/* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.20 1999/01/26 16:16:22 simonm Exp $
+ * $Id: GC.c,v 1.21 1999/01/27 16:41:14 simonm Exp $
*
* Two-space garbage collector
*
}
}
}
- } else {
- /* For a two-space collector, we need to resize the nursery. */
-
- /* set up a new nursery. Allocate a nursery size based on a
- * function of the amount of live data (currently a factor of 2,
- * should be configurable (ToDo)). Use the blocks from the old
- * nursery if possible, freeing up any left over blocks.
- *
- * If we get near the maximum heap size, then adjust our nursery
- * size accordingly. If the nursery is the same size as the live
- * data (L), then we need 3L bytes. We can reduce the size of the
- * nursery to bring the required memory down near 2L bytes.
- *
- * A normal 2-space collector would need 4L bytes to give the same
- * performance we get from 3L bytes, reducing to the same
- * performance at 2L bytes.
- */
- nat blocks = g0s0->to_blocks;
-
- if ( blocks * RtsFlags.GcFlags.oldGenFactor * 2 >
- RtsFlags.GcFlags.maxHeapSize ) {
- int adjusted_blocks; /* signed on purpose */
- int pc_free;
-
- adjusted_blocks = (RtsFlags.GcFlags.maxHeapSize - 2 * blocks);
- IF_DEBUG(gc, fprintf(stderr, "Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %d\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks));
- pc_free = adjusted_blocks * 100 / RtsFlags.GcFlags.maxHeapSize;
- if (pc_free < RtsFlags.GcFlags.pcFreeHeap) /* might even be < 0 */ {
- heapOverflow();
- }
- blocks = adjusted_blocks;
-
- } else {
- blocks *= RtsFlags.GcFlags.oldGenFactor;
- if (blocks < RtsFlags.GcFlags.minAllocAreaSize) {
- blocks = RtsFlags.GcFlags.minAllocAreaSize;
- }
- }
-
- if (nursery_blocks < blocks) {
- IF_DEBUG(gc, fprintf(stderr, "Increasing size of nursery to %d blocks\n",
- blocks));
- g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
- } else {
- bdescr *next_bd;
-
- IF_DEBUG(gc, fprintf(stderr, "Decreasing size of nursery to %d blocks\n",
- blocks));
- for (bd = g0s0->blocks; nursery_blocks > blocks; nursery_blocks--) {
- next_bd = bd->link;
- freeGroup(bd);
- bd = next_bd;
- }
- g0s0->blocks = bd;
- }
-
- g0s0->n_blocks = nursery_blocks = blocks;
}
/* run through all the generations/steps and tidy up
* between the maximum size of the oldest and youngest
* generations.
*
- * max_blocks = alloc_area_size +
- * (oldgen_max_blocks - alloc_area_size) * G
- * -----------------------------------------
- * oldest_gen
+ * max_blocks = oldgen_max_blocks * G
+ * ----------------------
+ * oldest_gen
*/
if (g != 0) {
- generations[g].max_blocks =
- RtsFlags.GcFlags.minAllocAreaSize +
- (((oldest_gen->max_blocks - RtsFlags.GcFlags.minAllocAreaSize) * g)
- / (RtsFlags.GcFlags.generations-1));
+ generations[g].max_blocks = (oldest_gen->max_blocks * g)
+ / (RtsFlags.GcFlags.generations-1);
}
/* for older generations... */
* Free the old to-space, and estimate the amount of live data.
*/
if (RtsFlags.GcFlags.generations == 1) {
+ nat blocks;
+
if (old_to_space != NULL) {
freeChain(old_to_space);
}
live = g0s0->to_blocks * BLOCK_SIZE_W +
((lnat)g0s0->hp_bd->free - (lnat)g0s0->hp_bd->start) / sizeof(W_);
- /* Generational collector:
- * estimate the amount of live data.
- */
+ /* For a two-space collector, we need to resize the nursery. */
+
+ /* set up a new nursery. Allocate a nursery size based on a
+ * function of the amount of live data (currently a factor of 2,
+ * should be configurable (ToDo)). Use the blocks from the old
+ * nursery if possible, freeing up any left over blocks.
+ *
+ * If we get near the maximum heap size, then adjust our nursery
+ * size accordingly. If the nursery is the same size as the live
+ * data (L), then we need 3L bytes. We can reduce the size of the
+ * nursery to bring the required memory down near 2L bytes.
+ *
+ * A normal 2-space collector would need 4L bytes to give the same
+ * performance we get from 3L bytes, reducing to the same
+ * performance at 2L bytes.
+ */
+ blocks = g0s0->n_blocks;
+
+ if ( blocks * RtsFlags.GcFlags.oldGenFactor * 2 >
+ RtsFlags.GcFlags.maxHeapSize ) {
+ int adjusted_blocks; /* signed on purpose */
+ int pc_free;
+
+ adjusted_blocks = (RtsFlags.GcFlags.maxHeapSize - 2 * blocks);
+ IF_DEBUG(gc, fprintf(stderr, "Near maximum heap size of 0x%x blocks, blocks = %d, adjusted to %d\n", RtsFlags.GcFlags.maxHeapSize, blocks, adjusted_blocks));
+ pc_free = adjusted_blocks * 100 / RtsFlags.GcFlags.maxHeapSize;
+ if (pc_free < RtsFlags.GcFlags.pcFreeHeap) /* might even be < 0 */ {
+ heapOverflow();
+ }
+ blocks = adjusted_blocks;
+
+ } else {
+ blocks *= RtsFlags.GcFlags.oldGenFactor;
+ if (blocks < RtsFlags.GcFlags.minAllocAreaSize) {
+ blocks = RtsFlags.GcFlags.minAllocAreaSize;
+ }
+ }
+
+ if (nursery_blocks < blocks) {
+ IF_DEBUG(gc, fprintf(stderr, "Increasing size of nursery to %d blocks\n",
+ blocks));
+ g0s0->blocks = allocNursery(g0s0->blocks, blocks-nursery_blocks);
+ } else {
+ bdescr *next_bd;
+
+ IF_DEBUG(gc, fprintf(stderr, "Decreasing size of nursery to %d blocks\n",
+ blocks));
+ for (bd = g0s0->blocks; nursery_blocks > blocks; nursery_blocks--) {
+ next_bd = bd->link;
+ freeGroup(bd);
+ bd = next_bd;
+ }
+ g0s0->blocks = bd;
+ }
+
+ g0s0->n_blocks = nursery_blocks = blocks;
+
} else {
+ /* Generational collector:
+ * estimate the amount of live data, and adjust the allocation
+ * area size if the user has given us a suggestion (+RTS -H<blah>)
+ */
+
live = 0;
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
for (s = 0; s < generations[g].n_steps; s++) {
((lnat)step->hp_bd->free -(lnat)step->hp_bd->start) / sizeof(W_);
}
}
+
+ if (RtsFlags.GcFlags.heapSizeSuggestion) {
+ nat avail_blocks =
+ (RtsFlags.GcFlags.heapSizeSuggestion - live / BLOCK_SIZE_W) / 2;
+ nat blocks;
+
+ if (avail_blocks > RtsFlags.GcFlags.minAllocAreaSize) {
+ blocks = avail_blocks;
+ } else {
+ blocks = RtsFlags.GcFlags.minAllocAreaSize;
+ }
+
+ if (blocks > g0s0->n_blocks) {
+ /* need to add some blocks on */
+ fprintf(stderr, "Increasing size of alloc area to %d blocks\n", blocks);
+ g0s0->blocks = allocNursery(g0s0->blocks, avail_blocks - g0s0->n_blocks);
+ } else {
+ bdescr *next_bd;
+ fprintf(stderr, "Decreasing size of alloc area to %d blocks\n", blocks);
+ for (bd = g0s0->blocks; nursery_blocks > blocks; nursery_blocks--) {
+ next_bd = bd->link;
+ freeGroup(bd);
+ bd = next_bd;
+ }
+ g0s0->blocks = bd;
+ }
+ g0s0->n_blocks = nursery_blocks = blocks;
+ }
}
/* revert dead CAFs and update enteredCAFs list */
projects / ghc-hetmet.git / blobdiff