.si_status);
380 				filebench_shutdown(1);
381 			}
382 		} else {
383 			/* A process quit because of some fatal error */
384 			filebench_log(LOG_ERROR,
385 			    "Unexpected Process termination Code %d, Errno %d",
386 			    status.si_code, status.si_errno);
387 			filebench_shutdown(1);
388 		}
389 
390 		/* nothing running, exit */
391 		if (filebench_shm->shm_running == 0) {
392 			filebench_shm->f_abort = FILEBENCH_ABORT_RSRC;
393 			pthread_exit(0);
394 		}
395 	}
396 	/* NOTREACHED */
397 	return (NULL);
398 }
399 #endif	/* USE_PROCESS_MODEL */
400 
401 /*
402  * Iterates through proclist, the master list of procflows,
403  * creating the number of instances of each procflow specified
404  * by its pf_instance attribute. Returns 0 on success, or -1
405  * times the number of procflow instances that were not
406  * successfully created.
407  */
408 int
409 procflow_init(void)
410 {
411 	procflow_t *procflow = filebench_shm->proclist;
412 	pthread_t tid;
413 	int ret = 0;
414 
415 	filebench_log(LOG_DEBUG_IMPL,
416 	    "procflow_init %s, %lld",
417 	    procflow->pf_name, *(procflow->pf_instances));
418 
419 #ifdef USE_PROCESS_MODEL
420 	if ((ret = pthread_cond_init(&procflow_procs_created, NULL)) != 0)
421 		return (ret);
422 
423 	if ((pthread_create(&tid, NULL, procflow_createnwait, NULL)) != 0)
424 		return (ret);
425 
426 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
427 
428 	if ((ret = pthread_cond_wait(&procflow_procs_created,
429 	    &filebench_shm->procflow_lock)) != 0)
430 		return (ret);
431 
432 	if (cnw_wait == CNW_ERROR)
433 		ret = -1;
434 
435 #else /* USE_PROCESS_MODEL */
436 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
437 
438 	ret = procflow_create_all_procs();
439 #endif /* USE_PROCESS_MODEL */
440 
441 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
442 
443 	return (ret);
444 }
445 
446 #ifdef USE_PROCESS_MODEL
447 /*
448  * Waits for child processes to finish and returns their exit
449  * status. Used by procflow_delete() when the process model is
450  * enabled to wait for a deleted process to exit.
451  */
452 static void
453 procflow_wait(pid_t pid)
454 {
455 	pid_t wpid;
456 	int stat;
457 
458 	(void) waitpid(pid, &stat, 0);
459 	while ((wpid = waitpid(getpid() * -1, &stat, WNOHANG)) > 0)
460 		filebench_log(LOG_DEBUG_IMPL, "Waited for pid %lld", wpid);
461 }
462 #endif
463 
464 /*
465  * Deletes the designated procflow and all its threadflows except
466  * for FLOW_MASTER ones. Waits 10 seconds if the procflow is still
467  * running, then kills the associated process. Finally it frees the
468  * procflow entity. filebench_shm->procflow_lock must be held on entry.
469  *
470  * If the designated procflow is not found on the list it returns -1 and
471  * the procflow is not deleted. Otherwise it returns 0.
472  */
473 static int
474 procflow_delete(procflow_t *procflow, int wait_cnt)
475 {
476 	procflow_t *entry;
477 
478 	threadflow_delete_all(&procflow->pf_threads, wait_cnt);
479 
480 	filebench_log(LOG_DEBUG_SCRIPT,
481 	    "Deleted proc: (%s-%d) pid %d",
482 	    procflow->pf_name,
483 	    procflow->pf_instance,
484 	    procflow->pf_pid);
485 
486 	while (procflow->pf_running == 1) {
487 		filebench_log(LOG_DEBUG_SCRIPT,
488 		    "Waiting for process %s-%d %d",
489 		    procflow->pf_name,
490 		    procflow->pf_instance,
491 		    procflow->pf_pid);
492 
493 		if (wait_cnt) {
494 			(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
495 			(void) sleep(1);
496 			(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
497 			wait_cnt--;
498 			continue;
499 		}
500 #ifdef USE_PROCESS_MODEL
501 		(void) kill(procflow->pf_pid, SIGKILL);
502 		filebench_log(LOG_DEBUG_SCRIPT,
503 		    "Had to kill process %s-%d %d!",
504 		    procflow->pf_name,
505 		    procflow->pf_instance,
506 		    procflow->pf_pid);
507 		procflow->pf_running = 0;
508 #endif
509 	}
510 
511 #ifdef USE_PROCESS_MODEL
512 	procflow_wait(procflow->pf_pid);
513 #endif
514 	/* remove entry from proclist */
515 	entry = filebench_shm->proclist;
516 
517 	/* unlink procflow entity from proclist */
518 	if (entry == procflow) {
519 		/* at head of list */
520 		filebench_shm->proclist = procflow->pf_next;
521 	} else {
522 		/* search list for procflow */
523 		while (entry && entry->pf_next != procflow)
524 			entry = entry->pf_next;
525 
526 		/* if entity found, unlink it */
527 		if (entry == NULL)
528 			return (-1);
529 		else
530 			entry->pf_next = procflow->pf_next;
531 	}
532 
533 	/* free up the procflow entity */
534 	ipc_free(FILEBENCH_PROCFLOW, (char *)procflow);
535 	return (0);
536 }
537 
538 
539 /*
540  * Waits till all threadflows are started, or a timeout occurs.
541  * Checks through the list of procflows, waiting up to 30
542  * seconds for each one to set its pf_running flag to 1. If not
543  * set after 30 seconds, continues on to the next procflow
544  * anyway after logging the fact. Once pf_running is set
545  * to 1 for a given procflow or the timeout is reached,
546  * threadflow_allstarted() is called to start the threads.
547  * Returns 0 (OK), unless filebench_shm->f_abort is signaled,
548  * in which case it returns -1.
549  */
550 int
551 procflow_allstarted()
552 {
553 	procflow_t *procflow = filebench_shm->proclist;
554 	int running_procs = 0;
555 	int ret = 0;
556 
557 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
558 
559 	(void) sleep(1);
560 
561 	while (procflow) {
562 		int waits;
563 
564 		if (procflow->pf_instance &&
565 		    (procflow->pf_instance == FLOW_MASTER)) {
566 			procflow = procflow->pf_next;
567 			continue;
568 		}
569 
570 		waits = 10;
571 		while (waits && procflow->pf_running == 0) {
572 			(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
573 			if (filebench_shm->f_abort == 1)
574 				return (-1);
575 
576 			if (waits < 3)
577 				filebench_log(LOG_INFO,
578 				    "Waiting for process %s-%d %d",
579 				    procflow->pf_name,
580 				    procflow->pf_instance,
581 				    procflow->pf_pid);
582 
583 			(void) sleep(3);
584 			waits--;
585 			(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
586 		}
587 
588 		if (waits == 0)
589 			filebench_log(LOG_INFO,
590 			    "Failed to start process %s-%d",
591 			    procflow->pf_name,
592 			    procflow->pf_instance);
593 
594 		running_procs++;
595 		threadflow_allstarted(procflow->pf_pid, procflow->pf_threads);
596 
597 		procflow = procflow->pf_next;
598 	}
599 	filebench_shm->shm_running = running_procs;
600 
601 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
602 
603 
604 	return (ret);
605 }
606 
607 
608 /*
609  * Sets the f_abort flag and clears the running count to stop
610  * all the flowop execution threads from running. Iterates
611  * through the procflow list and deletes all procflows except
612  * for the FLOW_MASTER procflow. Resets the f_abort flag when
613  * finished.
614  */
615 void
616 procflow_shutdown(void)
617 {
618 	procflow_t *procflow = filebench_shm->proclist;
619 	int wait_cnt;
620 
621 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
622 	filebench_shm->shm_running = 0;
623 	filebench_shm->f_abort = 1;
624 	wait_cnt = SHUTDOWN_WAIT_SECONDS;
625 
626 	while (procflow) {
627 		if (procflow->pf_instance &&
628 		    (procflow->pf_instance == FLOW_MASTER)) {
629 			procflow = procflow->pf_next;
630 			continue;
631 		}
632 		filebench_log(LOG_DEBUG_IMPL, "Deleting process %s-%d %d",
633 		    procflow->pf_name,
634 		    procflow->pf_instance,
635 		    procflow->pf_pid);
636 		(void) procflow_delete(procflow, wait_cnt);
637 		procflow = procflow->pf_next;
638 		/* grow more impatient */
639 		if (wait_cnt)
640 			wait_cnt--;
641 	}
642 
643 	filebench_shm->f_abort = 0;
644 
645 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
646 }
647 
648 
649 /*
650  * Create an in-memory process object. Allocates a procflow
651  * entity, initialized from the "inherit" procflow if supplied.
652  * The name and instance number are set from the supplied name
653  * and instance number and the procflow is added to the head of
654  * the master procflow list. Returns pointer to the allocated
655  * procflow, or NULL if a name isn't supplied or the procflow
656  * entity cannot be allocated.
657  *
658  * The calling routine must hold the filebench_shm->procflow_lock.
659  */
660 static procflow_t *
661 procflow_define_common(procflow_t **list, char *name,
662     procflow_t *inherit, int instance)
663 {
664 	procflow_t *procflow;
665 
666 	if (name == NULL)
667 		return (NULL);
668 
669 	procflow = (procflow_t *)ipc_malloc(FILEBENCH_PROCFLOW);
670 
671 	if (procflow == NULL)
672 		return (NULL);
673 
674 	if (inherit)
675 		(void) memcpy(procflow, inherit, sizeof (procflow_t));
676 	else
677 		(void) memset(procflow, 0, sizeof (procflow_t));
678 
679 	procflow->pf_instance = instance;
680 	(void) strcpy(procflow->pf_name, name);
681 
682 	filebench_log(LOG_DEBUG_IMPL, "defining process %s-%d", name, instance);
683 
684 	filebench_log(LOG_DEBUG_IMPL, "process %s-%d proclist %zx",
685 	    name, instance, filebench_shm->proclist);
686 	/* Add procflow to list, lock is being held already */
687 	if (*list == NULL) {
688 		*list = procflow;
689 		procflow->pf_next = NULL;
690 	} else {
691 		procflow->pf_next = *list;
692 		*list = procflow;
693 	}
694 	filebench_log(LOG_DEBUG_IMPL, "process %s-%d proclist %zx",
695 	    name, instance, filebench_shm->proclist);
696 
697 	return (procflow);
698 }
699 
700 /*
701  * Create an in-memory process object as described by the syntax.
702  * Acquires the filebench_shm->procflow_lock and calls
703  * procflow_define_common() to create and initialize a
704  * FLOW_MASTER procflow entity from the optional "inherit"
705  * procflow with the given name and configured for "instances"
706  * number of worker procflows. Currently only called from
707  * parser_proc_define().
708  */
709 procflow_t *
710 procflow_define(char *name, procflow_t *inherit, var_integer_t instances)
711 {
712 	procflow_t *procflow;
713 
714 	(void) ipc_mutex_lock(&filebench_shm->procflow_lock);
715 
716 	procflow = procflow_define_common(&filebench_shm->proclist,
717 	    name, inherit, FLOW_MASTER);
718 	procflow->pf_instances = instances;
719 
720 	(void) ipc_mutex_unlock(&filebench_shm->procflow_lock);
721 
722 	return (procflow);
723 }
724