From 26dc003b9ca80ca56ce203bfda23a5d01ff4b404 Mon Sep 17 00:00:00 2001
From: Pedro Gonnet <pedro.gonnet@durham.ac.uk>
Date: Mon, 3 Dec 2012 20:19:51 +0000
Subject: [PATCH] better task selection in queues.
Former-commit-id: 23fa519ca82863e510757674d30856106b9b62fa
---
src/cell.c | 2 +-
src/queue.c | 24 +++++++++++++++---------
2 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/src/cell.c b/src/cell.c
index c8fb2901cb..bfcecc94d9 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -83,7 +83,7 @@ int cell_locktree( struct cell *c ) {
TIMER_TIC
/* First of all, try to lock this cell. */
- if ( lock_trylock( &c->lock ) != 0 ) {
+ if ( c->hold || lock_trylock( &c->lock ) != 0 ) {
TIMER_TOC(cell_timer_tree);
return 1;
}
diff --git a/src/queue.c b/src/queue.c
index 79edee4d28..320d604a94 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -272,6 +272,7 @@ struct task *queue_gettask ( 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;
+ struct cell *ci_best = NULL, *cj_best = NULL;
int ind_best, score_best = -1, score;
TIMER_TIC
@@ -312,34 +313,39 @@ struct task *queue_gettask ( struct queue *q , int rid , int blocking , int keep
score = ( res->ci->owner == rid ) + ( res->cj->owner == rid );
if ( score <= score_best )
continue;
-
- /* Different criteria for different types. */
+
+ /* Try to lock ci. */
if ( res->type == task_type_self || (res->type == task_type_sub && res->cj == NULL) ) {
- if ( res->ci->hold || cell_locktree( res->ci ) != 0 )
+ if ( res->ci != ci_best && res->ci != cj_best && cell_locktree( res->ci ) != 0 )
continue;
}
else if ( res->type == task_type_pair || (res->type == task_type_sub && res->cj != NULL) ) {
if ( res->ci->hold || res->cj->hold || res->ci->wait || res->cj->wait )
continue;
- if ( cell_locktree( res->ci ) != 0 )
+ if ( res->ci != ci_best && res->ci != cj_best && cell_locktree( res->ci ) != 0 )
continue;
- if ( cell_locktree( res->cj ) != 0 ) {
- cell_unlocktree( res->ci );
+ if ( res->cj != ci_best && res->cj != cj_best && cell_locktree( res->cj ) != 0 ) {
+ if ( res->ci != ci_best && res->ci != cj_best )
+ 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 == task_type_self || res->type == task_type_pair || res->type == task_type_sub )
- cell_unlocktree( res->ci );
+ if ( res->ci != ci_best && res->ci != cj_best )
+ cell_unlocktree( res->ci );
if ( res->type == task_type_pair || (res->type == task_type_sub && res->cj != NULL) )
- cell_unlocktree( res->cj );
+ if ( res->cj != ci_best && res->cj != cj_best )
+ cell_unlocktree( res->cj );
}
/* If we made it this far, we're safe. */
ind_best = k;
+ ci_best = qtasks[ qtid[ k ] ].ci;
+ cj_best = qtasks[ qtid[ k ] ].cj;
score_best = score;
/* Should we bother looking any farther? */
--
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