6 files changed, 11 insertions, 1 deletions
diff --git a/erts/emulator/beam/erl_afit_alloc.c b/erts/emulator/beam/erl_afit_alloc.c
index b45201af42..d03d6a591c 100644
--- a/erts/emulator/beam/erl_afit_alloc.c
+++ b/erts/emulator/beam/erl_afit_alloc.c
@@ -86,6 +86,7 @@ erts_afalc_start(AFAllctr_t *afallctr,
 
     init->sbmbct = 0; /* Small mbc not supported by afit */
 
+    allctr->mbc_header_size		= sizeof(Carrier_t);
     allctr->min_mbc_size		= MIN_MBC_SZ;
     allctr->min_mbc_first_free_size	= MIN_MBC_FIRST_FREE_SZ;
     allctr->min_block_size		= sizeof(AFFreeBlock_t);
diff --git a/erts/emulator/beam/erl_alloc_util.c b/erts/emulator/beam/erl_alloc_util.c
index c57ddc424e..bf7d561b00 100644
--- a/erts/emulator/beam/erl_alloc_util.c
+++ b/erts/emulator/beam/erl_alloc_util.c
@@ -304,7 +304,7 @@ MBC after deallocating first block:
 
 #define SBC_HEADER_SIZE	   (UNIT_CEILING(sizeof(Carrier_t) + ABLK_HDR_SZ) \
 			    - ABLK_HDR_SZ)
-#define MBC_HEADER_SIZE(AP) SBC_HEADER_SIZE
+#define MBC_HEADER_SIZE(AP) ((AP)->mbc_header_size)
 
 
 #define MSEG_CARRIER_HDR_FLAG		(((UWord) 1) << 0)
@@ -4256,6 +4256,8 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
     if (!allctr->get_next_mbc_size)
 	allctr->get_next_mbc_size = get_next_mbc_size;
 
+    if (allctr->mbc_header_size < sizeof(Carrier_t))
+	goto error;
 #ifdef ERTS_SMP
     allctr->dd.use = 0;
     if (init->tpref) {
@@ -4264,6 +4266,9 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
 	allctr->dd.ix = init->ix;
     }
 #endif
+    allctr->mbc_header_size = (UNIT_CEILING(allctr->mbc_header_size
+					    + ABLK_HDR_SZ)
+			       - ABLK_HDR_SZ);
 
     if (allctr->main_carrier_size) {
 	Block_t *blk;
diff --git a/erts/emulator/beam/erl_alloc_util.h b/erts/emulator/beam/erl_alloc_util.h
index 404ba66971..af8f72ed7d 100644
--- a/erts/emulator/beam/erl_alloc_util.h
+++ b/erts/emulator/beam/erl_alloc_util.h
@@ -448,6 +448,7 @@ struct Allctr_t_ {
 #endif
 
     /* */
+    Uint		mbc_header_size;
     Uint		min_mbc_size;
     Uint		min_mbc_first_free_size;
     Uint		min_block_size;
diff --git a/erts/emulator/beam/erl_ao_firstfit_alloc.c b/erts/emulator/beam/erl_ao_firstfit_alloc.c
index e277006e58..1570daf90e 100644
--- a/erts/emulator/beam/erl_ao_firstfit_alloc.c
+++ b/erts/emulator/beam/erl_ao_firstfit_alloc.c
@@ -216,6 +216,7 @@ erts_aoffalc_start(AOFFAllctr_t *alc,
     sys_memcpy((void *) alc, (void *) &zero.allctr, sizeof(AOFFAllctr_t));
 
     alc->bf_within_carrier              = aoffinit->bf_within_carrier;
+    allctr->mbc_header_size		= sizeof(Carrier_t);
     allctr->min_mbc_size		= MIN_MBC_SZ;
     allctr->min_mbc_first_free_size	= MIN_MBC_FIRST_FREE_SZ;
     allctr->min_block_size		= sizeof(AOFF_RBTree_t);
diff --git a/erts/emulator/beam/erl_bestfit_alloc.c b/erts/emulator/beam/erl_bestfit_alloc.c
index e3fc8f4cb1..42c7c9bbe2 100644
--- a/erts/emulator/beam/erl_bestfit_alloc.c
+++ b/erts/emulator/beam/erl_bestfit_alloc.c
@@ -179,6 +179,7 @@ erts_bfalc_start(BFAllctr_t *bfallctr,
     bfallctr->address_order		= bfinit->ao;
 
 
+    allctr->mbc_header_size		= sizeof(Carrier_t);
     allctr->min_mbc_size		= MIN_MBC_SZ;
     allctr->min_mbc_first_free_size	= MIN_MBC_FIRST_FREE_SZ;
     allctr->min_block_size		= (bfinit->ao
diff --git a/erts/emulator/beam/erl_goodfit_alloc.c b/erts/emulator/beam/erl_goodfit_alloc.c
index 79d8b40f8c..fce443c101 100644
--- a/erts/emulator/beam/erl_goodfit_alloc.c
+++ b/erts/emulator/beam/erl_goodfit_alloc.c
@@ -205,6 +205,7 @@ erts_gfalc_start(GFAllctr_t *gfallctr,
 
     init->sbmbct = 0; /* Small mbc not yet supported by goodfit */
 
+    allctr->mbc_header_size		= sizeof(Carrier_t);
     allctr->min_mbc_size		= MIN_MBC_SZ;
     allctr->min_mbc_first_free_size	= MIN_MBC_FIRST_FREE_SZ;
     allctr->min_block_size		= sizeof(GFFreeBlock_t);