Commit fa8d20e6 authored by Duncan Coutts's avatar Duncan Coutts

Classify overflowed sparks separately

When you use `par` to make a spark, if the spark pool on the current
capability is full then the spark is discarded. This represents a
loss of potential parallelism and it also means there are simply a
lot of sparks around. Both are things that might be of concern to a
programmer when tuning a parallel program that uses par.

The "+RTS -s" stats command now reports overflowed sparks, e.g.
SPARKS: 100001 (15521 converted, 84480 overflowed, 0 dud, 0 GC'd, 0 fizzled)
parent 556557eb
......@@ -234,6 +234,7 @@ initCapability( Capability *cap, nat i )
cap->inbox = (Message*)END_TSO_QUEUE;
cap->spark_stats.created = 0;
cap->spark_stats.dud = 0;
cap->spark_stats.overflowed = 0;
cap->spark_stats.converted = 0;
cap->spark_stats.gcd = 0;
cap->spark_stats.fizzled = 0;
......
......@@ -64,8 +64,12 @@ newSpark (StgRegTable *reg, StgClosure *p)
SparkPool *pool = cap->sparks;
if (!fizzledSpark(p)) {
pushWSDeque(pool,p);
cap->spark_stats.created++;
if (pushWSDeque(pool,p)) {
cap->spark_stats.created++;
} else {
/* overflowing the spark pool */
cap->spark_stats.overflowed++;
}
} else {
cap->spark_stats.dud++;
}
......
......@@ -19,6 +19,7 @@
typedef struct {
StgWord created;
StgWord dud;
StgWord overflowed;
StgWord converted;
StgWord gcd;
StgWord fizzled;
......
......@@ -629,18 +629,19 @@ stat_exit(int alloc)
{
nat i;
SparkCounters sparks = { 0, 0, 0, 0, 0};
SparkCounters sparks = { 0, 0, 0, 0, 0, 0};
for (i = 0; i < n_capabilities; i++) {
sparks.created += capabilities[i].spark_stats.created;
sparks.dud += capabilities[i].spark_stats.dud;
sparks.overflowed+= capabilities[i].spark_stats.overflowed;
sparks.converted += capabilities[i].spark_stats.converted;
sparks.gcd += capabilities[i].spark_stats.gcd;
sparks.fizzled += capabilities[i].spark_stats.fizzled;
}
statsPrintf(" SPARKS: %ld (%ld converted, %ld dud, %ld GC'd, %ld fizzled)\n\n",
sparks.created + sparks.dud,
sparks.converted, sparks.dud,
statsPrintf(" SPARKS: %ld (%ld converted, %ld overflowed, %ld dud, %ld GC'd, %ld fizzled)\n\n",
sparks.created + sparks.dud + sparks.overflowed,
sparks.converted, sparks.overflowed, sparks.dud,
sparks.gcd, sparks.fizzled);
}
#endif
......
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