Commit e54b2d82 authored by Pedro Gonnet's avatar Pedro Gonnet
Browse files

add biased task selection.


Former-commit-id: f227d3fda832ff4b0f0da54d44612bdfa88eaa97
parent 74221955
......@@ -73,6 +73,9 @@ struct cell {
/* Spin lock for various uses. */
lock_type lock;
/* ID of the previous owner, e.g. runner. */
int owner;
/* Linking pointer for "memory management". */
struct cell *next;
......
......@@ -84,6 +84,34 @@ int queue_counter[ queue_counter_count ];
/**
* @brief Insert a used tasks into the given queue.
*
* @param q The #queue.
* @param t The #task.
*/
void queue_insert ( struct queue *q , struct task *t ) {
int k;
/* Lock the queue. */
if ( lock_lock( &q->lock ) != 0 )
error( "Failed to get queue lock." );
/* Bubble-up the tasks. */
for ( k = q->count ; k > q->next ; k-- )
q->tid[k] = q->tid[k-1];
q->tid[ q->next ] = t - q->tasks;
q->count += 1;
q->next += 1;
/* Unlock the queue. */
if ( lock_unlock( &q->lock ) != 0 )
error( "Failed to unlock queue." );
}
/**
* @brief Initialize the given queue.
*
......@@ -239,6 +267,152 @@ struct task *queue_gettask ( struct queue *q , int blocking , int keep ) {
}
struct task *queue_gettask_new ( struct queue *q , int rid , int blocking , int keep ) {
int k, tid = -1, qcount, *qtid = q->tid;
lock_type *qlock = &q->lock;
struct task *qtasks = q->tasks, *res = NULL;
int ind_best, score_best = -1, score;
TIMER_TIC
/* If there are no tasks, leave immediately. */
if ( q->next >= q->count ) {
TIMER_TOC(queue_timer_gettask);
return NULL;
}
/* Main loop, while there are tasks... */
while ( q->next < q->count ) {
/* Grab the task lock. */
// if ( blocking ) {
if ( lock_lock( qlock ) != 0 )
error( "Locking the task_lock failed.\n" );
// }
// else {
// if ( lock_trylock( qlock ) != 0 )
// break;
// }
/* Loop over the remaining task IDs. */
qcount = q->count; ind_best = -1;
for ( k = q->next ; k < qcount ; k++ ) {
/* Put a finger on the task. */
res = &qtasks[ qtid[k] ];
/* Is this task blocked? */
if ( res->wait )
continue;
/* Get the score for this task. */
if ( res->type == tid_self || res->type == tid_sort || ( res->type == tid_sub && res->cj == NULL ) )
score = ( res->ci->owner == rid );
else
score = ( res->ci->owner == rid ) + ( res->cj->owner == rid );
if ( score <= score_best )
continue;
/* Different criteria for different types. */
if ( res->type == tid_self || (res->type == tid_sub && res->cj == NULL) ) {
if ( res->ci->hold || cell_locktree( res->ci ) != 0 )
continue;
}
else if ( res->type == tid_pair || (res->type == tid_sub && res->cj != NULL) ) {
if ( res->ci->hold || res->cj->hold || res->ci->wait || res->cj->wait )
continue;
if ( cell_locktree( res->ci ) != 0 )
continue;
if ( cell_locktree( res->cj ) != 0 ) {
cell_unlocktree( res->ci );
continue;
}
}
/* If we owned a previous task, unlock it. */
if ( ind_best >= 0 ) {
res = &qtasks[ qtid[ ind_best ] ];
if ( res->type == tid_self || res->type == tid_pair || res->type == tid_sub )
cell_unlocktree( res->ci );
if ( res->type == tid_pair || (res->type == tid_sub && res->cj != NULL) )
cell_unlocktree( res->cj );
}
/* If we made it this far, we're safe. */
ind_best = k;
score_best = score;
/* Should we bother looking any farther? */
if ( score_best == 2 )
break;
} /* loop over the task IDs. */
/* Did we get a task? */
if ( ind_best >= 0 ) {
/* Do we need to swap? */
if ( ind_best != q->next )
COUNT(queue_counter_swap);
/* get the task ID. */
tid = qtid[ ind_best ];
/* Own the cells involved. */
qtasks[ tid ].ci->owner = rid;
if ( qtasks[ tid ].cj != NULL )
qtasks[ tid ].cj->owner = rid;
/* Remove the task? */
if ( keep ) {
/* Bubble-up. */
q->count = qcount - 1;
for ( k = ind_best ; k < qcount - 1 ; k++ )
qtid[k] = qtid[k+1];
}
/* No, leave it in the queue. */
else {
TIMER_TIC2
/* Bubble-down the task. */
for ( k = ind_best ; k > q->next ; k-- )
qtid[ k ] = qtid[ k-1 ];
qtid[ q->next ] = tid;
/* up the counter. */
q->next += 1;
TIMER_TOC2(queue_timer_bubble);
}
}
/* Release the task lock. */
if ( lock_unlock( qlock ) != 0 )
error( "Unlocking the task_lock failed.\n" );
/* Leave? */
if ( tid >= 0 ) {
TIMER_TOC(queue_timer_gettask);
return &qtasks[tid];
}
else if ( !blocking )
break;
} /* while there are tasks. */
/* No beef. */
TIMER_TOC(queue_timer_gettask);
return NULL;
}
/**
* @brief Sort the tasks IDs according to their weight and constraints.
*
......
......@@ -56,5 +56,7 @@ struct queue {
/* Function prototypes. */
struct task *queue_gettask ( struct queue *q , int blocking , int keep );
struct task *queue_gettask_new ( struct queue *q , int rid , int blocking , int keep );
void queue_init ( struct queue *q , int size , struct task *tasks );
void queue_insert ( struct queue *q , struct task *t );
void queue_sort ( struct queue *q );
......@@ -1030,7 +1030,6 @@ void *runner_main ( void *data ) {
struct runner_thread *rt = (struct runner_thread *)data;
struct runner *r = rt->r;
struct space *s = r->s;
int threadID = rt->id;
int k, qid, naq, keep, tpq;
struct queue *queues[ r->nr_queues ], *myq;
......@@ -1080,11 +1079,11 @@ void *runner_main ( void *data ) {
TIMER_TIC
t = NULL;
if ( r->nr_queues == 1 ) {
t = queue_gettask( &r->queues[0] , 1 , 0 );
t = queue_gettask_new( &r->queues[0] , rt->id , 1 , 0 );
}
else if ( r->policy & runner_policy_steal ) {
if ( ( myq->next == myq->count ) ||
( t = queue_gettask( myq , 0 , 0 ) ) == NULL ) {
( t = queue_gettask_new( myq , rt->id , 0 , 0 ) ) == NULL ) {
TIMER_TIC2
qid = rand_r( &myseed ) % naq;
keep = ( r->policy & runner_policy_keep ) &&
......@@ -1093,19 +1092,9 @@ void *runner_main ( void *data ) {
COUNT(runner_counter_steal_empty);
else
COUNT(runner_counter_steal_stall);
t = queue_gettask( queues[qid] , 0 , keep );
if ( t != NULL && keep ) {
COUNT(runner_counter_keep);
if ( lock_lock( &myq->lock ) != 0 )
error( "Failed to get queue lock." );
for ( k = myq->count ; k > myq->next ; k-- )
myq->tid[k] = myq->tid[k-1];
myq->tid[ myq->next ] = t - s->tasks;
myq->count += 1;
myq->next += 1;
if ( lock_unlock( &myq->lock ) != 0 )
error( "Failed to unlock queue." );
}
t = queue_gettask_new( queues[qid] , rt->id , 0 , keep );
if ( t != NULL && keep )
queue_insert( myq , t );
TIMER_TOC2(runner_timer_steal);
}
}
......
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