X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2Fsm%2FGCUtils.c;h=57cede7d43390dc4605404792b1d212278e61fd6;hb=c36ca010c5f7e019c9dd4d122be5c22905777e38;hp=634106756572bc57f1096d64e584f71e74df46ec;hpb=02038ff3db11048d90f59b9c05bc188180e0db39;p=ghc-hetmet.git

diff --git a/rts/sm/GCUtils.c b/rts/sm/GCUtils.c
index 6341067..57cede7 100644
--- a/rts/sm/GCUtils.c
+++ b/rts/sm/GCUtils.c
@@ -1,6 +1,6 @@
 /* -----------------------------------------------------------------------------
  *
- * (c) The GHC Team 1998-2006
+ * (c) The GHC Team 1998-2008
  *
  * Generational garbage collector: utilities
  *
@@ -15,9 +15,13 @@
 #include "RtsFlags.h"
 #include "Storage.h"
 #include "GC.h"
+#include "GCThread.h"
 #include "GCUtils.h"
 #include "Printer.h"
 #include "Trace.h"
+#ifdef THREADED_RTS
+#include "WSDeque.h"
+#endif
 
 #ifdef THREADED_RTS
 SpinLock gc_alloc_block_sync;
@@ -33,107 +37,235 @@ allocBlock_sync(void)
     return bd;
 }
 
+
+#if 0
+static void
+allocBlocks_sync(nat n, bdescr **hd, bdescr **tl, 
+                 nat gen_no, step *stp,
+                 StgWord32 flags)
+{
+    bdescr *bd;
+    nat i;
+    ACQUIRE_SPIN_LOCK(&gc_alloc_block_sync);
+    bd = allocGroup(n);
+    for (i = 0; i < n; i++) {
+        bd[i].blocks = 1;
+        bd[i].gen_no = gen_no;
+        bd[i].step = stp;
+        bd[i].flags = flags;
+        bd[i].link = &bd[i+1];
+        bd[i].u.scan = bd[i].free = bd[i].start;
+    }
+    *hd = bd;
+    *tl = &bd[n-1];
+    RELEASE_SPIN_LOCK(&gc_alloc_block_sync);
+}
+#endif
+
+void
+freeChain_sync(bdescr *bd)
+{
+    ACQUIRE_SPIN_LOCK(&gc_alloc_block_sync);
+    freeChain(bd);
+    RELEASE_SPIN_LOCK(&gc_alloc_block_sync);
+}
+
 /* -----------------------------------------------------------------------------
    Workspace utilities
    -------------------------------------------------------------------------- */
 
 bdescr *
-grab_todo_block (step_workspace *ws)
+grab_local_todo_block (step_workspace *ws)
 {
     bdescr *bd;
     step *stp;
 
-    stp = ws->stp;
-    bd = NULL;
+    stp = ws->step;
+
+    bd = ws->todo_overflow;
+    if (bd != NULL)
+    {
+        ws->todo_overflow = bd->link;
+        bd->link = NULL;
+        ws->n_todo_overflow--;
+	return bd;
+    }
 
-    if (ws->buffer_todo_bd)
+    bd = popWSDeque(ws->todo_q);
+    if (bd != NULL)
     {
-	bd = ws->buffer_todo_bd;
 	ASSERT(bd->link == NULL);
-	ws->buffer_todo_bd = NULL;
 	return bd;
     }
 
-    ACQUIRE_SPIN_LOCK(&stp->sync_todo);
-    if (stp->todos) {
-	bd = stp->todos;
-	stp->todos = bd->link;
-        stp->n_todos--;
-	bd->link = NULL;
-    }	
-    RELEASE_SPIN_LOCK(&stp->sync_todo);
-    return bd;
+    return NULL;
 }
 
-static void
-push_todo_block (bdescr *bd, step *stp)
+bdescr *
+steal_todo_block (nat s)
 {
-    ASSERT(bd->link == NULL);
-    ACQUIRE_SPIN_LOCK(&stp->sync_todo);
-    bd->link = stp->todos;
-    stp->todos = bd;
-    stp->n_todos++;
-    trace(TRACE_gc, "step %d, n_todos: %d", stp->abs_no, stp->n_todos);
-    RELEASE_SPIN_LOCK(&stp->sync_todo);
+    nat n;
+    bdescr *bd;
+
+    // look for work to steal
+    for (n = 0; n < n_gc_threads; n++) {
+        if (n == gct->thread_index) continue;
+        bd = stealWSDeque(gc_threads[n]->steps[s].todo_q);
+        if (bd) {
+            return bd;
+        }
+    }
+    return NULL;
 }
 
 void
-push_scan_block (bdescr *bd, step_workspace *ws)
+push_scanned_block (bdescr *bd, step_workspace *ws)
 {
     ASSERT(bd != NULL);
     ASSERT(bd->link == NULL);
+    ASSERT(bd->step == ws->step);
+    ASSERT(bd->u.scan == bd->free);
 
-    // update stats: this is a block that has been copied & scavenged
-    copied += bd->free - bd->start;
+    if (bd->start + BLOCK_SIZE_W - bd->free > WORK_UNIT_WORDS)
+    {
+        // a partially full block: put it on the part_list list.
+        bd->link = ws->part_list;
+        ws->part_list = bd;
+        ws->n_part_blocks++;
+        IF_DEBUG(sanity, 
+                 ASSERT(countBlocks(ws->part_list) == ws->n_part_blocks));
+    }
+    else
+    {
+        // put the scan block on the ws->scavd_list.
+        bd->link = ws->scavd_list;
+        ws->scavd_list = bd;
+        ws->n_scavd_blocks ++;
+        IF_DEBUG(sanity, 
+                 ASSERT(countBlocks(ws->scavd_list) == ws->n_scavd_blocks));
+    }
+}
 
-    // put the scan block on the ws->scavd_list.
-    bd->link = ws->scavd_list;
-    ws->scavd_list = bd;
-    ws->n_scavd_blocks ++;
+StgPtr
+todo_block_full (nat size, step_workspace *ws)
+{
+    StgPtr p;
+    bdescr *bd;
+
+    // todo_free has been pre-incremented by Evac.c:alloc_for_copy().  We
+    // are expected to leave it bumped when we've finished here.
+    ws->todo_free -= size;
+
+    bd = ws->todo_bd;
+
+    ASSERT(bd != NULL);
+    ASSERT(bd->link == NULL);
+    ASSERT(bd->step == ws->step);
+
+    // If the global list is not empty, or there's not much work in
+    // this block to push, and there's enough room in
+    // this block to evacuate the current object, then just increase
+    // the limit.
+    if (!looksEmptyWSDeque(ws->todo_q) || 
+        (ws->todo_free - bd->u.scan < WORK_UNIT_WORDS / 2)) {
+        if (ws->todo_free + size < bd->start + BLOCK_SIZE_W) {
+            ws->todo_lim = stg_min(bd->start + BLOCK_SIZE_W,
+                                   ws->todo_lim + stg_max(WORK_UNIT_WORDS,size));
+            debugTrace(DEBUG_gc, "increasing limit for %p to %p", bd->start, ws->todo_lim);
+            p = ws->todo_free;
+            ws->todo_free += size;
+            return p;
+        }
+    }
+    
+    gct->copied += ws->todo_free - bd->free;
+    bd->free = ws->todo_free;
 
-    IF_DEBUG(sanity, 
-	     ASSERT(countBlocks(ws->scavd_list) == ws->n_scavd_blocks));
+    ASSERT(bd->u.scan >= bd->start && bd->u.scan <= bd->free);
+
+    // If this block is not the scan block, we want to push it out and
+    // make room for a new todo block.
+    if (bd != gct->scan_bd)
+    {
+        // If this block does not have enough space to allocate the
+        // current object, but it also doesn't have any work to push, then 
+        // push it on to the scanned list.  It cannot be empty, because
+        // then there would be enough room to copy the current object.
+        if (bd->u.scan == bd->free)
+        {
+            ASSERT(bd->free != bd->start);
+            push_scanned_block(bd, ws);
+        }
+        // Otherwise, push this block out to the global list.
+        else 
+        {
+            step *stp;
+            stp = ws->step;
+            debugTrace(DEBUG_gc, "push todo block %p (%ld words), step %d, todo_q: %ld", 
+                  bd->start, (unsigned long)(bd->free - bd->u.scan),
+                  stp->abs_no, dequeElements(ws->todo_q));
+
+            if (!pushWSDeque(ws->todo_q, bd)) {
+                bd->link = ws->todo_overflow;
+                ws->todo_overflow = bd;
+                ws->n_todo_overflow++;
+            }
+        }
+    }
+
+    ws->todo_bd   = NULL;
+    ws->todo_free = NULL;
+    ws->todo_lim  = NULL;
+
+    alloc_todo_block(ws, size);
+
+    p = ws->todo_free;
+    ws->todo_free += size;
+    return p;
 }
 
 StgPtr
-gc_alloc_todo_block (step_workspace *ws)
+alloc_todo_block (step_workspace *ws, nat size)
 {
-    bdescr *bd;
+    bdescr *bd/*, *hd, *tl */;
 
-    if (ws->todo_bd != NULL) {
-        ws->todo_bd->free = ws->todo_free;
+    // Grab a part block if we have one, and it has enough room
+    if (ws->part_list != NULL && 
+        ws->part_list->start + BLOCK_SIZE_W - ws->part_list->free > (int)size)
+    {
+        bd = ws->part_list;
+        ws->part_list = bd->link;
+        ws->n_part_blocks--;
     }
+    else
+    {
+        // blocks in to-space get the BF_EVACUATED flag.
 
-    // If we already have a todo block, it must be full, so we push it
-    // out: first to the buffer_todo_bd, then to the step.  BUT, don't
-    // push out the block out if it is already the scan block.
-    if (ws->todo_bd != NULL && ws->scan_bd != ws->todo_bd) {
-	ASSERT(ws->todo_bd->link == NULL);
-	if (ws->buffer_todo_bd != NULL) {
-	    ASSERT(ws->buffer_todo_bd->link == NULL);
-	    push_todo_block(ws->buffer_todo_bd, ws->stp);
-	}
-	ws->buffer_todo_bd = ws->todo_bd;
-	ws->todo_bd = NULL;
-    }	    
+//        allocBlocks_sync(16, &hd, &tl, 
+//                         ws->step->gen_no, ws->step, BF_EVACUATED);
+//
+//        tl->link = ws->part_list;
+//        ws->part_list = hd->link;
+//        ws->n_part_blocks += 15;
+//
+//        bd = hd;
 
-    bd = allocBlock_sync();
+        bd = allocBlock_sync();
+        bd->step = ws->step;
+        bd->gen_no = ws->step->gen_no;
+        bd->flags = BF_EVACUATED;
+        bd->u.scan = bd->free = bd->start;
+    }
 
-    bd->gen_no = ws->stp->gen_no;
-    bd->step = ws->stp;
     bd->link = NULL;
 
-    // blocks in to-space in generations up to and including N
-    // get the BF_EVACUATED flag.
-    if (ws->stp->gen_no <= N) {
-	bd->flags = BF_EVACUATED;
-    } else {
-	bd->flags = 0;
-    }
-	
     ws->todo_bd = bd;
-    ws->todo_free = bd->start;
-    ws->todo_lim  = bd->start + BLOCK_SIZE_W;
+    ws->todo_free = bd->free;
+    ws->todo_lim  = stg_min(bd->start + BLOCK_SIZE_W,
+                            bd->free + stg_max(WORK_UNIT_WORDS,size));
+
+    debugTrace(DEBUG_gc, "alloc new todo block %p for step %d", 
+               bd->free, ws->step->abs_no);
 
     return ws->todo_free;
 }