diff options
| -rw-r--r-- | rts/Capability.c | 12 | ||||
| -rw-r--r-- | rts/Schedule.c | 4 | ||||
| -rw-r--r-- | rts/Sparks.c | 26 | ||||
| -rw-r--r-- | rts/Sparks.h | 23 |
4 files changed, 36 insertions, 29 deletions
diff --git a/rts/Capability.c b/rts/Capability.c index fe5dbdca40..a9bb743654 100644 --- a/rts/Capability.c +++ b/rts/Capability.c @@ -92,7 +92,11 @@ findSpark (Capability *cap) // spark = reclaimSpark(cap->sparks); // However, measurements show that this makes at least one benchmark // slower (prsa) and doesn't affect the others. - spark = tryStealSpark(cap); + spark = tryStealSpark(cap->sparks); + while (spark != NULL && fizzledSpark(spark)) { + cap->sparks_fizzled++; + spark = tryStealSpark(cap->sparks); + } if (spark != NULL) { cap->sparks_converted++; @@ -121,7 +125,11 @@ findSpark (Capability *cap) if (emptySparkPoolCap(robbed)) // nothing to steal here continue; - spark = tryStealSpark(robbed); + spark = tryStealSpark(robbed->sparks); + while (spark != NULL && fizzledSpark(spark)) { + cap->sparks_fizzled++; + spark = tryStealSpark(robbed->sparks); + } if (spark == NULL && !emptySparkPoolCap(robbed)) { // we conflicted with another thread while trying to steal; // try again later. diff --git a/rts/Schedule.c b/rts/Schedule.c index 50e0663577..125f9f0b74 100644 --- a/rts/Schedule.c +++ b/rts/Schedule.c @@ -783,6 +783,10 @@ schedulePushWork(Capability *cap USED_IF_THREADS, if (emptySparkPoolCap(free_caps[i])) { spark = tryStealSpark(cap->sparks); if (spark != NULL) { + /* TODO: if anyone wants to re-enable this code then + * they must consider the fizzledSpark(spark) case + * and update the per-cap spark statistics. + */ debugTrace(DEBUG_sched, "pushing spark %p to capability %d", spark, free_caps[i]->no); traceEventStealSpark(free_caps[i], t, cap->no); diff --git a/rts/Sparks.c b/rts/Sparks.c index 18d9597ec2..5c78055e8c 100644 --- a/rts/Sparks.c +++ b/rts/Sparks.c @@ -73,32 +73,6 @@ newSpark (StgRegTable *reg, StgClosure *p) return 1; } -/* ----------------------------------------------------------------------------- - * - * tryStealSpark: try to steal a spark from a Capability. - * - * Returns a valid spark, or NULL if the pool was empty, and can - * occasionally return NULL if there was a race with another thread - * stealing from the same pool. In this case, try again later. - * - -------------------------------------------------------------------------- */ - -StgClosure * -tryStealSpark (Capability *cap) -{ - SparkPool *pool = cap->sparks; - StgClosure *stolen; - - do { - stolen = stealWSDeque_(pool); - // use the no-loopy version, stealWSDeque_(), since if we get a - // spurious NULL here the caller may want to try stealing from - // other pools before trying again. - } while (stolen != NULL && !closure_SHOULD_SPARK(stolen)); - - return stolen; -} - /* -------------------------------------------------------------------------- * Remove all sparks from the spark queues which should not spark any * more. Called after GC. We assume exclusive access to the structure diff --git a/rts/Sparks.h b/rts/Sparks.h index d714cb5d09..e3ddc0cfaa 100644 --- a/rts/Sparks.h +++ b/rts/Sparks.h @@ -30,7 +30,7 @@ INLINE_HEADER StgClosure* reclaimSpark(SparkPool *pool); // if the pool is almost empty). INLINE_HEADER rtsBool looksEmpty(SparkPool* deque); -StgClosure * tryStealSpark (Capability *cap); +INLINE_HEADER StgClosure * tryStealSpark (SparkPool *cap); INLINE_HEADER rtsBool fizzledSpark (StgClosure *); void freeSparkPool (SparkPool *pool); @@ -65,6 +65,27 @@ INLINE_HEADER void discardSparks (SparkPool *pool) discardElements(pool); } +/* ---------------------------------------------------------------------------- + * + * tryStealSpark: try to steal a spark from a Capability. + * + * Returns either: + * (a) a useful spark; + * (b) a fizzled spark (use fizzledSpark to check); + * (c) or NULL if the pool was empty, and can occasionally return NULL + * if there was a race with another thread stealing from the same + * pool. In this case, try again later. + * + -------------------------------------------------------------------------- */ + +INLINE_HEADER StgClosure * tryStealSpark (SparkPool *pool) +{ + return stealWSDeque_(pool); + // use the no-loopy version, stealWSDeque_(), since if we get a + // spurious NULL here the caller may want to try stealing from + // other pools before trying again. +} + INLINE_HEADER rtsBool fizzledSpark (StgClosure *spark) { return (GET_CLOSURE_TAG(spark) != 0 || !closure_SHOULD_SPARK(spark)); |