#include "GC.h"
#include "GCThread.h"
+#include "GCTDecl.h"
#include "Compact.h"
#include "Evac.h"
#include "Scav.h"
static void mark_root (void *user, StgClosure **root);
static void zero_static_object_list (StgClosure* first_static);
static nat initialise_N (rtsBool force_major_gc);
-static void init_collected_gen (nat g, nat threads);
-static void init_uncollected_gen (nat g, nat threads);
+static void prepare_collected_gen (generation *gen);
+static void prepare_uncollected_gen (generation *gen);
static void init_gc_thread (gc_thread *t);
static void resize_generations (void);
static void resize_nursery (void);
static void scavenge_until_all_done (void);
static StgWord inc_running (void);
static StgWord dec_running (void);
-static void wakeup_gc_threads (nat n_threads, nat me);
-static void shutdown_gc_threads (nat n_threads, nat me);
+static void wakeup_gc_threads (nat me);
+static void shutdown_gc_threads (nat me);
+static void collect_gct_blocks (void);
#if 0 && defined(DEBUG)
static void gcCAFs (void);
{
bdescr *bd;
generation *gen;
- lnat live, allocated, max_copied, avg_copied, slop;
+ lnat live_blocks, live_words, allocated, max_copied, avg_copied;
gc_thread *saved_gct;
- nat g, t, n;
+ nat g, n;
// necessary if we stole a callee-saves register for gct:
saved_gct = gct;
ASSERT(sizeof(gen_workspace) == 16 * sizeof(StgWord));
// otherwise adjust the padding in gen_workspace.
- // tell the stats department that we've started a GC
- stat_startGC();
+ // this is the main thread
+ SET_GCT(gc_threads[cap->no]);
- // tell the STM to discard any cached closures it's hoping to re-use
- stmPreGCHook();
+ // tell the stats department that we've started a GC
+ stat_startGC(gct);
// lock the StablePtr table
stablePtrPreGC();
/* Approximate how much we allocated.
* Todo: only when generating stats?
*/
- allocated = calcAllocated();
+ allocated = calcAllocated(rtsFalse/* don't count the nursery yet */);
/* Figure out which generation to collect
*/
#endif
// check sanity *before* GC
- IF_DEBUG(sanity, checkSanity(rtsTrue));
-
- // Initialise all our gc_thread structures
- for (t = 0; t < n_gc_threads; t++) {
- init_gc_thread(gc_threads[t]);
- }
+ IF_DEBUG(sanity, checkSanity(rtsFalse /* before GC */, major_gc));
// Initialise all the generations/steps that we're collecting.
for (g = 0; g <= N; g++) {
- init_collected_gen(g,n_gc_threads);
+ prepare_collected_gen(&generations[g]);
}
-
// Initialise all the generations/steps that we're *not* collecting.
for (g = N+1; g < RtsFlags.GcFlags.generations; g++) {
- init_uncollected_gen(g,n_gc_threads);
+ prepare_uncollected_gen(&generations[g]);
}
+ // Prepare this gc_thread
+ init_gc_thread(gct);
+
/* Allocate a mark stack if we're doing a major collection.
*/
if (major_gc && oldest_gen->mark) {
mark_sp = NULL;
}
- // this is the main thread
-#ifdef THREADED_RTS
- if (n_gc_threads == 1) {
- SET_GCT(gc_threads[0]);
- } else {
- SET_GCT(gc_threads[cap->no]);
- }
-#else
-SET_GCT(gc_threads[0]);
-#endif
-
/* -----------------------------------------------------------------------
* follow all the roots that we know about:
*/
// NB. do this after the mutable lists have been saved above, otherwise
// the other GC threads will be writing into the old mutable lists.
inc_running();
- wakeup_gc_threads(n_gc_threads, gct->thread_index);
+ wakeup_gc_threads(gct->thread_index);
- // Mutable lists from each generation > N
- // we want to *scavenge* these roots, not evacuate them: they're not
- // going to move in this GC.
- // Also do them in reverse generation order, for the usual reason:
- // namely to reduce the likelihood of spurious old->new pointers.
- //
- for (g = RtsFlags.GcFlags.generations-1; g > N; g--) {
-#if defined(THREADED_RTS)
- if (n_gc_threads > 1) {
- scavenge_mutable_list(generations[g].saved_mut_list, &generations[g]);
- } else {
- scavenge_mutable_list1(generations[g].saved_mut_list, &generations[g]);
- }
-#else
- scavenge_mutable_list(generations[g].saved_mut_list, &generations[g]);
-#endif
- freeChain_sync(generations[g].saved_mut_list);
- generations[g].saved_mut_list = NULL;
-
- }
+ traceEventGcWork(gct->cap);
// scavenge the capability-private mutable lists. This isn't part
// of markSomeCapabilities() because markSomeCapabilities() can only
#endif
}
} else {
- scavenge_capability_mut_lists(&capabilities[gct->thread_index]);
+ scavenge_capability_mut_lists(gct->cap);
}
// follow roots from the CAF list (used by GHCi)
- gct->evac_gen = 0;
+ gct->evac_gen_no = 0;
markCAFs(mark_root, gct);
// follow all the roots that the application knows about.
- gct->evac_gen = 0;
- markSomeCapabilities(mark_root, gct, gct->thread_index, n_gc_threads,
- rtsTrue/*prune sparks*/);
+ gct->evac_gen_no = 0;
+ if (n_gc_threads == 1) {
+ for (n = 0; n < n_capabilities; n++) {
+ markCapability(mark_root, gct, &capabilities[n],
+ rtsTrue/*don't mark sparks*/);
+ }
+ } else {
+ markCapability(mark_root, gct, cap, rtsTrue/*don't mark sparks*/);
+ }
+
+ markScheduler(mark_root, gct);
#if defined(RTS_USER_SIGNALS)
// mark the signal handlers (signals should be already blocked)
// The other threads are now stopped. We might recurse back to
// here, but from now on this is the only thread.
- // if any blackholes are alive, make the threads that wait on
- // them alive too.
- if (traverseBlackholeQueue()) {
- inc_running();
- continue;
- }
-
// must be last... invariant is that everything is fully
// scavenged at this point.
if (traverseWeakPtrList()) { // returns rtsTrue if evaced something
break;
}
- shutdown_gc_threads(n_gc_threads, gct->thread_index);
+ shutdown_gc_threads(gct->thread_index);
// Now see which stable names are still alive.
gcStablePtrTable();
+#ifdef THREADED_RTS
+ if (n_gc_threads == 1) {
+ for (n = 0; n < n_capabilities; n++) {
+ pruneSparkQueue(&capabilities[n]);
+ }
+ } else {
+ pruneSparkQueue(gct->cap);
+ }
+#endif
+
#ifdef PROFILING
// We call processHeapClosureForDead() on every closure destroyed during
// the current garbage collection, so we invoke LdvCensusForDead().
}
}
- // For each workspace, in each thread, move the copied blocks to the step
- {
- gc_thread *thr;
- gen_workspace *ws;
- bdescr *prev, *next;
-
- for (t = 0; t < n_gc_threads; t++) {
- thr = gc_threads[t];
-
- for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
- ws = &thr->gens[g];
-
- // Push the final block
- if (ws->todo_bd) {
- push_scanned_block(ws->todo_bd, ws);
- }
-
- ASSERT(gct->scan_bd == NULL);
- ASSERT(countBlocks(ws->scavd_list) == ws->n_scavd_blocks);
-
- prev = NULL;
- for (bd = ws->scavd_list; bd != NULL; bd = bd->link) {
- ws->gen->n_words += bd->free - bd->start;
- prev = bd;
- }
- if (prev != NULL) {
- prev->link = ws->gen->blocks;
- ws->gen->blocks = ws->scavd_list;
- }
- ws->gen->n_blocks += ws->n_scavd_blocks;
- }
- }
-
- // Add all the partial blocks *after* we've added all the full
- // blocks. This is so that we can grab the partial blocks back
- // again and try to fill them up in the next GC.
- for (t = 0; t < n_gc_threads; t++) {
- thr = gc_threads[t];
-
- for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
- ws = &thr->gens[g];
-
- prev = NULL;
- for (bd = ws->part_list; bd != NULL; bd = next) {
- next = bd->link;
- if (bd->free == bd->start) {
- if (prev == NULL) {
- ws->part_list = next;
- } else {
- prev->link = next;
- }
- freeGroup(bd);
- ws->n_part_blocks--;
- } else {
- ws->gen->n_words += bd->free - bd->start;
- prev = bd;
- }
- }
- if (prev != NULL) {
- prev->link = ws->gen->blocks;
- ws->gen->blocks = ws->part_list;
- }
- ws->gen->n_blocks += ws->n_part_blocks;
-
- ASSERT(countBlocks(ws->gen->blocks) == ws->gen->n_blocks);
- ASSERT(countOccupied(ws->gen->blocks) == ws->gen->n_words);
- }
- }
- }
-
// Finally: compact or sweep the oldest generation.
if (major_gc && oldest_gen->mark) {
if (oldest_gen->compact)
sweep(oldest_gen);
}
- /* run through all the generations/steps and tidy up
- */
copied = 0;
max_copied = 0;
avg_copied = 0;
}
}
+ // Run through all the generations/steps and tidy up.
+ // We're going to:
+ // - count the amount of "live" data (live_words, live_blocks)
+ // - count the amount of "copied" data in this GC (copied)
+ // - free from-space
+ // - make to-space the new from-space (set BF_EVACUATED on all blocks)
+ //
+ live_words = 0;
+ live_blocks = 0;
+
for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
if (g == N) {
// stats. Every mutable list is copied during every GC.
if (g > 0) {
nat mut_list_size = 0;
- for (bd = generations[g].mut_list; bd != NULL; bd = bd->link) {
- mut_list_size += bd->free - bd->start;
- }
for (n = 0; n < n_capabilities; n++) {
- for (bd = capabilities[n].mut_lists[g];
- bd != NULL; bd = bd->link) {
- mut_list_size += bd->free - bd->start;
- }
+ mut_list_size += countOccupied(capabilities[n].mut_lists[g]);
}
copied += mut_list_size;
freeChain(gen->large_objects);
gen->large_objects = gen->scavenged_large_objects;
gen->n_large_blocks = gen->n_scavenged_large_blocks;
- gen->n_new_large_blocks = 0;
- ASSERT(countBlocks(gen->large_objects) == gen->n_large_blocks);
+ gen->n_new_large_words = 0;
}
else // for generations > N
{
// add the new blocks we promoted during this GC
gen->n_large_blocks += gen->n_scavenged_large_blocks;
- ASSERT(countBlocks(gen->large_objects) == gen->n_large_blocks);
+ }
+
+ ASSERT(countBlocks(gen->large_objects) == gen->n_large_blocks);
+
+ gen->scavenged_large_objects = NULL;
+ gen->n_scavenged_large_blocks = 0;
+
+ // Count "live" data
+ live_words += genLiveWords(gen);
+ live_blocks += genLiveBlocks(gen);
+
+ // add in the partial blocks in the gen_workspaces, but ignore gen 0
+ // if this is a local GC (we can't count another capability's part_list)
+ {
+ nat i;
+ for (i = 0; i < n_capabilities; i++) {
+ live_words += gcThreadLiveWords(i, gen->no);
+ live_blocks += gcThreadLiveBlocks(i, gen->no);
+ }
}
} // for all generations
// update the max size of older generations after a major GC
resize_generations();
- // Calculate the amount of live data for stats.
- live = calcLiveWords();
-
- // Free the small objects allocated via allocate(), since this will
- // all have been copied into G0S1 now.
- alloc_blocks_lim = RtsFlags.GcFlags.minAllocAreaSize;
-
// Start a new pinned_object_block
for (n = 0; n < n_capabilities; n++) {
capabilities[n].pinned_object_block = NULL;
}
}
+ // Reset the nursery: make the blocks empty
+ allocated += clearNurseries();
+
resize_nursery();
- // mark the garbage collected CAFs as dead
+ resetNurseries();
+
+ // mark the garbage collected CAFs as dead
#if 0 && defined(DEBUG) // doesn't work at the moment
if (major_gc) { gcCAFs(); }
#endif
}
}
- // Reset the nursery
- resetNurseries();
+ // Update the stable pointer hash table.
+ updateStablePtrTable(major_gc);
+
+ // unlock the StablePtr table. Must be before scheduleFinalizers(),
+ // because a finalizer may call hs_free_fun_ptr() or
+ // hs_free_stable_ptr(), both of which access the StablePtr table.
+ stablePtrPostGC();
- // start any pending finalizers
+ // Start any pending finalizers. Must be after
+ // updateStablePtrTable() and stablePtrPostGC() (see #4221).
RELEASE_SM_LOCK;
scheduleFinalizers(cap, old_weak_ptr_list);
ACQUIRE_SM_LOCK;
-
- // send exceptions to any threads which were about to die
+
+ // check sanity after GC
+ // before resurrectThreads(), because that might overwrite some
+ // closures, which will cause problems with THREADED where we don't
+ // fill slop.
+ IF_DEBUG(sanity, checkSanity(rtsTrue /* after GC */, major_gc));
+
+ // send exceptions to any threads which were about to die
RELEASE_SM_LOCK;
resurrectThreads(resurrected_threads);
- performPendingThrowTos(exception_threads);
ACQUIRE_SM_LOCK;
- // Update the stable pointer hash table.
- updateStablePtrTable(major_gc);
-
- // check sanity after GC
- IF_DEBUG(sanity, checkSanity(rtsTrue));
+ if (major_gc) {
+ nat need, got;
+ need = BLOCKS_TO_MBLOCKS(n_alloc_blocks);
+ got = mblocks_allocated;
+ /* If the amount of data remains constant, next major GC we'll
+ require (F+1)*need. We leave (F+2)*need in order to reduce
+ repeated deallocation and reallocation. */
+ need = (RtsFlags.GcFlags.oldGenFactor + 2) * need;
+ if (got > need) {
+ returnMemoryToOS(got - need);
+ }
+ }
- // extra GC trace info
+ // extra GC trace info
IF_DEBUG(gc, statDescribeGens());
#ifdef DEBUG
#endif
// ok, GC over: tell the stats department what happened.
- slop = calcLiveBlocks() * BLOCK_SIZE_W - live;
- stat_endGC(allocated, live, copied, N, max_copied, avg_copied, slop);
-
- // unlock the StablePtr table
- stablePtrPostGC();
+ stat_endGC(gct, allocated, live_words,
+ copied, N, max_copied, avg_copied,
+ live_blocks * BLOCK_SIZE_W - live_words /* slop */);
// Guess which generation we'll collect *next* time
initialise_N(force_major_gc);
nat g;
gen_workspace *ws;
+ t->cap = &capabilities[n];
+
#ifdef THREADED_RTS
t->id = 0;
initSpinLock(&t->gc_spin);
ASSERT(g == ws->gen->no);
ws->my_gct = t;
- ws->todo_bd = NULL;
+ // We want to call
+ // alloc_todo_block(ws,0);
+ // but can't, because it uses gct which isn't set up at this point.
+ // Hence, allocate a block for todo_bd manually:
+ {
+ bdescr *bd = allocBlock(); // no lock, locks aren't initialised yet
+ initBdescr(bd, ws->gen, ws->gen->to);
+ bd->flags = BF_EVACUATED;
+ bd->u.scan = bd->free = bd->start;
+
+ ws->todo_bd = bd;
+ ws->todo_free = bd->free;
+ ws->todo_lim = bd->start + BLOCK_SIZE_W;
+ }
+
ws->todo_q = newWSDeque(128);
ws->todo_overflow = NULL;
ws->n_todo_overflow = 0;
-
+ ws->todo_large_objects = NULL;
+
ws->part_list = NULL;
ws->n_part_blocks = 0;
#endif
gct->no_work++;
+#if defined(THREADED_RTS)
+ yieldThread();
+#endif
return rtsFalse;
}
loop:
- traceEvent(&capabilities[gct->thread_index], EVENT_GC_WORK);
-
#if defined(THREADED_RTS)
if (n_gc_threads > 1) {
scavenge_loop();
scavenge_loop();
#endif
+ collect_gct_blocks();
+
// scavenge_loop() only exits when there's no work to do
r = dec_running();
- traceEvent(&capabilities[gct->thread_index], EVENT_GC_IDLE);
+ traceEventGcIdle(gct->cap);
debugTrace(DEBUG_gc, "%d GC threads still running", r);
// usleep(1);
if (any_work()) {
inc_running();
+ traceEventGcWork(gct->cap);
goto loop;
}
// any_work() does not remove the work from the queue, it
// scavenge_loop() to perform any pending work.
}
- traceEvent(&capabilities[gct->thread_index], EVENT_GC_DONE);
+ traceEventGcDone(gct->cap);
}
#if defined(THREADED_RTS)
gct = gc_threads[cap->no];
gct->id = osThreadId();
+ stat_gcWorkerThreadStart(gct);
+
// Wait until we're told to wake up
RELEASE_SPIN_LOCK(&gct->mut_spin);
gct->wakeup = GC_THREAD_STANDING_BY;
}
papi_thread_start_gc1_count(gct->papi_events);
#endif
-
+
+ init_gc_thread(gct);
+
+ traceEventGcWork(gct->cap);
+
// Every thread evacuates some roots.
- gct->evac_gen = 0;
- markSomeCapabilities(mark_root, gct, gct->thread_index, n_gc_threads,
- rtsTrue/*prune sparks*/);
- scavenge_capability_mut_lists(&capabilities[gct->thread_index]);
+ gct->evac_gen_no = 0;
+ markCapability(mark_root, gct, cap, rtsTrue/*prune sparks*/);
+ scavenge_capability_mut_lists(cap);
scavenge_until_all_done();
+#ifdef THREADED_RTS
+ // Now that the whole heap is marked, we discard any sparks that
+ // were found to be unreachable. The main GC thread is currently
+ // marking heap reachable via weak pointers, so it is
+ // non-deterministic whether a spark will be retained if it is
+ // only reachable via weak pointers. To fix this problem would
+ // require another GC barrier, which is too high a price.
+ pruneSparkQueue(cap);
+#endif
+
#ifdef USE_PAPI
// count events in this thread towards the GC totals
papi_thread_stop_gc1_count(gct->papi_events);
ACQUIRE_SPIN_LOCK(&gct->mut_spin);
debugTrace(DEBUG_gc, "GC thread %d on my way...", gct->thread_index);
+ // record the time spent doing GC in the Task structure
+ stat_gcWorkerThreadDone(gct);
+
SET_GCT(saved_gct);
}
void
waitForGcThreads (Capability *cap USED_IF_THREADS)
{
- nat n_threads = RtsFlags.ParFlags.nNodes;
- nat me = cap->no;
+ const nat n_threads = RtsFlags.ParFlags.nNodes;
+ const nat me = cap->no;
nat i, j;
rtsBool retry = rtsTrue;
}
static void
-wakeup_gc_threads (nat n_threads USED_IF_THREADS, nat me USED_IF_THREADS)
+wakeup_gc_threads (nat me USED_IF_THREADS)
{
#if defined(THREADED_RTS)
nat i;
- for (i=0; i < n_threads; i++) {
+
+ if (n_gc_threads == 1) return;
+
+ for (i=0; i < n_gc_threads; i++) {
if (i == me) continue;
inc_running();
debugTrace(DEBUG_gc, "waking up gc thread %d", i);
// standby state, otherwise they may still be executing inside
// any_work(), and may even remain awake until the next GC starts.
static void
-shutdown_gc_threads (nat n_threads USED_IF_THREADS, nat me USED_IF_THREADS)
+shutdown_gc_threads (nat me USED_IF_THREADS)
{
#if defined(THREADED_RTS)
nat i;
- for (i=0; i < n_threads; i++) {
+
+ if (n_gc_threads == 1) return;
+
+ for (i=0; i < n_gc_threads; i++) {
if (i == me) continue;
while (gc_threads[i]->wakeup != GC_THREAD_WAITING_TO_CONTINUE) { write_barrier(); }
}
void
releaseGCThreads (Capability *cap USED_IF_THREADS)
{
- nat n_threads = RtsFlags.ParFlags.nNodes;
- nat me = cap->no;
+ const nat n_threads = RtsFlags.ParFlags.nNodes;
+ const nat me = cap->no;
nat i;
for (i=0; i < n_threads; i++) {
if (i == me) continue;
------------------------------------------------------------------------- */
static void
-init_collected_gen (nat g, nat n_threads)
+prepare_collected_gen (generation *gen)
{
- nat t, i;
+ nat i, g, n;
gen_workspace *ws;
- generation *gen;
- bdescr *bd;
+ bdescr *bd, *next;
// Throw away the current mutable list. Invariant: the mutable
// list always has at least one block; this means we can avoid a
// check for NULL in recordMutable().
+ g = gen->no;
if (g != 0) {
- freeChain(generations[g].mut_list);
- generations[g].mut_list = allocBlock();
- for (i = 0; i < n_capabilities; i++) {
+ for (i = 0; i < n_capabilities; i++) {
freeChain(capabilities[i].mut_lists[g]);
capabilities[i].mut_lists[g] = allocBlock();
}
gen->live_estimate = 0;
// initialise the large object queues.
- gen->scavenged_large_objects = NULL;
- gen->n_scavenged_large_blocks = 0;
-
+ ASSERT(gen->scavenged_large_objects == NULL);
+ ASSERT(gen->n_scavenged_large_blocks == 0);
+
+ // grab all the partial blocks stashed in the gc_thread workspaces and
+ // move them to the old_blocks list of this gen.
+ for (n = 0; n < n_capabilities; n++) {
+ ws = &gc_threads[n]->gens[gen->no];
+
+ for (bd = ws->part_list; bd != NULL; bd = next) {
+ next = bd->link;
+ bd->link = gen->old_blocks;
+ gen->old_blocks = bd;
+ gen->n_old_blocks += bd->blocks;
+ }
+ ws->part_list = NULL;
+ ws->n_part_blocks = 0;
+
+ ASSERT(ws->scavd_list == NULL);
+ ASSERT(ws->n_scavd_blocks == 0);
+
+ if (ws->todo_free != ws->todo_bd->start) {
+ ws->todo_bd->free = ws->todo_free;
+ ws->todo_bd->link = gen->old_blocks;
+ gen->old_blocks = ws->todo_bd;
+ gen->n_old_blocks += ws->todo_bd->blocks;
+ alloc_todo_block(ws,0); // always has one block.
+ }
+ }
+
// mark the small objects as from-space
for (bd = gen->old_blocks; bd; bd = bd->link) {
bd->flags &= ~BF_EVACUATED;
if (!(bd->flags & BF_FRAGMENTED)) {
bd->flags |= BF_MARKED;
}
+
+ // BF_SWEPT should be marked only for blocks that are being
+ // collected in sweep()
+ bd->flags &= ~BF_SWEPT;
}
}
}
-
- // For each GC thread, for each step, allocate a "todo" block to
- // store evacuated objects to be scavenged, and a block to store
- // evacuated objects that do not need to be scavenged.
- for (t = 0; t < n_threads; t++) {
- ws = &gc_threads[t]->gens[g];
-
- 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;
- ASSERT(looksEmptyWSDeque(ws->todo_q));
- alloc_todo_block(ws,0);
-
- ws->todo_overflow = NULL;
- ws->n_todo_overflow = 0;
-
- ws->scavd_list = NULL;
- ws->n_scavd_blocks = 0;
- }
}
/* ----------------------------------------------------------------------------
+ Save the mutable lists in saved_mut_lists
+ ------------------------------------------------------------------------- */
+
+static void
+stash_mut_list (Capability *cap, nat gen_no)
+{
+ cap->saved_mut_lists[gen_no] = cap->mut_lists[gen_no];
+ cap->mut_lists[gen_no] = allocBlock_sync();
+}
+
+/* ----------------------------------------------------------------------------
Initialise a generation that is *not* to be collected
------------------------------------------------------------------------- */
static void
-init_uncollected_gen (nat g, nat threads)
+prepare_uncollected_gen (generation *gen)
{
- nat t, n;
- gen_workspace *ws;
- generation *gen;
- bdescr *bd;
+ nat i;
+
+
+ ASSERT(gen->no > 0);
// save the current mutable lists for this generation, and
// allocate a fresh block for each one. We'll traverse these
// mutable lists as roots early on in the GC.
- generations[g].saved_mut_list = generations[g].mut_list;
- generations[g].mut_list = allocBlock();
- for (n = 0; n < n_capabilities; n++) {
- capabilities[n].saved_mut_lists[g] = capabilities[n].mut_lists[g];
- capabilities[n].mut_lists[g] = allocBlock();
+ for (i = 0; i < n_capabilities; i++) {
+ stash_mut_list(&capabilities[i], gen->no);
}
- gen = &generations[g];
+ ASSERT(gen->scavenged_large_objects == NULL);
+ ASSERT(gen->n_scavenged_large_blocks == 0);
+}
- gen->scavenged_large_objects = NULL;
- gen->n_scavenged_large_blocks = 0;
+/* -----------------------------------------------------------------------------
+ Collect the completed blocks from a GC thread and attach them to
+ the generation.
+ -------------------------------------------------------------------------- */
- for (t = 0; t < threads; t++) {
- ws = &gc_threads[t]->gens[g];
-
- ASSERT(looksEmptyWSDeque(ws->todo_q));
- ws->todo_large_objects = NULL;
-
- ws->part_list = NULL;
- ws->n_part_blocks = 0;
+static void
+collect_gct_blocks (void)
+{
+ nat g;
+ gen_workspace *ws;
+ bdescr *bd, *prev;
+
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ ws = &gct->gens[g];
- ws->scavd_list = NULL;
- ws->n_scavd_blocks = 0;
+ // there may still be a block attached to ws->todo_bd;
+ // leave it there to use next time.
+
+ if (ws->scavd_list != NULL) {
+ ACQUIRE_SPIN_LOCK(&ws->gen->sync);
+
+ ASSERT(gct->scan_bd == NULL);
+ ASSERT(countBlocks(ws->scavd_list) == ws->n_scavd_blocks);
- // If the block at the head of the list in this generation
- // is less than 3/4 full, then use it as a todo block.
- if (gen->blocks && isPartiallyFull(gen->blocks))
- {
- ws->todo_bd = gen->blocks;
- ws->todo_free = ws->todo_bd->free;
- ws->todo_lim = ws->todo_bd->start + BLOCK_SIZE_W;
- gen->blocks = gen->blocks->link;
- gen->n_blocks -= 1;
- gen->n_words -= ws->todo_bd->free - ws->todo_bd->start;
- ws->todo_bd->link = NULL;
- // we must scan from the current end point.
- ws->todo_bd->u.scan = ws->todo_bd->free;
- }
- else
- {
- ws->todo_bd = NULL;
- alloc_todo_block(ws,0);
- }
- }
+ prev = NULL;
+ for (bd = ws->scavd_list; bd != NULL; bd = bd->link) {
+ ws->gen->n_words += bd->free - bd->start;
+ prev = bd;
+ }
+ if (prev != NULL) {
+ prev->link = ws->gen->blocks;
+ ws->gen->blocks = ws->scavd_list;
+ }
+ ws->gen->n_blocks += ws->n_scavd_blocks;
- // deal out any more partial blocks to the threads' part_lists
- t = 0;
- while (gen->blocks && isPartiallyFull(gen->blocks))
- {
- bd = gen->blocks;
- gen->blocks = bd->link;
- ws = &gc_threads[t]->gens[g];
- bd->link = ws->part_list;
- ws->part_list = bd;
- ws->n_part_blocks += 1;
- bd->u.scan = bd->free;
- gen->n_blocks -= 1;
- gen->n_words -= bd->free - bd->start;
- t++;
- if (t == n_gc_threads) t = 0;
+ ws->scavd_list = NULL;
+ ws->n_scavd_blocks = 0;
+
+ RELEASE_SPIN_LOCK(&ws->gen->sync);
+ }
}
}
t->static_objects = END_OF_STATIC_LIST;
t->scavenged_static_objects = END_OF_STATIC_LIST;
t->scan_bd = NULL;
- t->mut_lists = capabilities[t->thread_index].mut_lists;
- t->evac_gen = 0;
+ t->mut_lists = t->cap->mut_lists;
+ t->evac_gen_no = 0;
t->failed_to_evac = rtsFalse;
t->eager_promotion = rtsTrue;
t->thunk_selector_depth = 0;
if (major_gc && RtsFlags.GcFlags.generations > 1) {
nat live, size, min_alloc, words;
- nat max = RtsFlags.GcFlags.maxHeapSize;
- nat gens = RtsFlags.GcFlags.generations;
+ const nat max = RtsFlags.GcFlags.maxHeapSize;
+ const nat gens = RtsFlags.GcFlags.generations;
// live in the oldest generations
if (oldest_gen->live_estimate != 0) {
// Auto-enable compaction when the residency reaches a
// certain percentage of the maximum heap size (default: 30%).
- if (RtsFlags.GcFlags.generations > 1 &&
- (RtsFlags.GcFlags.compact ||
- (max > 0 &&
- oldest_gen->n_blocks >
- (RtsFlags.GcFlags.compactThreshold * max) / 100))) {
+ if (RtsFlags.GcFlags.compact ||
+ (max > 0 &&
+ oldest_gen->n_blocks >
+ (RtsFlags.GcFlags.compactThreshold * max) / 100)) {
oldest_gen->mark = 1;
oldest_gen->compact = 1;
// debugBelch("compaction: on\n", live);
static void
resize_nursery (void)
{
- lnat min_nursery = RtsFlags.GcFlags.minAllocAreaSize * n_capabilities;
+ const lnat min_nursery = RtsFlags.GcFlags.minAllocAreaSize * n_capabilities;
if (RtsFlags.GcFlags.generations == 1)
{ // Two-space collector:
if (RtsFlags.GcFlags.heapSizeSuggestion)
{
long blocks;
- nat needed = calcNeeded(); // approx blocks needed at next GC
+ const nat needed = calcNeeded(); // approx blocks needed at next GC
/* Guess how much will be live in generation 0 step 0 next time.
* A good approximation is obtained by finding the
projects / ghc-hetmet.git / blobdiff