From 4c47c22c37844784894dfadbf91d749fcafeef9d Mon Sep 17 00:00:00 2001
From: simonm <unknown>
Date: Fri, 5 Feb 1999 14:45:43 +0000
Subject: [PATCH] [project @ 1999-02-05 14:45:42 by simonm]
---
ghc/rts/GC.c | 140 ++++++++++++++++++++++++++++------------------
ghc/rts/Storage.c | 13 +++--
2 files changed, 96 insertions(+), 57 deletions(-)
diff --git a/ghc/rts/GC.c b/ghc/rts/GC.c
index a5abcd95e923..ffb58e9833bb 100644
--- a/ghc/rts/GC.c
+++ b/ghc/rts/GC.c
@@ -1,5 +1,5 @@
/* -----------------------------------------------------------------------------
- * $Id: GC.c,v 1.23 1999/02/02 14:21:29 simonm Exp $
+ * $Id: GC.c,v 1.24 1999/02/05 14:45:42 simonm Exp $
*
* Two-space garbage collector
*
@@ -103,8 +103,8 @@ static void scavenge_stack(StgPtr p, StgPtr stack_end);
static void scavenge_large(step *step);
static void scavenge(step *step);
static void scavenge_static(void);
-static StgMutClosure *scavenge_mutable_list(StgMutClosure *p, nat gen);
-static StgMutClosure *scavenge_mut_once_list(StgMutClosure *p, nat gen);
+static void scavenge_mutable_list(generation *g);
+static void scavenge_mut_once_list(generation *g);
#ifdef DEBUG
static void gcCAFs(void);
@@ -285,25 +285,27 @@ void GarbageCollect(void (*get_roots)(void))
* it has already been evaced to gen 2.
*/
{
- StgMutClosure *tmp, **pp;
- for (g = N+1; g < RtsFlags.GcFlags.generations; g++) {
+ int st;
+ for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
generations[g].saved_mut_list = generations[g].mut_list;
generations[g].mut_list = END_MUT_LIST;
}
/* Do the mut-once lists first */
for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
- generations[g].mut_once_list =
- scavenge_mut_once_list(generations[g].mut_once_list, g);
+ scavenge_mut_once_list(&generations[g]);
+ evac_gen = g;
+ for (st = generations[g].n_steps-1; st >= 0; st--) {
+ scavenge(&generations[g].steps[st]);
+ }
}
for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
- tmp = scavenge_mutable_list(generations[g].saved_mut_list, g);
- pp = &generations[g].mut_list;
- while (*pp != END_MUT_LIST) {
- pp = &(*pp)->mut_link;
+ scavenge_mutable_list(&generations[g]);
+ evac_gen = g;
+ for (st = generations[g].n_steps-1; st >= 0; st--) {
+ scavenge(&generations[g].steps[st]);
}
- *pp = tmp;
}
}
@@ -381,18 +383,21 @@ void GarbageCollect(void (*get_roots)(void))
/* scavenge each step in generations 0..maxgen */
{
- int gen;
+ int gen, st;
+ loop2:
for (gen = RtsFlags.GcFlags.generations-1; gen >= 0; gen--) {
- for (s = 0; s < generations[gen].n_steps; s++) {
- step = &generations[gen].steps[s];
+ for (st = generations[gen].n_steps-1; st >= 0 ; st--) {
+ step = &generations[gen].steps[st];
evac_gen = gen;
if (step->hp_bd != step->scan_bd || step->scan < step->hp) {
scavenge(step);
flag = rtsTrue;
+ goto loop2;
}
if (step->new_large_objects != NULL) {
scavenge_large(step);
flag = rtsTrue;
+ goto loop2;
}
}
}
@@ -1821,20 +1826,20 @@ scavenge_one(StgClosure *p)
remove non-mutable objects from the mutable list at this point.
-------------------------------------------------------------------------- */
-static StgMutClosure *
-scavenge_mut_once_list(StgMutClosure *p, nat gen)
+static void
+scavenge_mut_once_list(generation *gen)
{
StgInfoTable *info;
- StgMutClosure *start;
- StgMutClosure **prev;
+ StgMutClosure *p, *next, *new_list;
- prev = &start;
- start = p;
+ p = gen->mut_once_list;
+ new_list = END_MUT_LIST;
+ next = p->mut_link;
- evac_gen = gen;
+ evac_gen = gen->no;
failed_to_evac = rtsFalse;
- for (; p != END_MUT_LIST; p = *prev) {
+ for (; p != END_MUT_LIST; p = next, next = p->mut_link) {
/* make sure the info pointer is into text space */
ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
@@ -1852,6 +1857,31 @@ scavenge_mut_once_list(StgMutClosure *p, nat gen)
((StgIndOldGen *)p)->indirectee =
evacuate(((StgIndOldGen *)p)->indirectee);
+#if 0
+ /* Debugging code to print out the size of the thing we just
+ * promoted
+ */
+ {
+ StgPtr start = gen->steps[0].scan;
+ bdescr *start_bd = gen->steps[0].scan_bd;
+ nat size = 0;
+ scavenge(&gen->steps[0]);
+ if (start_bd != gen->steps[0].scan_bd) {
+ size += (P_)BLOCK_ROUND_UP(start) - start;
+ start_bd = start_bd->link;
+ while (start_bd != gen->steps[0].scan_bd) {
+ size += BLOCK_SIZE_W;
+ start_bd = start_bd->link;
+ }
+ size += gen->steps[0].scan -
+ (P_)BLOCK_ROUND_DOWN(gen->steps[0].scan);
+ } else {
+ size = gen->steps[0].scan - start;
+ }
+ fprintf(stderr,"evac IND_OLDGEN: %d bytes\n", size * sizeof(W_));
+ }
+#endif
+
/* failed_to_evac might happen if we've got more than two
* generations, we're collecting only generation 0, the
* indirection resides in generation 2 and the indirectee is
@@ -1859,9 +1889,9 @@ scavenge_mut_once_list(StgMutClosure *p, nat gen)
*/
if (failed_to_evac) {
failed_to_evac = rtsFalse;
- prev = &p->mut_link;
+ p->mut_link = new_list;
+ new_list = p;
} else {
- *prev = p->mut_link;
/* the mut_link field of an IND_STATIC is overloaded as the
* static link field too (it just so happens that we don't need
* both at the same time), so we need to NULL it out when
@@ -1880,13 +1910,12 @@ scavenge_mut_once_list(StgMutClosure *p, nat gen)
*/
ASSERT(p->header.info == &MUT_CONS_info);
if (scavenge_one(((StgMutVar *)p)->var) == rtsTrue) {
- /* didn't manage to promote everything, so leave the
- * MUT_CONS on the list.
+ /* didn't manage to promote everything, so put the
+ * MUT_CONS back on the list.
*/
- prev = &p->mut_link;
- } else {
- *prev = p->mut_link;
- }
+ p->mut_link = new_list;
+ new_list = p;
+ }
continue;
default:
@@ -1894,25 +1923,25 @@ scavenge_mut_once_list(StgMutClosure *p, nat gen)
barf("scavenge_mut_once_list: strange object?");
}
}
- return start;
+
+ gen->mut_once_list = new_list;
}
-static StgMutClosure *
-scavenge_mutable_list(StgMutClosure *p, nat gen)
+static void
+scavenge_mutable_list(generation *gen)
{
StgInfoTable *info;
- StgMutClosure *start;
- StgMutClosure **prev;
+ StgMutClosure *p, *next, *new_list;
- evac_gen = 0;
-
- prev = &start;
- start = p;
+ p = gen->saved_mut_list;
+ new_list = END_MUT_LIST;
+ next = p->mut_link;
+ evac_gen = 0;
failed_to_evac = rtsFalse;
- for (; p != END_MUT_LIST; p = *prev) {
+ for (; p != END_MUT_LIST; p = next, next = p->mut_link) {
/* make sure the info pointer is into text space */
ASSERT(p && (LOOKS_LIKE_GHC_INFO(GET_INFO(p))
@@ -1929,7 +1958,7 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
StgPtr end, q;
end = (P_)p + mut_arr_ptrs_sizeW((StgMutArrPtrs*)p);
- evac_gen = gen;
+ evac_gen = gen->no;
for (q = (P_)((StgMutArrPtrs *)p)->payload; q < end; q++) {
(StgClosure *)*q = evacuate((StgClosure *)*q);
}
@@ -1937,16 +1966,16 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
if (failed_to_evac) {
failed_to_evac = rtsFalse;
- prev = &p->mut_link;
- } else {
- *prev = p->mut_link;
- }
+ p->mut_link = new_list;
+ new_list = p;
+ }
continue;
}
case MUT_ARR_PTRS:
/* follow everything */
- prev = &p->mut_link;
+ p->mut_link = new_list;
+ new_list = p;
{
StgPtr end, q;
@@ -1964,7 +1993,8 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
*/
ASSERT(p->header.info != &MUT_CONS_info);
((StgMutVar *)p)->var = evacuate(((StgMutVar *)p)->var);
- prev = &p->mut_link;
+ p->mut_link = new_list;
+ new_list = p;
continue;
case MVAR:
@@ -1973,7 +2003,8 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
(StgClosure *)mvar->head = evacuate((StgClosure *)mvar->head);
(StgClosure *)mvar->tail = evacuate((StgClosure *)mvar->tail);
(StgClosure *)mvar->value = evacuate((StgClosure *)mvar->value);
- prev = &p->mut_link;
+ p->mut_link = new_list;
+ new_list = p;
continue;
}
@@ -1996,7 +2027,8 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
* point to some younger objects (because we set evac_gen to 0
* above).
*/
- prev = &tso->mut_link;
+ tso->mut_link = new_list;
+ new_list = (StgMutClosure *)tso;
continue;
}
@@ -2005,8 +2037,9 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
StgBlockingQueue *bh = (StgBlockingQueue *)p;
(StgClosure *)bh->blocking_queue =
evacuate((StgClosure *)bh->blocking_queue);
- prev = &p->mut_link;
- break;
+ p->mut_link = new_list;
+ new_list = p;
+ continue;
}
default:
@@ -2014,7 +2047,8 @@ scavenge_mutable_list(StgMutClosure *p, nat gen)
barf("scavenge_mut_list: strange object?");
}
}
- return start;
+
+ gen->mut_list = new_list;
}
static void
diff --git a/ghc/rts/Storage.c b/ghc/rts/Storage.c
index 2c8dc38dcdf7..88f890491024 100644
--- a/ghc/rts/Storage.c
+++ b/ghc/rts/Storage.c
@@ -1,5 +1,5 @@
/* -----------------------------------------------------------------------------
- * $Id: Storage.c,v 1.9 1999/02/02 14:21:33 simonm Exp $
+ * $Id: Storage.c,v 1.10 1999/02/05 14:45:43 simonm Exp $
*
* Storage manager front end
*
@@ -133,12 +133,17 @@ initStorage (void)
/* generation 0 is special: that's the nursery */
generations[0].max_blocks = 0;
- /* G0S0: the allocation area */
+ /* G0S0: the allocation area. Policy: keep the allocation area
+ * small to begin with, even if we have a large suggested heap
+ * size. Reason: we're going to do a major collection first, and we
+ * don't want it to be a big one. This vague idea is borne out by
+ * rigorous experimental evidence.
+ */
step = &generations[0].steps[0];
g0s0 = step;
- step->blocks = allocNursery(NULL, RtsFlags.GcFlags.minAllocAreaSize);
- step->n_blocks = RtsFlags.GcFlags.minAllocAreaSize;
nursery_blocks = RtsFlags.GcFlags.minAllocAreaSize;
+ step->blocks = allocNursery(NULL, nursery_blocks);
+ step->n_blocks = nursery_blocks;
current_nursery = step->blocks;
/* hp, hpLim, hp_bd, to_space etc. aren't used in G0S0 */
--
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