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authorRickard Green <[email protected]>2013-06-10 11:46:52 +0200
committerRickard Green <[email protected]>2013-06-10 13:03:20 +0200
commitc4af01028f0e6ed5fe9e7b3054550f3447a3c343 (patch)
treea62ea805e19b634a70f980e7b7e69f3ace5b8ac5 /erts/emulator
parentb8c941265433e1bdff12c49c611349f6abba1a9e (diff)
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erts: Fix management of redirected carrier to deallocate
Diffstat (limited to 'erts/emulator')
-rw-r--r--erts/emulator/beam/erl_alloc_util.c41
1 files changed, 30 insertions, 11 deletions
diff --git a/erts/emulator/beam/erl_alloc_util.c b/erts/emulator/beam/erl_alloc_util.c
index b19e603a5f..bf8a37c71b 100644
--- a/erts/emulator/beam/erl_alloc_util.c
+++ b/erts/emulator/beam/erl_alloc_util.c
@@ -1753,7 +1753,8 @@ handle_delayed_dealloc(Allctr_t *allctr,
if (IS_FREE_LAST_MBC_BLK(blk)) {
/*
* A multiblock carrier that previously has been migrated away
- * from us and now is back to be deallocated...
+ * from us and now is back to be deallocated. For more info
+ * see schedule_dealloc_carrier().
*
* Note that we cannot use FBLK_TO_MBC(blk) since it
* data has been overwritten by the queue.
@@ -1761,6 +1762,12 @@ handle_delayed_dealloc(Allctr_t *allctr,
Carrier_t *crr = FIRST_BLK_TO_MBC(allctr, blk);
ERTS_ALC_CPOOL_ASSERT(ERTS_ALC_IS_CPOOL_ENABLED(allctr));
ERTS_ALC_CPOOL_ASSERT(allctr == crr->cpool.orig_allctr);
+ ERTS_ALC_CPOOL_ASSERT(((erts_aint_t) allctr)
+ != (erts_smp_atomic_read_nob(&crr->allctr)
+ & ~FLG_MASK));
+
+ erts_smp_atomic_set_nob(&crr->allctr, ((erts_aint_t) allctr));
+
schedule_dealloc_carrier(allctr, crr);
}
else {
@@ -3001,7 +3008,7 @@ check_pending_dealloc_carrier(Allctr_t *allctr,
static void
schedule_dealloc_carrier(Allctr_t *allctr, Carrier_t *crr)
{
- Allctr_t *used_allctr;
+ Allctr_t *orig_allctr;
int check_pending_dealloc;
erts_aint_t max_size;
@@ -3010,25 +3017,37 @@ schedule_dealloc_carrier(Allctr_t *allctr, Carrier_t *crr)
return;
}
- used_allctr = crr->cpool.orig_allctr;
+ orig_allctr = crr->cpool.orig_allctr;
- if (allctr != used_allctr) {
+ if (allctr != orig_allctr) {
Block_t *blk = MBC_TO_FIRST_BLK(allctr, crr);
- int cinit = used_allctr->dd.ix - allctr->dd.ix;
+ int cinit = orig_allctr->dd.ix - allctr->dd.ix;
/*
- * Receiver will recognize that this is a carrier to
- * deallocate since the block is an mbc block that
- * is free and last in carrier...
+ * We send the carrier to its origin for deallocation.
+ * This in order:
+ * - not to complicate things for the thread specific
+ * instances of mseg_alloc, and
+ * - to ensure that we always only reuse empty carriers
+ * originating from our own thread specific mseg_alloc
+ * instance which is beneficial on NUMA systems.
+ *
+ * The receiver will recognize that this is a carrier to
+ * deallocate (and not a block which is the common case)
+ * since the block is an mbc block that is free and last
+ * in the carrier.
*/
ERTS_ALC_CPOOL_ASSERT(IS_FREE_LAST_MBC_BLK(blk));
ERTS_ALC_CPOOL_ASSERT(IS_MBC_FIRST_ABLK(allctr, blk));
ERTS_ALC_CPOOL_ASSERT(crr == FBLK_TO_MBC(blk));
- ERTS_ALC_CPOOL_ASSERT(crr == FIRST_BLK_TO_MBC(used_allctr, blk));
+ ERTS_ALC_CPOOL_ASSERT(crr == FIRST_BLK_TO_MBC(allctr, blk));
+ ERTS_ALC_CPOOL_ASSERT(((erts_aint_t) allctr)
+ == (erts_smp_atomic_read_nob(&crr->allctr)
+ & ~FLG_MASK));
- if (ddq_enqueue(&used_allctr->dd.q, BLK2UMEM(blk), cinit))
- erts_alloc_notify_delayed_dealloc(used_allctr->ix);
+ if (ddq_enqueue(&orig_allctr->dd.q, BLK2UMEM(blk), cinit))
+ erts_alloc_notify_delayed_dealloc(orig_allctr->ix);
return;
}