[project @ 2001-08-08 14:14:08 by simonmar]

Flag tweaks: +RTS -c now means "enable compaction all the time"
(previously there was no way to do this *and* run without a maximum
heap size).

The heuristics for determining the generation sizes are also slightly
better now.

diff --git a/ghc/includes/RtsFlags.h b/ghc/includes/RtsFlags.h
index 7ecb437..4e1bcc1 100644 (file)
--- a/ghc/includes/RtsFlags.h
+++ b/ghc/includes/RtsFlags.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: RtsFlags.h,v 1.36 2001/08/07 10:11:05 simonmar Exp $
+ * $Id: RtsFlags.h,v 1.37 2001/08/08 14:14:09 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -35,7 +35,7 @@ struct GC_FLAGS {
     nat     steps;
     rtsBool squeezeUpdFrames;
 
-    rtsBool compact;
+    rtsBool compact;           /* True <=> "compact all the time" */
     double  compactThreshold;
 
     rtsBool ringBell;

diff --git a/ghc/rts/GC.c b/ghc/rts/GC.c
index 66d7d86..e0a665e 100644 (file)
--- a/ghc/rts/GC.c
+++ b/ghc/rts/GC.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.117 2001/08/08 13:45:02 simonmar Exp $
+ * $Id: GC.c,v 1.118 2001/08/08 14:14:08 simonmar Exp $
  *
  * (c) The GHC Team 1998-1999
  *
@@ -735,14 +735,28 @@ GarbageCollect ( void (*get_roots)(evac_fn), rtsBool force_major_gc )
                     RtsFlags.GcFlags.minOldGenSize);
 
       // minimum size for generation zero
-      min_alloc = (RtsFlags.GcFlags.pcFreeHeap * max) / 200;
+      min_alloc = stg_max((RtsFlags.GcFlags.pcFreeHeap * max) / 200,
+                         RtsFlags.GcFlags.minAllocAreaSize);
+
+      // Auto-enable compaction when the residency reaches a
+      // certain percentage of the maximum heap size (default: 30%).
+      if (RtsFlags.GcFlags.compact ||
+         (max > 0 &&
+          oldest_gen->steps[0].n_blocks > 
+          (RtsFlags.GcFlags.compactThreshold * max) / 100)) {
+         oldest_gen->steps[0].is_compacted = 1;
+//       fprintf(stderr,"compaction: on\n", live);
+      } else {
+         oldest_gen->steps[0].is_compacted = 0;
+//       fprintf(stderr,"compaction: off\n", live);
+      }
 
       // if we're going to go over the maximum heap size, reduce the
       // size of the generations accordingly.  The calculation is
       // different if compaction is turned on, because we don't need
       // to double the space required to collect the old generation.
       if (max != 0) {
-         if (RtsFlags.GcFlags.compact) {
+         if (oldest_gen->steps[0].is_compacted) {
              if ( (size + (size - 1) * (gens - 2) * 2) + min_alloc > max ) {
                  size = (max - min_alloc) / ((gens - 1) * 2 - 1);
              }
@@ -765,19 +779,6 @@ GarbageCollect ( void (*get_roots)(evac_fn), rtsBool force_major_gc )
       for (g = 0; g < gens; g++) {
          generations[g].max_blocks = size;
       }
-
-      // Auto-enable compaction when the residency reaches a
-      // certain percentage of the maximum heap size (default: 30%).
-      if (RtsFlags.GcFlags.compact &&
-         max > 0 && 
-         oldest_gen->steps[0].n_blocks > 
-           (RtsFlags.GcFlags.compactThreshold * max) / 100) {
-         oldest_gen->steps[0].is_compacted = 1;
-//       fprintf(stderr,"compaction: on\n", live);
-      } else {
-         oldest_gen->steps[0].is_compacted = 0;
-//       fprintf(stderr,"compaction: off\n", live);
-      }
   }
 
   // Guess the amount of live data for stats.

diff --git a/ghc/rts/RtsFlags.c b/ghc/rts/RtsFlags.c
index 5f6244e..3f44ccb 100644 (file)
--- a/ghc/rts/RtsFlags.c
+++ b/ghc/rts/RtsFlags.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: RtsFlags.c,v 1.45 2001/08/07 10:37:04 simonmar Exp $
+ * $Id: RtsFlags.c,v 1.46 2001/08/08 14:14:08 simonmar Exp $
  *
  * (c) The AQUA Project, Glasgow University, 1994-1997
  * (c) The GHC Team, 1998-1999
@@ -237,7 +237,7 @@ void initRtsFlagsDefaults(void)
     RtsFlags.GcFlags.steps              = 2;
     RtsFlags.GcFlags.squeezeUpdFrames  = rtsTrue;
 #endif
-    RtsFlags.GcFlags.compact            = rtsTrue;
+    RtsFlags.GcFlags.compact            = rtsFalse;
     RtsFlags.GcFlags.compactThreshold   = 30.0;
 #ifdef RTS_GTK_FRONTPANEL
     RtsFlags.GcFlags.frontpanel         = rtsFalse;
@@ -391,7 +391,7 @@ usage_text[] = {
 "  -T<n>    Number of steps in younger generations (default: 2)",
 "  -c<n>    Auto-enable compaction of the oldest generation when live data is",
 "           at least <n>% of the maximum heap size set with -M (default: 30%)",
-"  -c       Disable compaction",
+"  -c       Enable compaction for all major collections",
 "",
 "  -t<file> One-line GC statistics  (default file: <program>.stat)",
 "  -s<file> Summary  GC statistics  (with -Sstderr going to stderr)",
@@ -654,11 +654,10 @@ error = rtsTrue;
 
              case 'c':
                  if (rts_argv[arg][2] != '\0') {
-                     RtsFlags.GcFlags.compact = rtsTrue;
                      RtsFlags.GcFlags.compactThreshold =
                          atof(rts_argv[arg]+2);
                  } else {
-                     RtsFlags.GcFlags.compact = rtsFalse;
+                     RtsFlags.GcFlags.compact = rtsTrue;
                  }
                  break;
 

diff --git a/ghc/rts/Storage.c b/ghc/rts/Storage.c
index c98d2bf..51720d1 100644 (file)
--- a/ghc/rts/Storage.c
+++ b/ghc/rts/Storage.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Storage.c,v 1.45 2001/08/08 11:27:17 simonmar Exp $
+ * $Id: Storage.c,v 1.46 2001/08/08 14:14:08 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -162,7 +162,10 @@ initStorage( void )
     generations[g].steps[s].to = &generations[g+1].steps[0];
   }
   
-  /* The oldest generation has one step. */
+  /* The oldest generation has one step and it is compacted. */
+  if (RtsFlags.GcFlags.compact) {
+      oldest_gen->steps[0].is_compacted = 1;
+  }
   oldest_gen->steps[0].to = &oldest_gen->steps[0];
 
   /* generation 0 is special: that's the nursery */