Allow work units smaller than a block to improve load balancing

[ghc-hetmet.git] / rts / sm / GC.c

diff --git a/rts/sm/GC.c b/rts/sm/GC.c
index 94da824..a361175 100644 (file)
--- a/rts/sm/GC.c
+++ b/rts/sm/GC.c
@@ -422,22 +422,34 @@ GarbageCollect ( rtsBool force_major_gc )
               ws = &thr->steps[s];
               // Not true?
               // ASSERT( ws->scan_bd == ws->todo_bd );
-              ASSERT( ws->scan_bd ? ws->scan == ws->scan_bd->free : 1 );
+              ASSERT( ws->scan_bd ? ws->scan_bd->u.scan == ws->scan_bd->free : 1 );
 
               // Push the final block
-              if (ws->scan_bd) { push_scan_block(ws->scan_bd, ws); }
+              if (ws->scan_bd) { push_scanned_block(ws->scan_bd, ws); }
               
               ASSERT(countBlocks(ws->scavd_list) == ws->n_scavd_blocks);
               
-              prev = ws->scavd_list;
+              prev = ws->part_list;
+              for (bd = ws->part_list; bd != NULL; bd = bd->link) {
+                  bd->flags &= ~BF_EVACUATED;   // now from-space 
+                  prev = bd;
+              }
+              if (prev != NULL) {
+                  prev->link = ws->scavd_list;
+              }
               for (bd = ws->scavd_list; bd != NULL; bd = bd->link) {
                   bd->flags &= ~BF_EVACUATED;   // now from-space 
                   prev = bd;
               }
-              prev->link = ws->stp->blocks;
-              ws->stp->blocks = ws->scavd_list;
-              ws->stp->n_blocks += ws->n_scavd_blocks;
-              ASSERT(countBlocks(ws->stp->blocks) == ws->stp->n_blocks);
+              prev->link = ws->step->blocks;
+              if (ws->part_list != NULL) {
+                  ws->step->blocks = ws->part_list;
+              } else {
+                  ws->step->blocks = ws->scavd_list;
+              }
+              ws->step->n_blocks += ws->n_part_blocks;
+              ws->step->n_blocks += ws->n_scavd_blocks;
+              ASSERT(countBlocks(ws->step->blocks) == ws->step->n_blocks);
          }
       }
   }
@@ -461,13 +473,12 @@ GarbageCollect ( rtsBool force_major_gc )
   { 
       nat i;
       for (i=0; i < n_gc_threads; i++) {
-          if (major_gc) {
+          if (n_gc_threads > 1) {
               trace(TRACE_gc,"thread %d:", i);
               trace(TRACE_gc,"   copied           %ld", gc_threads[i]->copied * sizeof(W_));
               trace(TRACE_gc,"   any_work         %ld", gc_threads[i]->any_work);
               trace(TRACE_gc,"   no_work          %ld", gc_threads[i]->no_work);
-              trace(TRACE_gc,"   scav_global_work %ld", gc_threads[i]->scav_global_work);
-              trace(TRACE_gc,"   scav_local_work  %ld", gc_threads[i]->scav_local_work);
+              trace(TRACE_gc,"   scav_find_work %ld",   gc_threads[i]->scav_find_work);
           }
           copied += gc_threads[i]->copied;
       }
@@ -982,16 +993,18 @@ alloc_gc_thread (int n)
     for (s = 0; s < total_steps; s++)
     {
         ws = &t->steps[s];
-        ws->stp = &all_steps[s];
-        ASSERT(s == ws->stp->abs_no);
+        ws->step = &all_steps[s];
+        ASSERT(s == ws->step->abs_no);
         ws->gct = t;
         
         ws->scan_bd = NULL;
-        ws->scan = NULL;
 
         ws->todo_bd = NULL;
         ws->buffer_todo_bd = NULL;
         
+        ws->part_list = NULL;
+        ws->n_part_blocks = 0;
+
         ws->scavd_list = NULL;
         ws->n_scavd_blocks = 0;
     }
@@ -1305,15 +1318,17 @@ init_collected_gen (nat g, nat n_threads)
            ws = &gc_threads[t]->steps[g * RtsFlags.GcFlags.steps + s];
 
            ws->scan_bd = NULL;
-           ws->scan = NULL;
 
            ws->todo_large_objects = NULL;
 
+            ws->part_list = NULL;
+            ws->n_part_blocks = 0;
+
            // allocate the first to-space block; extra blocks will be
            // chained on as necessary.
            ws->todo_bd = NULL;
            ws->buffer_todo_bd = NULL;
-           gc_alloc_todo_block(ws);
+           alloc_todo_block(ws,0);
 
            ws->scavd_list = NULL;
            ws->n_scavd_blocks = 0;
@@ -1344,11 +1359,14 @@ init_uncollected_gen (nat g, nat threads)
        for (s = 0; s < generations[g].n_steps; s++) {
            
            ws = &gc_threads[t]->steps[g * RtsFlags.GcFlags.steps + s];
-           stp = ws->stp;
+           stp = ws->step;
            
            ws->buffer_todo_bd = NULL;
            ws->todo_large_objects = NULL;
 
+            ws->part_list = NULL;
+            ws->n_part_blocks = 0;
+
            ws->scavd_list = NULL;
            ws->n_scavd_blocks = 0;
 
@@ -1366,7 +1384,7 @@ init_uncollected_gen (nat g, nat threads)
                // this block is also the scan block; we must scan
                // from the current end point.
                ws->scan_bd = ws->todo_bd;
-               ws->scan = ws->scan_bd->free;
+               ws->scan_bd->u.scan = ws->scan_bd->free;
 
                // subtract the contents of this block from the stats,
                // because we'll count the whole block later.
@@ -1375,9 +1393,8 @@ init_uncollected_gen (nat g, nat threads)
            else
            {
                ws->scan_bd = NULL;
-               ws->scan = NULL;
                ws->todo_bd = NULL;
-               gc_alloc_todo_block(ws);
+               alloc_todo_block(ws,0);
            }
        }
     }
@@ -1411,8 +1428,7 @@ init_gc_thread (gc_thread *t)
     t->copied = 0;
     t->any_work = 0;
     t->no_work = 0;
-    t->scav_global_work = 0;
-    t->scav_local_work = 0;
+    t->scav_find_work = 0;
 
 }