Specialise evac/scav for single-threaded, not minor, GC
[ghc-hetmet.git] / rts / sm / Scav.c
index 0f06ee9..e08572a 100644 (file)
@@ -134,6 +134,19 @@ scavenge_fun_srt(const StgInfoTable *info)
 static void
 scavengeTSO (StgTSO *tso)
 {
+    rtsBool saved_eager;
+
+    if (tso->what_next == ThreadRelocated) {
+        // the only way this can happen is if the old TSO was on the
+        // mutable list.  We might have other links to this defunct
+        // TSO, so we must update its link field.
+        evacuate((StgClosure**)&tso->_link);
+        return;
+    }
+
+    saved_eager = gct->eager_promotion;
+    gct->eager_promotion = rtsFalse;
+
     if (   tso->why_blocked == BlockedOnMVar
        || tso->why_blocked == BlockedOnBlackHole
        || tso->why_blocked == BlockedOnException
@@ -154,6 +167,14 @@ scavengeTSO (StgTSO *tso)
     
     // scavenge this thread's stack 
     scavenge_stack(tso->sp, &(tso->stack[tso->stack_size]));
+
+    if (gct->failed_to_evac) {
+        tso->flags |= TSO_DIRTY;
+    } else {
+        tso->flags &= ~TSO_DIRTY;
+    }
+
+    gct->eager_promotion = saved_eager;
 }
 
 /* -----------------------------------------------------------------------------
@@ -494,19 +515,7 @@ linear_scan:
 
        case TSO:
        { 
-           StgTSO *tso = (StgTSO *)p;
-           rtsBool saved_eager = gct->eager_promotion;
-
-           gct->eager_promotion = rtsFalse;
-           scavengeTSO(tso);
-           gct->eager_promotion = saved_eager;
-           
-           if (gct->failed_to_evac) {
-               tso->flags |= TSO_DIRTY;
-           } else {
-               tso->flags &= ~TSO_DIRTY;
-           }
-           
+            scavengeTSO((StgTSO*)p);
            gct->failed_to_evac = rtsTrue; // always on the mutable list
            break;
        }
@@ -826,19 +835,7 @@ scavenge_one(StgPtr p)
 
     case TSO:
     {
-       StgTSO *tso = (StgTSO *)p;
-       rtsBool saved_eager = gct->eager_promotion;
-
-       gct->eager_promotion = rtsFalse;
-       scavengeTSO(tso);
-       gct->eager_promotion = saved_eager;
-
-       if (gct->failed_to_evac) {
-           tso->flags |= TSO_DIRTY;
-       } else {
-           tso->flags &= ~TSO_DIRTY;
-       }
-
+       scavengeTSO((StgTSO*)p);
        gct->failed_to_evac = rtsTrue; // always on the mutable list
        break;
     }
@@ -1079,15 +1076,12 @@ scavenge_static(void)
 
   while (1) {
       
-    ACQUIRE_SPIN_LOCK(&static_objects_sync);
-    
     /* get the next static object from the list.  Remember, there might
      * be more stuff on this list after each evacuation...
      * (static_objects is a global)
      */
-    p = static_objects;
+    p = gct->static_objects;
     if (p == END_OF_STATIC_LIST) {
-         RELEASE_SPIN_LOCK(&static_objects_sync);
          break;
     }
     
@@ -1102,11 +1096,9 @@ scavenge_static(void)
     /* Take this object *off* the static_objects list,
      * and put it on the scavenged_static_objects list.
      */
-    static_objects = *STATIC_LINK(info,p);
-    *STATIC_LINK(info,p) = scavenged_static_objects;
-    scavenged_static_objects = p;
-    
-    RELEASE_SPIN_LOCK(&static_objects_sync);
+    gct->static_objects = *STATIC_LINK(info,p);
+    *STATIC_LINK(info,p) = gct->scavenged_static_objects;
+    gct->scavenged_static_objects = p;
     
     switch (info -> type) {
       
@@ -1391,9 +1383,9 @@ scavenge_large (step_workspace *ws)
    Scavenge a block
    ------------------------------------------------------------------------- */
 
-#define MINOR_GC
+#define PARALLEL_GC
 #include "Scav.c-inc"
-#undef MINOR_GC
+#undef PARALLEL_GC
 #include "Scav.c-inc"
 
 /* ----------------------------------------------------------------------------
@@ -1404,40 +1396,41 @@ static rtsBool
 scavenge_find_global_work (void)
 {
     bdescr *bd;
-    int g, s;
+    int s;
     rtsBool flag;
     step_workspace *ws;
 
+    gct->scav_global_work++;
+
     flag = rtsFalse;
-    for (g = RtsFlags.GcFlags.generations-1; g >= 0; g--) {
-       for (s = generations[g].n_steps-1; s >= 0; s--) {
-           if (g == 0 && s == 0 && RtsFlags.GcFlags.generations > 1) { 
-               continue; 
-           }
-           ws = &gct->steps[g][s];
+    for (s = total_steps-1; s>=0; s--)
+    {
+        if (s == 0 && RtsFlags.GcFlags.generations > 1) { 
+            continue; 
+        }
+        ws = &gct->steps[s];
 
-           // If we have any large objects to scavenge, do them now.
-           if (ws->todo_large_objects) {
-               scavenge_large(ws);
-               flag = rtsTrue;
-           }
+        // If we have any large objects to scavenge, do them now.
+        if (ws->todo_large_objects) {
+            scavenge_large(ws);
+            flag = rtsTrue;
+        }
 
-           if ((bd = grab_todo_block(ws)) != NULL) {
-               // no need to assign this to ws->scan_bd, we're going
-               // to scavenge the whole thing and then push it on
-               // our scavd list.  This saves pushing out the
-               // scan_bd block, which might be partial.
-               if (N == 0) {
-                   scavenge_block0(bd, bd->start);
-               } else {
-                   scavenge_block(bd, bd->start);
-               }
-               push_scan_block(bd, ws);
-               return rtsTrue;
-           }
+        if ((bd = grab_todo_block(ws)) != NULL) {
+            // no need to assign this to ws->scan_bd, we're going
+            // to scavenge the whole thing and then push it on
+            // our scavd list.  This saves pushing out the
+            // scan_bd block, which might be partial.
+            if (n_gc_threads == 1) {
+                scavenge_block1(bd, bd->start);
+            } else {
+                scavenge_block(bd, bd->start);
+            }
+            push_scan_block(bd, ws);
+            return rtsTrue;
+        }
 
-           if (flag) return rtsTrue;
-       }
+        if (flag) return rtsTrue;
     }
     return rtsFalse;
 }
@@ -1457,60 +1450,60 @@ scavenge_find_global_work (void)
 static rtsBool
 scavenge_find_local_work (void)
 {
-    int g, s;
+    int s;
     step_workspace *ws;
     rtsBool flag;
 
+    gct->scav_local_work++;
+
     flag = rtsFalse;
-    for (g = RtsFlags.GcFlags.generations; --g >= 0; ) {
-       for (s = generations[g].n_steps; --s >= 0; ) {
-           if (g == 0 && s == 0 && RtsFlags.GcFlags.generations > 1) { 
-               continue; 
-           }
-           ws = &gct->steps[g][s];
+    for (s = total_steps-1; s >= 0; s--) {
+        if (s == 0 && RtsFlags.GcFlags.generations > 1) { 
+            continue; 
+        }
+        ws = &gct->steps[s];
 
-            if (ws->todo_bd != NULL)
-            {
-                ws->todo_bd->free = ws->todo_free;
+        if (ws->todo_bd != NULL)
+        {
+            ws->todo_bd->free = ws->todo_free;
+        }
+        
+        // If we have a todo block and no scan block, start
+        // scanning the todo block.
+        if (ws->scan_bd == NULL && ws->todo_bd != NULL)
+        {
+            ws->scan_bd = ws->todo_bd;
+            ws->scan = ws->scan_bd->start;
+        }
+        
+        // If we have a scan block with some work to do,
+        // scavenge everything up to the free pointer.
+        if (ws->scan != NULL && ws->scan < ws->scan_bd->free)
+        {
+            if (n_gc_threads == 1) {
+                scavenge_block1(ws->scan_bd, ws->scan);
+            } else {
+                scavenge_block(ws->scan_bd, ws->scan);
             }
-
-           // If we have a todo block and no scan block, start
-           // scanning the todo block.
-           if (ws->scan_bd == NULL && ws->todo_bd != NULL)
-           {
-               ws->scan_bd = ws->todo_bd;
-               ws->scan = ws->scan_bd->start;
-           }
-
-           // If we have a scan block with some work to do,
-           // scavenge everything up to the free pointer.
-           if (ws->scan != NULL && ws->scan < ws->scan_bd->free)
-           {
-               if (N == 0) {
-                   scavenge_block0(ws->scan_bd, ws->scan);
-               } else {
-                   scavenge_block(ws->scan_bd, ws->scan);
-               }
-               ws->scan = ws->scan_bd->free;
-               flag = rtsTrue;
-           }
-
-           if (ws->scan_bd != NULL && ws->scan == ws->scan_bd->free
-               && ws->scan_bd != ws->todo_bd)
-           {
-               // we're not going to evac any more objects into
-               // this block, so push it now.
-               push_scan_block(ws->scan_bd, ws);
-               ws->scan_bd = NULL;
-               ws->scan = NULL;
-                // we might be able to scan the todo block now.  But
-                // don't do it right away: there might be full blocks
-               // waiting to be scanned as a result of scavenge_block above.
-               flag = rtsTrue; 
-           }
-
-           if (flag) return rtsTrue;
-       }
+            ws->scan = ws->scan_bd->free;
+            flag = rtsTrue;
+        }
+        
+        if (ws->scan_bd != NULL && ws->scan == ws->scan_bd->free
+            && ws->scan_bd != ws->todo_bd)
+        {
+            // we're not going to evac any more objects into
+            // this block, so push it now.
+            push_scan_block(ws->scan_bd, ws);
+            ws->scan_bd = NULL;
+            ws->scan = NULL;
+            // we might be able to scan the todo block now.  But
+            // don't do it right away: there might be full blocks
+            // waiting to be scanned as a result of scavenge_block above.
+            flag = rtsTrue; 
+        }
+        
+        if (flag) return rtsTrue;
     }
     return rtsFalse;
 }
@@ -1528,8 +1521,8 @@ loop:
     work_to_do = rtsFalse;
 
     // scavenge static objects 
-    if (major_gc && static_objects != END_OF_STATIC_LIST) {
-       IF_DEBUG(sanity, checkStaticObjects(static_objects));
+    if (major_gc && gct->static_objects != END_OF_STATIC_LIST) {
+       IF_DEBUG(sanity, checkStaticObjects(gct->static_objects));
        scavenge_static();
     }
     
@@ -1554,16 +1547,13 @@ loop:
 rtsBool
 any_work (void)
 {
-    int g, s;
+    int s;
     step_workspace *ws;
 
+    gct->any_work++;
+
     write_barrier();
 
-    // scavenge static objects 
-    if (major_gc && static_objects != END_OF_STATIC_LIST) {
-       return rtsTrue;
-    }
-    
     // scavenge objects in compacted generation
     if (mark_stack_overflowed || oldgen_scan_bd != NULL ||
        (mark_stack_bdescr != NULL && !mark_stack_empty())) {
@@ -1573,16 +1563,16 @@ any_work (void)
     // Check for global work in any step.  We don't need to check for
     // local work, because we have already exited scavenge_loop(),
     // which means there is no local work for this thread.
-    for (g = RtsFlags.GcFlags.generations-1; g >= 0; g--) {
-       for (s = generations[g].n_steps-1; s >= 0; s--) {
-           if (g == 0 && s == 0 && RtsFlags.GcFlags.generations > 1) { 
-               continue; 
-           }
-           ws = &gct->steps[g][s];
-           if (ws->todo_large_objects) return rtsTrue;
-           if (ws->stp->todos) return rtsTrue;
-       }
+    for (s = total_steps-1; s >= 0; s--) {
+        if (s == 0 && RtsFlags.GcFlags.generations > 1) { 
+            continue; 
+        }
+        ws = &gct->steps[s];
+        if (ws->todo_large_objects) return rtsTrue;
+        if (ws->stp->todos) return rtsTrue;
     }
 
+    gct->no_work++;
+
     return rtsFalse;
 }