[mirror_frr.git] / lib / workqueue.c

/* 
 * Quagga Work Queue Support.
 *
 * Copyright (C) 2005 Sun Microsystems, Inc.
 *
 * This file is part of GNU Zebra.
 *
 * Quagga is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * Quagga is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Quagga; see the file COPYING.  If not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.  
 */

#include <lib/zebra.h>
#include "thread.h"
#include "memory.h"
#include "workqueue.h"
#include "linklist.h"
#include "command.h"
#include "log.h"

/* master list of work_queues */
static struct list work_queues;

#define WORK_QUEUE_MIN_GRANULARITY 1

static struct work_queue_item *
work_queue_item_new (struct work_queue *wq)
{
  struct work_queue_item *item;
  assert (wq);

  item = XCALLOC (MTYPE_WORK_QUEUE_ITEM, 
                  sizeof (struct work_queue_item));
  
  return item;
}

static void
work_queue_item_free (struct work_queue_item *item)
{
  XFREE (MTYPE_WORK_QUEUE_ITEM, item);
  return;
}

/* create new work queue */
struct work_queue *
work_queue_new (struct thread_master *m, const char *queue_name)
{
  struct work_queue *new;
  
  new = XCALLOC (MTYPE_WORK_QUEUE, sizeof (struct work_queue));

  if (new == NULL)
    return new;
  
  new->name = XSTRDUP (MTYPE_WORK_QUEUE_NAME, queue_name);
  new->master = m;
  SET_FLAG (new->flags, WQ_UNPLUGGED);
  
  if ( (new->items = list_new ()) == NULL)
    {
      XFREE (MTYPE_WORK_QUEUE_NAME, new->name);
      XFREE (MTYPE_WORK_QUEUE, new);
      
      return NULL;
    }
  
  new->items->del = (void (*)(void *)) work_queue_item_free;  
  
  listnode_add (&work_queues, new);
  
  new->cycles.granularity = WORK_QUEUE_MIN_GRANULARITY;

  /* Default values, can be overriden by caller */
  new->spec.hold = WORK_QUEUE_DEFAULT_HOLD;
  new->spec.yield = THREAD_YIELD_TIME_SLOT;
    
  return new;
}

void
work_queue_free (struct work_queue *wq)
{
  if (wq->thread != NULL)
    thread_cancel(wq->thread);
  
  /* list_delete frees items via callback */
  list_delete (wq->items);
  listnode_delete (&work_queues, wq);
  
  XFREE (MTYPE_WORK_QUEUE_NAME, wq->name);
  XFREE (MTYPE_WORK_QUEUE, wq);
  return;
}

static int
work_queue_schedule (struct work_queue *wq, unsigned int delay)
{
  /* if appropriate, schedule work queue thread */
  if ( CHECK_FLAG (wq->flags, WQ_UNPLUGGED)
       && (wq->thread == NULL)
       && (listcount (wq->items) > 0) )
    {
      wq->thread = thread_add_background (wq->master, work_queue_run, 
                                          wq, delay);
      /* set thread yield time, if needed */
      if (wq->thread && wq->spec.yield != THREAD_YIELD_TIME_SLOT)
        thread_set_yield_time (wq->thread, wq->spec.yield);
      return 1;
    }
  else
    return 0;
}
  
void
work_queue_add (struct work_queue *wq, void *data)
{
  struct work_queue_item *item;
  
  assert (wq);

  if (!(item = work_queue_item_new (wq)))
    {
      zlog_err ("%s: unable to get new queue item", __func__);
      return;
    }
  
  item->data = data;
  listnode_add (wq->items, item);
  
  work_queue_schedule (wq, wq->spec.hold);
  
  return;
}

static void
work_queue_item_remove (struct work_queue *wq, struct listnode *ln)
{
  struct work_queue_item *item = listgetdata (ln);

  assert (item && item->data);

  /* call private data deletion callback if needed */  
  if (wq->spec.del_item_data)
    wq->spec.del_item_data (wq, item->data);

  list_delete_node (wq->items, ln);
  work_queue_item_free (item);
  
  return;
}

static void
work_queue_item_requeue (struct work_queue *wq, struct listnode *ln)
{
  LISTNODE_DETACH (wq->items, ln);
  LISTNODE_ATTACH (wq->items, ln); /* attach to end of list */
}

DEFUN(show_work_queues,
      show_work_queues_cmd,
      "show work-queues",
      SHOW_STR
      "Work Queue information\n")
{
  struct listnode *node;
  struct work_queue *wq;
  
  vty_out (vty, 
           "%c %8s %5s %8s %8s %21s%s",
           ' ', "List","(ms) ","Q. Runs","Yields","Cycle Counts   ",
           VTY_NEWLINE);
  vty_out (vty,
           "%c %8s %5s %8s %8s %7s %6s %8s %6s %s%s",
           'P',
           "Items",
           "Hold",
           "Total","Total",
           "Best","Gran.","Total","Avg.",
           "Name", 
           VTY_NEWLINE);
 
  for (ALL_LIST_ELEMENTS_RO ((&work_queues), node, wq))
    {
      vty_out (vty,"%c %8d %5d %8ld %8ld %7d %6d %8ld %6u %s%s",
               (CHECK_FLAG (wq->flags, WQ_UNPLUGGED) ? ' ' : 'P'),
               listcount (wq->items),
               wq->spec.hold,
               wq->runs, wq->yields,
               wq->cycles.best, wq->cycles.granularity, wq->cycles.total,
                 (wq->runs) ? 
                   (unsigned int) (wq->cycles.total / wq->runs) : 0,
               wq->name,
               VTY_NEWLINE);
    }
    
  return CMD_SUCCESS;
}

/* 'plug' a queue: Stop it from being scheduled,
 * ie: prevent the queue from draining.
 */
void
work_queue_plug (struct work_queue *wq)
{
  if (wq->thread)
    thread_cancel (wq->thread);
  
  wq->thread = NULL;
  
  UNSET_FLAG (wq->flags, WQ_UNPLUGGED);
}

/* unplug queue, schedule it again, if appropriate
 * Ie: Allow the queue to be drained again
 */
void
work_queue_unplug (struct work_queue *wq)
{
  SET_FLAG (wq->flags, WQ_UNPLUGGED);

  /* if thread isnt already waiting, add one */
  work_queue_schedule (wq, wq->spec.hold);
}

/* timer thread to process a work queue
 * will reschedule itself if required,
 * otherwise work_queue_item_add 
 */
int
work_queue_run (struct thread *thread)
{
  struct work_queue *wq;
  struct work_queue_item *item;
  wq_item_status ret;
  unsigned int cycles = 0;
  struct listnode *node, *nnode;
  char yielded = 0;

  wq = THREAD_ARG (thread);
  wq->thread = NULL;

  assert (wq && wq->items);

  /* calculate cycle granularity:
   * list iteration == 1 run
   * listnode processing == 1 cycle
   * granularity == # cycles between checks whether we should yield.
   *
   * granularity should be > 0, and can increase slowly after each run to
   * provide some hysteris, but not past cycles.best or 2*cycles.
   *
   * Best: starts low, can only increase
   *
   * Granularity: starts at WORK_QUEUE_MIN_GRANULARITY, can be decreased 
   *              if we run to end of time slot, can increase otherwise 
   *              by a small factor.
   *
   * We could use just the average and save some work, however we want to be
   * able to adjust quickly to CPU pressure. Average wont shift much if
   * daemon has been running a long time.
   */
   if (wq->cycles.granularity == 0)
     wq->cycles.granularity = WORK_QUEUE_MIN_GRANULARITY;

  for (ALL_LIST_ELEMENTS (wq->items, node, nnode, item))
  {
    assert (item && item->data);
    
    /* dont run items which are past their allowed retries */
    if (item->ran > wq->spec.max_retries)
      {
        /* run error handler, if any */
	if (wq->spec.errorfunc)
	  wq->spec.errorfunc (wq, item->data);
	work_queue_item_remove (wq, node);
	continue;
      }

    /* run and take care of items that want to be retried immediately */
    do
      {
        ret = wq->spec.workfunc (wq, item->data);
        item->ran++;
      }
    while ((ret == WQ_RETRY_NOW) 
           && (item->ran < wq->spec.max_retries));

    switch (ret)
      {
      case WQ_QUEUE_BLOCKED:
        {
          /* decrement item->ran again, cause this isn't an item
           * specific error, and fall through to WQ_RETRY_LATER
           */
          item->ran--;
        }
      case WQ_RETRY_LATER:
	{
	  goto stats;
	}
      case WQ_REQUEUE:
	{
	  item->ran--;
	  work_queue_item_requeue (wq, node);
      /* If a single node is being used with a meta-queue (e.g., zebra),
       * update the next node as we don't want to exit the thread and
       * reschedule it after every node. By definition, WQ_REQUEUE is
       * meant to continue the processing; the yield logic will kick in
       * to terminate the thread when time has exceeded.
       */
      if (nnode == NULL)
        nnode = node;
	  break;
	}
      case WQ_RETRY_NOW:
        /* a RETRY_NOW that gets here has exceeded max_tries, same as ERROR */
      case WQ_ERROR:
	{
	  if (wq->spec.errorfunc)
	    wq->spec.errorfunc (wq, item);
	}
	/* fall through here is deliberate */
      case WQ_SUCCESS:
      default:
	{
	  work_queue_item_remove (wq, node);
	  break;
	}
      }

    /* completed cycle */
    cycles++;

    /* test if we should yield */
    if ( !(cycles % wq->cycles.granularity) 
        && thread_should_yield (thread))
      {
        yielded = 1;
        goto stats;
      }
  }

stats:

#define WQ_HYSTERESIS_FACTOR 4

  /* we yielded, check whether granularity should be reduced */
  if (yielded && (cycles < wq->cycles.granularity))
    {
      wq->cycles.granularity = ((cycles > 0) ? cycles
                                             : WORK_QUEUE_MIN_GRANULARITY);
    }
  /* otherwise, should granularity increase? */
  else if (cycles >= (wq->cycles.granularity))
    {
      if (cycles > wq->cycles.best)
        wq->cycles.best = cycles;

      /* along with yielded check, provides hysteresis for granularity */
      if (cycles > (wq->cycles.granularity * WQ_HYSTERESIS_FACTOR
                                           * WQ_HYSTERESIS_FACTOR))
        wq->cycles.granularity *= WQ_HYSTERESIS_FACTOR; /* quick ramp-up */
      else if (cycles > (wq->cycles.granularity * WQ_HYSTERESIS_FACTOR))
        wq->cycles.granularity += WQ_HYSTERESIS_FACTOR;
    }
#undef WQ_HYSTERIS_FACTOR
  
  wq->runs++;
  wq->cycles.total += cycles;
  if (yielded)
    wq->yields++;

#if 0
  printf ("%s: cycles %d, new: best %d, worst %d\n",
            __func__, cycles, wq->cycles.best, wq->cycles.granularity);
#endif
  
  /* Is the queue done yet? If it is, call the completion callback. */
  if (listcount (wq->items) > 0)
    work_queue_schedule (wq, 0);
  else if (wq->spec.completion_func)
    wq->spec.completion_func (wq);
  
  return 0;
}
Commit	Line	Data
354d119a	1	/*
	2	* Quagga Work Queue Support.
	3	*
	4	* Copyright (C) 2005 Sun Microsystems, Inc.
	5	*
	6	* This file is part of GNU Zebra.
	7	*
	8	* Quagga is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2, or (at your option) any
	11	* later version.
	12	*
	13	* Quagga is distributed in the hope that it will be useful, but
	14	* WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	16	* General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with Quagga; see the file COPYING. If not, write to the Free
	20	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
	21	* 02111-1307, USA.
	22	*/
	23
	24	#include <lib/zebra.h>
	25	#include "thread.h"
	26	#include "memory.h"
	27	#include "workqueue.h"
	28	#include "linklist.h"
	29	#include "command.h"
	30	#include "log.h"
	31
	32	/* master list of work_queues */
	33	static struct list work_queues;
	34
	35	#define WORK_QUEUE_MIN_GRANULARITY 1
	36
	37	static struct work_queue_item *
	38	work_queue_item_new (struct work_queue *wq)
	39	{
	40	struct work_queue_item *item;
	41	assert (wq);
	42
	43	item = XCALLOC (MTYPE_WORK_QUEUE_ITEM,
	44	sizeof (struct work_queue_item));
	45
	46	return item;
	47	}
	48
	49	static void
	50	work_queue_item_free (struct work_queue_item *item)
	51	{
	52	XFREE (MTYPE_WORK_QUEUE_ITEM, item);
	53	return;
	54	}
	55
	56	/* create new work queue */
	57	struct work_queue *
	58	work_queue_new (struct thread_master m, const char queue_name)
	59	{
	60	struct work_queue *new;
	61
	62	new = XCALLOC (MTYPE_WORK_QUEUE, sizeof (struct work_queue));
	63
	64	if (new == NULL)
65	return new;
66
67	new->name = XSTRDUP (MTYPE_WORK_QUEUE_NAME, queue_name);
68	new->master = m;
6ce80bdb	69	SET_FLAG (new->flags, WQ_UNPLUGGED);
354d119a	70
	71	if ( (new->items = list_new ()) == NULL)
	72	{
354d119a	73	XFREE (MTYPE_WORK_QUEUE_NAME, new->name);
	74	XFREE (MTYPE_WORK_QUEUE, new);
	75
	76	return NULL;
	77	}
	78
	79	new->items->del = (void ()(void )) work_queue_item_free;
	80
	81	listnode_add (&work_queues, new);
	82
	83	new->cycles.granularity = WORK_QUEUE_MIN_GRANULARITY;
190880dc	84
190880dc	85	/* Default values, can be overriden by caller */
190880dc	86	new->spec.hold = WORK_QUEUE_DEFAULT_HOLD;
50596be0	87	new->spec.yield = THREAD_YIELD_TIME_SLOT;
190880dc	88
354d119a	89	return new;
	90	}
	91
	92	void
	93	work_queue_free (struct work_queue *wq)
	94	{
acde4b86 SH	95	if (wq->thread != NULL)
	96	thread_cancel(wq->thread);
	97
354d119a	98	/* list_delete frees items via callback */
	99	list_delete (wq->items);
	100	listnode_delete (&work_queues, wq);
	101
	102	XFREE (MTYPE_WORK_QUEUE_NAME, wq->name);
	103	XFREE (MTYPE_WORK_QUEUE, wq);
	104	return;
	105	}
	106
f63f06da	107	static int
269d74fd	108	work_queue_schedule (struct work_queue *wq, unsigned int delay)
	109	{
	110	/* if appropriate, schedule work queue thread */
6ce80bdb	111	if ( CHECK_FLAG (wq->flags, WQ_UNPLUGGED)
269d74fd	112	&& (wq->thread == NULL)
	113	&& (listcount (wq->items) > 0) )
	114	{
	115	wq->thread = thread_add_background (wq->master, work_queue_run,
	116	wq, delay);
50596be0 DS	117	/* set thread yield time, if needed */
	118	if (wq->thread && wq->spec.yield != THREAD_YIELD_TIME_SLOT)
	119	thread_set_yield_time (wq->thread, wq->spec.yield);
269d74fd	120	return 1;
	121	}
	122	else
	123	return 0;
	124	}
	125
354d119a	126	void
	127	work_queue_add (struct work_queue wq, void data)
	128	{
	129	struct work_queue_item *item;
	130
	131	assert (wq);
	132
	133	if (!(item = work_queue_item_new (wq)))
	134	{
	135	zlog_err ("%s: unable to get new queue item", __func__);
	136	return;
	137	}
	138
	139	item->data = data;
e96f9203	140	listnode_add (wq->items, item);
354d119a	141
306d8890	142	work_queue_schedule (wq, wq->spec.hold);
354d119a	143
	144	return;
	145	}
	146
	147	static void
	148	work_queue_item_remove (struct work_queue wq, struct listnode ln)
	149	{
	150	struct work_queue_item *item = listgetdata (ln);
	151
	152	assert (item && item->data);
	153
	154	/* call private data deletion callback if needed */
	155	if (wq->spec.del_item_data)
889e9311	156	wq->spec.del_item_data (wq, item->data);
354d119a	157
	158	list_delete_node (wq->items, ln);
	159	work_queue_item_free (item);
	160
	161	return;
	162	}
	163
	164	static void
	165	work_queue_item_requeue (struct work_queue wq, struct listnode ln)
	166	{
	167	LISTNODE_DETACH (wq->items, ln);
	168	LISTNODE_ATTACH (wq->items, ln); /* attach to end of list */
	169	}
	170
	171	DEFUN(show_work_queues,
	172	show_work_queues_cmd,
	173	"show work-queues",
	174	SHOW_STR
	175	"Work Queue information\n")
	176	{
	177	struct listnode *node;
	178	struct work_queue *wq;
354d119a	179
354d119a	180	vty_out (vty,
50596be0 DS	181	"%c %8s %5s %8s %8s %21s%s",
50596be0 DS	182	' ', "List","(ms) ","Q. Runs","Yields","Cycle Counts ",
354d119a	183	VTY_NEWLINE);
354d119a	184	vty_out (vty,
50596be0	185	"%c %8s %5s %8s %8s %7s %6s %8s %6s %s%s",
306d8890	186	'P',
354d119a	187	"Items",
306d8890	188	"Hold",
50596be0 DS	189	"Total","Total",
50596be0 DS	190	"Best","Gran.","Total","Avg.",
354d119a	191	"Name",
	192	VTY_NEWLINE);
	193
	194	for (ALL_LIST_ELEMENTS_RO ((&work_queues), node, wq))
	195	{
50596be0	196	vty_out (vty,"%c %8d %5d %8ld %8ld %7d %6d %8ld %6u %s%s",
6ce80bdb	197	(CHECK_FLAG (wq->flags, WQ_UNPLUGGED) ? ' ' : 'P'),
354d119a	198	listcount (wq->items),
306d8890	199	wq->spec.hold,
50596be0 DS	200	wq->runs, wq->yields,
50596be0 DS	201	wq->cycles.best, wq->cycles.granularity, wq->cycles.total,
84369684	202	(wq->runs) ?
84369684	203	(unsigned int) (wq->cycles.total / wq->runs) : 0,
354d119a	204	wq->name,
	205	VTY_NEWLINE);
	206	}
	207
	208	return CMD_SUCCESS;
	209	}
	210
269d74fd	211	/* 'plug' a queue: Stop it from being scheduled,
	212	* ie: prevent the queue from draining.
	213	*/
	214	void
	215	work_queue_plug (struct work_queue *wq)
	216	{
	217	if (wq->thread)
	218	thread_cancel (wq->thread);
	219
	220	wq->thread = NULL;
	221
6ce80bdb	222	UNSET_FLAG (wq->flags, WQ_UNPLUGGED);
269d74fd	223	}
	224
	225	/* unplug queue, schedule it again, if appropriate
	226	* Ie: Allow the queue to be drained again
	227	*/
	228	void
	229	work_queue_unplug (struct work_queue *wq)
	230	{
6ce80bdb	231	SET_FLAG (wq->flags, WQ_UNPLUGGED);
269d74fd	232
269d74fd	233	/* if thread isnt already waiting, add one */
306d8890	234	work_queue_schedule (wq, wq->spec.hold);
269d74fd	235	}
269d74fd	236
354d119a	237	/* timer thread to process a work queue
	238	* will reschedule itself if required,
	239	* otherwise work_queue_item_add
	240	*/
	241	int
	242	work_queue_run (struct thread *thread)
	243	{
	244	struct work_queue *wq;
	245	struct work_queue_item *item;
	246	wq_item_status ret;
	247	unsigned int cycles = 0;
	248	struct listnode node, nnode;
	249	char yielded = 0;
	250
	251	wq = THREAD_ARG (thread);
	252	wq->thread = NULL;
	253
	254	assert (wq && wq->items);
	255
	256	/* calculate cycle granularity:
50596be0 DS	257	* list iteration == 1 run
50596be0 DS	258	* listnode processing == 1 cycle
354d119a	259	* granularity == # cycles between checks whether we should yield.
	260	*
	261	* granularity should be > 0, and can increase slowly after each run to
	262	* provide some hysteris, but not past cycles.best or 2*cycles.
	263	*
	264	* Best: starts low, can only increase
	265	*
213d8dad PJ	266	* Granularity: starts at WORK_QUEUE_MIN_GRANULARITY, can be decreased
	267	* if we run to end of time slot, can increase otherwise
	268	* by a small factor.
354d119a	269	*
	270	* We could use just the average and save some work, however we want to be
	271	* able to adjust quickly to CPU pressure. Average wont shift much if
	272	* daemon has been running a long time.
	273	*/
	274	if (wq->cycles.granularity == 0)
	275	wq->cycles.granularity = WORK_QUEUE_MIN_GRANULARITY;
	276
	277	for (ALL_LIST_ELEMENTS (wq->items, node, nnode, item))
	278	{
	279	assert (item && item->data);
	280
	281	/* dont run items which are past their allowed retries */
84369684	282	if (item->ran > wq->spec.max_retries)
354d119a	283	{
	284	/* run error handler, if any */
	285	if (wq->spec.errorfunc)
	286	wq->spec.errorfunc (wq, item->data);
	287	work_queue_item_remove (wq, node);
	288	continue;
	289	}
	290
	291	/* run and take care of items that want to be retried immediately */
	292	do
	293	{
889e9311	294	ret = wq->spec.workfunc (wq, item->data);
84369684	295	item->ran++;
354d119a	296	}
354d119a	297	while ((ret == WQ_RETRY_NOW)
84369684	298	&& (item->ran < wq->spec.max_retries));
354d119a	299
	300	switch (ret)
	301	{
269d74fd	302	case WQ_QUEUE_BLOCKED:
	303	{
	304	/* decrement item->ran again, cause this isn't an item
	305	* specific error, and fall through to WQ_RETRY_LATER
	306	*/
	307	item->ran--;
	308	}
354d119a	309	case WQ_RETRY_LATER:
354d119a	310	{
354d119a	311	goto stats;
	312	}
	313	case WQ_REQUEUE:
	314	{
e96f9203	315	item->ran--;
354d119a	316	work_queue_item_requeue (wq, node);
50596be0 DS	317	/* If a single node is being used with a meta-queue (e.g., zebra),
	318	* update the next node as we don't want to exit the thread and
	319	* reschedule it after every node. By definition, WQ_REQUEUE is
	320	* meant to continue the processing; the yield logic will kick in
	321	* to terminate the thread when time has exceeded.
	322	*/
	323	if (nnode == NULL)
	324	nnode = node;
354d119a	325	break;
	326	}
	327	case WQ_RETRY_NOW:
269d74fd	328	/* a RETRY_NOW that gets here has exceeded max_tries, same as ERROR */
354d119a	329	case WQ_ERROR:
	330	{
	331	if (wq->spec.errorfunc)
	332	wq->spec.errorfunc (wq, item);
	333	}
	334	/* fall through here is deliberate */
	335	case WQ_SUCCESS:
	336	default:
	337	{
	338	work_queue_item_remove (wq, node);
	339	break;
	340	}
	341	}
	342
	343	/* completed cycle */
	344	cycles++;
	345
	346	/* test if we should yield */
	347	if ( !(cycles % wq->cycles.granularity)
	348	&& thread_should_yield (thread))
	349	{
	350	yielded = 1;
	351	goto stats;
	352	}
	353	}
	354
	355	stats:
	356
3322055b	357	#define WQ_HYSTERESIS_FACTOR 4
354d119a	358
	359	/* we yielded, check whether granularity should be reduced */
	360	if (yielded && (cycles < wq->cycles.granularity))
	361	{
50596be0	362	wq->cycles.granularity = ((cycles > 0) ? cycles
354d119a	363	: WORK_QUEUE_MIN_GRANULARITY);
354d119a	364	}
3322055b PJ	365	/* otherwise, should granularity increase? */
3322055b PJ	366	else if (cycles >= (wq->cycles.granularity))
354d119a	367	{
	368	if (cycles > wq->cycles.best)
	369	wq->cycles.best = cycles;
50596be0	370
3322055b PJ	371	/* along with yielded check, provides hysteresis for granularity */
	372	if (cycles > (wq->cycles.granularity * WQ_HYSTERESIS_FACTOR
	373	* WQ_HYSTERESIS_FACTOR))
	374	wq->cycles.granularity = WQ_HYSTERESIS_FACTOR; / quick ramp-up */
	375	else if (cycles > (wq->cycles.granularity * WQ_HYSTERESIS_FACTOR))
	376	wq->cycles.granularity += WQ_HYSTERESIS_FACTOR;
354d119a	377	}
	378	#undef WQ_HYSTERIS_FACTOR
	379
	380	wq->runs++;
	381	wq->cycles.total += cycles;
50596be0 DS	382	if (yielded)
50596be0 DS	383	wq->yields++;
354d119a	384
	385	#if 0
	386	printf ("%s: cycles %d, new: best %d, worst %d\n",
	387	__func__, cycles, wq->cycles.best, wq->cycles.granularity);
	388	#endif
	389
269d74fd	390	/* Is the queue done yet? If it is, call the completion callback. */
354d119a	391	if (listcount (wq->items) > 0)
306d8890	392	work_queue_schedule (wq, 0);
	393	else if (wq->spec.completion_func)
	394	wq->spec.completion_func (wq);
269d74fd	395
354d119a	396	return 0;
354d119a	397	}