From 938c10b60913d3328e459378e6feea27d364c10c Mon Sep 17 00:00:00 2001
From: Pedro Gonnet <pedro.gonnet@durham.ac.uk>
Date: Fri, 5 Jul 2013 12:30:55 +0000
Subject: [PATCH] try several steals after a failed get attempt on the
preferred queue.
Former-commit-id: d0abb3e20eb09afe730495ce622866b8b8cf3fc2
---
src/scheduler.c | 11 +++++++++--
src/scheduler.h | 3 ++-
2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/src/scheduler.c b/src/scheduler.c
index 84c6608cbd..93bcbc0f98 100644
--- a/src/scheduler.c
+++ b/src/scheduler.c
@@ -847,7 +847,7 @@ struct task *scheduler_gettask ( struct scheduler *s , int qid , struct cell *su
while ( s->waiting > 0 && res == NULL ) {
/* Try more than once before sleeping. */
- for ( int tries = 0 ; res == NULL && tries < scheduler_flag_maxsteal ; tries++ ) {
+ for ( int tries = 0 ; res == NULL && tries < scheduler_maxtries ; tries++ ) {
/* Try to get a task from the suggested queue. */
if ( ( res = queue_gettask( &s->queues[qid] , qid , super , 0 ) ) != NULL )
@@ -859,7 +859,14 @@ struct task *scheduler_gettask ( struct scheduler *s , int qid , struct cell *su
for ( k = 0 ; k < nr_queues ; k++ )
if ( s->queues[k].count > 0 )
qids[ count++ ] = k;
- if ( count > 0 && ( res = queue_gettask( &s->queues[ qids[ rand() % count ] ] , qid , super , 0 ) ) != NULL )
+ for ( k = 0 ; k < scheduler_maxsteal && count > 0 ; k++ ) {
+ int ind = rand() % count;
+ if ( ( res = queue_gettask( &s->queues[ qids[ ind ] ] , qid , super , 0 ) ) != NULL )
+ break;
+ else
+ qids[ ind ] = qids[ --count ];
+ }
+ if ( res != NULL )
break;
}
diff --git a/src/scheduler.h b/src/scheduler.h
index b8ae07ed35..46b196f4b6 100644
--- a/src/scheduler.h
+++ b/src/scheduler.h
@@ -22,11 +22,12 @@
#define scheduler_maxwait 3
#define scheduler_maxunlock 40
#define scheduler_dosub 1
+#define scheduler_maxsteal 10
+#define scheduler_maxtries 10
/* Flags . */
#define scheduler_flag_none 0
#define scheduler_flag_steal 1
-#define scheduler_flag_maxsteal 10
/* Data of a scheduler. */
--
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