*
* ---------------------------------------------------------------------------*/
-#include <unistd.h>
-
#include "Rts.h"
#include "RtsFlags.h"
#include "Storage.h"
StgClosure* p;
const StgInfoTable *info;
+ debugTrace(DEBUG_gc, "scavenging static objects");
+
/* Always evacuate straight to the oldest generation for static
* objects */
gct->evac_step = &oldest_gen->steps[0];
bdescr *bd;
StgPtr p;
- gct->evac_step = ws->stp;
+ gct->evac_step = ws->step;
bd = ws->todo_large_objects;
// the front when evacuating.
ws->todo_large_objects = bd->link;
- ACQUIRE_SPIN_LOCK(&ws->stp->sync_large_objects);
- dbl_link_onto(bd, &ws->stp->scavenged_large_objects);
- ws->stp->n_scavenged_large_blocks += bd->blocks;
- RELEASE_SPIN_LOCK(&ws->stp->sync_large_objects);
+ ACQUIRE_SPIN_LOCK(&ws->step->sync_large_objects);
+ dbl_link_onto(bd, &ws->step->scavenged_large_objects);
+ ws->step->n_scavenged_large_blocks += bd->blocks;
+ RELEASE_SPIN_LOCK(&ws->step->sync_large_objects);
p = bd->start;
if (scavenge_one(p)) {
- if (ws->stp->gen_no > 0) {
- recordMutableGen_GC((StgClosure *)p, ws->stp->gen);
+ if (ws->step->gen_no > 0) {
+ recordMutableGen_GC((StgClosure *)p, ws->step->gen);
}
}
}
Scavenge a block
------------------------------------------------------------------------- */
-#define MINOR_GC
+#define PARALLEL_GC
#include "Scav.c-inc"
-#undef MINOR_GC
+#undef PARALLEL_GC
#include "Scav.c-inc"
/* ----------------------------------------------------------------------------
- Find the oldest full block to scavenge, and scavenge it.
+ Look for work to do.
+
+ We look for the oldest step that has either a todo block that can
+ be scanned, or a block of work on the global queue that we can
+ scan.
+
+ It is important to take work from the *oldest* generation that we
+ has work available, because that minimizes the likelihood of
+ evacuating objects into a young generation when they should have
+ been eagerly promoted. This really does make a difference (the
+ cacheprof benchmark is one that is affected).
+
+ We also want to scan the todo block if possible before grabbing
+ work from the global queue, the reason being that we don't want to
+ steal work from the global queue and starve other threads if there
+ is other work we can usefully be doing.
------------------------------------------------------------------------- */
static rtsBool
-scavenge_find_global_work (void)
+scavenge_find_work (void)
{
- bdescr *bd;
int s;
- rtsBool flag;
step_workspace *ws;
+ rtsBool did_something, did_anything;
+ bdescr *bd;
- gct->scav_global_work++;
-
- flag = rtsFalse;
- 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 ((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 (flag) return rtsTrue;
- }
- return rtsFalse;
-}
-
-/* ----------------------------------------------------------------------------
- Look for local work to do.
-
- We can have outstanding scavenging to do if, for any of the workspaces,
-
- - the scan block is the same as the todo block, and new objects
- have been evacuated to the todo block.
-
- - the scan block *was* the same as the todo block, but the todo
- block filled up and a new one has been allocated.
- ------------------------------------------------------------------------- */
-
-static rtsBool
-scavenge_find_local_work (void)
-{
- int s;
- step_workspace *ws;
- rtsBool flag;
+ gct->scav_find_work++;
- gct->scav_local_work++;
+ did_anything = rtsFalse;
- flag = rtsFalse;
+loop:
+ did_something = rtsFalse;
for (s = total_steps-1; s >= 0; s--) {
if (s == 0 && RtsFlags.GcFlags.generations > 1) {
continue;
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 (ws->scan_bd != NULL && ws->scan_bd->u.scan < ws->scan_bd->free)
{
- if (N == 0) {
- scavenge_block0(ws->scan_bd, ws->scan);
+ if (n_gc_threads == 1) {
+ scavenge_block1(ws->scan_bd);
} else {
- scavenge_block(ws->scan_bd, ws->scan);
+ scavenge_block(ws->scan_bd);
}
- ws->scan = ws->scan_bd->free;
- flag = rtsTrue;
+ did_something = rtsTrue;
}
- if (ws->scan_bd != NULL && ws->scan == ws->scan_bd->free
- && ws->scan_bd != ws->todo_bd)
+ if (ws->scan_bd != NULL && ws->scan_bd != ws->todo_bd)
{
+ ASSERT(ws->scan_bd->u.scan == ws->scan_bd->free);
// we're not going to evac any more objects into
// this block, so push it now.
- push_scan_block(ws->scan_bd, ws);
+ push_scanned_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;
+ // we might be able to scan the todo block now.
+ did_something = rtsTrue;
+ }
+
+ if (did_something) break;
+
+ // If we have any large objects to scavenge, do them now.
+ if (ws->todo_large_objects) {
+ scavenge_large(ws);
+ did_something = rtsTrue;
+ break;
+ }
+
+ 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);
+ } else {
+ scavenge_block(bd);
+ }
+ push_scanned_block(bd, ws);
+ did_something = rtsTrue;
+ break;
}
-
- if (flag) return rtsTrue;
}
- return rtsFalse;
+
+ if (did_something) {
+ did_anything = rtsTrue;
+ goto loop;
+ }
+ // only return when there is no more work to do
+
+ return did_anything;
}
/* ----------------------------------------------------------------------------
// local work. Only if all the global work has been exhausted
// do we start scavenging the fragments of blocks in the local
// workspaces.
- if (scavenge_find_global_work()) goto loop;
- if (scavenge_find_local_work()) goto loop;
+ if (scavenge_find_work()) goto loop;
if (work_to_do) goto loop;
}
}
ws = &gct->steps[s];
if (ws->todo_large_objects) return rtsTrue;
- if (ws->stp->todos) return rtsTrue;
+ if (ws->step->todos) return rtsTrue;
}
gct->no_work++;
- usleep(1);
return rtsFalse;
}
projects / ghc-hetmet.git / blobdiff