X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FGC.c;h=bf5d612549e8b65f9409a30ab014795ebd3ea991;hb=91b07216be1cb09230b7d1b417899ddea8620ff3;hp=f2d9437551fa312c6576acc2d4ebf3a0f5ef2b9d;hpb=de910f06ebec544c71cd5c41dbb11937812c7a1a;p=ghc-hetmet.git

diff --git a/ghc/rts/GC.c b/ghc/rts/GC.c
index f2d9437..bf5d612 100644
--- a/ghc/rts/GC.c
+++ b/ghc/rts/GC.c
@@ -104,6 +104,10 @@ static rtsBool major_gc;
  */
 static nat evac_gen;
 
+/* Whether to do eager promotion or not.
+ */
+static rtsBool eager_promotion;
+
 /* Weak pointers
  */
 StgWeak *old_weak_ptr_list; // also pending finaliser list
@@ -585,6 +589,8 @@ GarbageCollect ( void (*get_roots)(evac_fn), rtsBool force_major_gc )
       mark_stack_bdescr = NULL;
   }
 
+  eager_promotion = rtsTrue; // for now
+
   /* -----------------------------------------------------------------------
    * follow all the roots that we know about:
    *   - mutable lists from each generation > N
@@ -1567,11 +1573,11 @@ copy(StgClosure *src, nat size, step *stp)
    * by evacuate()).
    */
   if (stp->gen_no < evac_gen) {
-#ifdef NO_EAGER_PROMOTION    
-    failed_to_evac = rtsTrue;
-#else
-    stp = &generations[evac_gen].steps[0];
-#endif
+      if (eager_promotion) {
+	  stp = &generations[evac_gen].steps[0];
+      } else {
+	  failed_to_evac = rtsTrue;
+      }
   }
 
   /* chain a new block onto the to-space for the destination step if
@@ -1617,11 +1623,11 @@ copy_noscav(StgClosure *src, nat size, step *stp)
    * by evacuate()).
    */
   if (stp->gen_no < evac_gen) {
-#ifdef NO_EAGER_PROMOTION    
-    failed_to_evac = rtsTrue;
-#else
-    stp = &generations[evac_gen].steps[0];
-#endif
+      if (eager_promotion) {
+	  stp = &generations[evac_gen].steps[0];
+      } else {
+	  failed_to_evac = rtsTrue;
+      }
   }
 
   /* chain a new block onto the to-space for the destination step if
@@ -1664,11 +1670,11 @@ copyPart(StgClosure *src, nat size_to_reserve, nat size_to_copy, step *stp)
 
   TICK_GC_WORDS_COPIED(size_to_copy);
   if (stp->gen_no < evac_gen) {
-#ifdef NO_EAGER_PROMOTION    
-    failed_to_evac = rtsTrue;
-#else
-    stp = &generations[evac_gen].steps[0];
-#endif
+      if (eager_promotion) {
+	  stp = &generations[evac_gen].steps[0];
+      } else {
+	  failed_to_evac = rtsTrue;
+      }
   }
 
   if (stp->hp + size_to_reserve >= stp->hpLim) {
@@ -1745,11 +1751,11 @@ evacuate_large(StgPtr p)
    */
   stp = bd->step->to;
   if (stp->gen_no < evac_gen) {
-#ifdef NO_EAGER_PROMOTION    
-    failed_to_evac = rtsTrue;
-#else
-    stp = &generations[evac_gen].steps[0];
-#endif
+      if (eager_promotion) {
+	  stp = &generations[evac_gen].steps[0];
+      } else {
+	  failed_to_evac = rtsTrue;
+      }
   }
 
   bd->step = stp;
@@ -1935,7 +1941,8 @@ loop:
   
   switch (info->type) {
 
-  case MUT_VAR:
+  case MUT_VAR_CLEAN:
+  case MUT_VAR_DIRTY:
   case MVAR:
       return copy(q,sizeW_fromITBL(info),stp);
 
@@ -2105,7 +2112,8 @@ loop:
       // just copy the block 
       return copy_noscav(q,arr_words_sizeW((StgArrWords *)q),stp);
 
-  case MUT_ARR_PTRS:
+  case MUT_ARR_PTRS_CLEAN:
+  case MUT_ARR_PTRS_DIRTY:
   case MUT_ARR_PTRS_FROZEN:
   case MUT_ARR_PTRS_FROZEN0:
       // just copy the block 
@@ -2887,13 +2895,22 @@ scavenge(step *stp)
 	p += sizeofW(StgInd);
 	break;
 
-    case MUT_VAR:
-	evac_gen = 0;
+    case MUT_VAR_CLEAN:
+    case MUT_VAR_DIRTY: {
+	rtsBool saved_eager_promotion = eager_promotion;
+
+	eager_promotion = rtsFalse;
 	((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
-	evac_gen = saved_evac_gen;
-	failed_to_evac = rtsTrue; // mutable anyhow
+	eager_promotion = saved_eager_promotion;
+
+	if (failed_to_evac) {
+	    ((StgClosure *)q)->header.info = &stg_MUT_VAR_DIRTY_info;
+	} else {
+	    ((StgClosure *)q)->header.info = &stg_MUT_VAR_CLEAN_info;
+	}
 	p += sizeofW(StgMutVar);
 	break;
+    }
 
     case CAF_BLACKHOLE:
     case SE_CAF_BLACKHOLE:
@@ -2934,18 +2951,32 @@ scavenge(step *stp)
 	p += arr_words_sizeW((StgArrWords *)p);
 	break;
 
-    case MUT_ARR_PTRS:
+    case MUT_ARR_PTRS_CLEAN:
+    case MUT_ARR_PTRS_DIRTY:
 	// follow everything 
     {
 	StgPtr next;
-
-	evac_gen = 0;		// repeatedly mutable 
+	rtsBool saved_eager;
+
+	// We don't eagerly promote objects pointed to by a mutable
+	// array, but if we find the array only points to objects in
+	// the same or an older generation, we mark it "clean" and
+	// avoid traversing it during minor GCs.
+	saved_eager = eager_promotion;
+	eager_promotion = rtsFalse;
 	next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
 	for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
 	    *p = (StgWord)(StgPtr)evacuate((StgClosure *)*p);
 	}
-	evac_gen = saved_evac_gen;
-	failed_to_evac = rtsTrue; // mutable anyhow.
+	eager_promotion = saved_eager;
+
+	if (failed_to_evac) {
+	    ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+	} else {
+	    ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+	}
+
+	failed_to_evac = rtsTrue; // always put it on the mutable list.
 	break;
     }
 
@@ -3256,12 +3287,21 @@ linear_scan:
 		evacuate(((StgInd *)p)->indirectee);
 	    break;
 
-	case MUT_VAR:
-	    evac_gen = 0;
+	case MUT_VAR_CLEAN:
+	case MUT_VAR_DIRTY: {
+	    rtsBool saved_eager_promotion = eager_promotion;
+	    
+	    eager_promotion = rtsFalse;
 	    ((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
-	    evac_gen = saved_evac_gen;
-	    failed_to_evac = rtsTrue;
+	    eager_promotion = saved_eager_promotion;
+	    
+	    if (failed_to_evac) {
+		((StgClosure *)q)->header.info = &stg_MUT_VAR_DIRTY_info;
+	    } else {
+		((StgClosure *)q)->header.info = &stg_MUT_VAR_CLEAN_info;
+	    }
 	    break;
+	}
 
 	case CAF_BLACKHOLE:
 	case SE_CAF_BLACKHOLE:
@@ -3295,17 +3335,31 @@ linear_scan:
 	    scavenge_AP((StgAP *)p);
 	    break;
       
-	case MUT_ARR_PTRS:
+	case MUT_ARR_PTRS_CLEAN:
+	case MUT_ARR_PTRS_DIRTY:
 	    // follow everything 
 	{
 	    StgPtr next;
-	    
-	    evac_gen = 0;		// repeatedly mutable 
+	    rtsBool saved_eager;
+
+	    // We don't eagerly promote objects pointed to by a mutable
+	    // array, but if we find the array only points to objects in
+	    // the same or an older generation, we mark it "clean" and
+	    // avoid traversing it during minor GCs.
+	    saved_eager = eager_promotion;
+	    eager_promotion = rtsFalse;
 	    next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
 	    for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
 		*p = (StgWord)(StgPtr)evacuate((StgClosure *)*p);
 	    }
-	    evac_gen = saved_evac_gen;
+	    eager_promotion = saved_eager;
+
+	    if (failed_to_evac) {
+		((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+	    } else {
+		((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+	    }
+
 	    failed_to_evac = rtsTrue; // mutable anyhow.
 	    break;
 	}
@@ -3572,12 +3626,22 @@ scavenge_one(StgPtr p)
 	break;
     }
     
-    case MUT_VAR:
-	evac_gen = 0;
+    case MUT_VAR_CLEAN:
+    case MUT_VAR_DIRTY: {
+	StgPtr q = p;
+	rtsBool saved_eager_promotion = eager_promotion;
+
+	eager_promotion = rtsFalse;
 	((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
-	evac_gen = saved_evac_gen;
-	failed_to_evac = rtsTrue; // mutable anyhow
+	eager_promotion = saved_eager_promotion;
+
+	if (failed_to_evac) {
+	    ((StgClosure *)q)->header.info = &stg_MUT_VAR_DIRTY_info;
+	} else {
+	    ((StgClosure *)q)->header.info = &stg_MUT_VAR_CLEAN_info;
+	}
 	break;
+    }
 
     case CAF_BLACKHOLE:
     case SE_CAF_BLACKHOLE:
@@ -3614,17 +3678,31 @@ scavenge_one(StgPtr p)
 	// nothing to follow 
 	break;
 
-    case MUT_ARR_PTRS:
+    case MUT_ARR_PTRS_CLEAN:
+    case MUT_ARR_PTRS_DIRTY:
     {
-	// follow everything 
-	StgPtr next;
-      
-	evac_gen = 0;		// repeatedly mutable 
+	StgPtr next, q;
+	rtsBool saved_eager;
+
+	// We don't eagerly promote objects pointed to by a mutable
+	// array, but if we find the array only points to objects in
+	// the same or an older generation, we mark it "clean" and
+	// avoid traversing it during minor GCs.
+	saved_eager = eager_promotion;
+	eager_promotion = rtsFalse;
+	q = p;
 	next = p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
 	for (p = (P_)((StgMutArrPtrs *)p)->payload; p < next; p++) {
 	    *p = (StgWord)(StgPtr)evacuate((StgClosure *)*p);
 	}
-	evac_gen = saved_evac_gen;
+	eager_promotion = saved_eager;
+
+	if (failed_to_evac) {
+	    ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_DIRTY_info;
+	} else {
+	    ((StgClosure *)q)->header.info = &stg_MUT_ARR_PTRS_CLEAN_info;
+	}
+
 	failed_to_evac = rtsTrue;
 	break;
     }
@@ -3843,9 +3921,12 @@ scavenge_mutable_list(generation *gen)
 
 #ifdef DEBUG	    
 	    switch (get_itbl((StgClosure *)p)->type) {
-	    case MUT_VAR:
+	    case MUT_VAR_CLEAN:
+		barf("MUT_VAR_CLEAN on mutable list");
+	    case MUT_VAR_DIRTY:
 		mutlist_MUTVARS++; break;
-	    case MUT_ARR_PTRS:
+	    case MUT_ARR_PTRS_CLEAN:
+	    case MUT_ARR_PTRS_DIRTY:
 	    case MUT_ARR_PTRS_FROZEN:
 	    case MUT_ARR_PTRS_FROZEN0:
 		mutlist_MUTARRS++; break;
@@ -3854,6 +3935,13 @@ scavenge_mutable_list(generation *gen)
 	    }
 #endif
 
+	    // We don't need to scavenge clean arrays.  This is the
+	    // Whole Point of MUT_ARR_PTRS_CLEAN.
+	    if (get_itbl((StgClosure *)p)->type == MUT_ARR_PTRS_CLEAN) {
+		recordMutableGen((StgClosure *)p,gen);
+		continue;
+	    }
+
 	    if (scavenge_one(p)) {
 		/* didn't manage to promote everything, so put the
 		 * object back on the list.