aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorSverker Eriksson <[email protected]>2012-11-09 16:37:28 +0100
committerSverker Eriksson <[email protected]>2012-11-15 14:20:38 +0100
commitb07f01c20f5c01f8a6b5a60e760aad3381e1ff9a (patch)
tree74578f3a8c54d1452a8a8bee549dfd432640426e
parente0ac12699f685cb6de71f72ed7420a70db047d7f (diff)
downloadotp-b07f01c20f5c01f8a6b5a60e760aad3381e1ff9a.tar.gz
otp-b07f01c20f5c01f8a6b5a60e760aad3381e1ff9a.tar.bz2
otp-b07f01c20f5c01f8a6b5a60e760aad3381e1ff9a.zip
erts: Save one word per block for thread preferred allocators
by making use of the new block header scheme to find the carrier header and thereby the allocator.
-rw-r--r--erts/emulator/beam/erl_alloc_util.c178
-rw-r--r--erts/emulator/beam/erl_alloc_util.h1
2 files changed, 62 insertions, 117 deletions
diff --git a/erts/emulator/beam/erl_alloc_util.c b/erts/emulator/beam/erl_alloc_util.c
index b3c948c3e0..d1335598b0 100644
--- a/erts/emulator/beam/erl_alloc_util.c
+++ b/erts/emulator/beam/erl_alloc_util.c
@@ -258,6 +258,11 @@ static Uint max_mseg_carriers;
/* Carriers ... */
+#define SIZEOF_SBC_HDR (UNIT_CEILING(sizeof(Carrier_t) \
+ + FBLK_FTR_SZ \
+ + ABLK_HDR_SZ) \
+ - ABLK_HDR_SZ)
+
#define MSEG_CARRIER_HDR_FLAG (((UWord) 1) << 0)
#define SBC_CARRIER_HDR_FLAG (((UWord) 1) << 1)
@@ -266,11 +271,11 @@ static Uint max_mseg_carriers;
#define SCH_MBC 0
#define SCH_SBC SBC_CARRIER_HDR_FLAG
-#define SET_CARRIER_HDR(C, Sz, F) \
- (ASSERT(((Sz) & FLG_MASK) == 0), (C)->chdr = ((Sz) | (F)))
+#define SET_CARRIER_HDR(C, Sz, F, AP) \
+ (ASSERT(((Sz) & FLG_MASK) == 0), (C)->chdr = ((Sz) | (F)), (C)->allctr = (AP))
-#define BLK2SBC(AP, B) \
- ((Carrier_t *) (((char *) (B)) - (AP)->sbc_header_size))
+#define BLK2SBC(B) \
+ ((Carrier_t *) (((char *) (B)) - SIZEOF_SBC_HDR))
#define FBLK2MBC(AP, B) \
((Carrier_t *) (((char *) (B)) - (AP)->mbc_header_size))
@@ -796,13 +801,9 @@ erts_alcu_fix_alloc_shrink(Allctr_t *allctr, erts_aint32_t flgs)
#define ERTS_ALCU_DD_FIX_TYPE_OFFS \
((sizeof(ErtsAllctrDDBlock_t)-1)/sizeof(UWord) + 1)
-#define ERTS_AU_PREF_ALLOC_IX_MASK \
- ((((UWord) 1) << ERTS_AU_PREF_ALLOC_BITS) - 1)
-#define ERTS_AU_PREF_ALLOC_SIZE_MASK \
- ((((UWord) 1) << (sizeof(UWord)*8 - ERTS_AU_PREF_ALLOC_BITS)) - 1)
-static ERTS_INLINE int
-get_pref_allctr(void *extra, Allctr_t **allctr)
+static ERTS_INLINE Allctr_t*
+get_pref_allctr(void *extra)
{
ErtsAllocatorThrSpec_t *tspec = (ErtsAllocatorThrSpec_t *) extra;
int pref_ix;
@@ -812,34 +813,26 @@ get_pref_allctr(void *extra, Allctr_t **allctr)
ASSERT(sizeof(UWord) == sizeof(Allctr_t *));
ASSERT(0 <= pref_ix && pref_ix < tspec->size);
- *allctr = tspec->allctr[pref_ix];
- return pref_ix;
+ return tspec->allctr[pref_ix];
}
-static ERTS_INLINE void *
-get_used_allctr(void *extra, void *p, Allctr_t **allctr, UWord *sizep)
+/* SMP note:
+ * get_used_allctr() must be safe WITHOUT locking the allocator while
+ * concurrent threads may be updating adjacent blocks.
+ * We rely on getting a consistent result (without atomic op) when reading
+ * the block header word even if a concurrent thread is updating
+ * the "PREV_FREE" flag bit.
+ */
+static ERTS_INLINE Allctr_t*
+get_used_allctr(void *extra, void *p, UWord *sizep)
{
- ErtsAllocatorThrSpec_t *tspec = (ErtsAllocatorThrSpec_t *) extra;
- void *ptr = (void *) (((char *) p) - sizeof(UWord));
- UWord ainfo = *((UWord *) ptr);
- int aix = (int) (ainfo & ERTS_AU_PREF_ALLOC_IX_MASK);
- *allctr = tspec->allctr[aix];
- if (sizep)
- *sizep = ((ainfo >> ERTS_AU_PREF_ALLOC_BITS)
- & ERTS_AU_PREF_ALLOC_SIZE_MASK);
- return ptr;
-}
+ Block_t* blk = UMEM2BLK(p);
+ Carrier_t* crr = IS_SBC_BLK(blk) ? BLK2SBC(blk) : BLK2MBC(blk);
-static ERTS_INLINE void *
-put_used_allctr(void *p, int ix, UWord size)
-{
- UWord ainfo = (size >= ERTS_AU_PREF_ALLOC_SIZE_MASK
- ? ERTS_AU_PREF_ALLOC_SIZE_MASK
- : size);
- ainfo <<= ERTS_AU_PREF_ALLOC_BITS;
- ainfo |= (UWord) ix;
- *((UWord *) p) = ainfo;
- return (void *) (((char *) p) + sizeof(UWord));
+ if (sizep) {
+ *sizep = BLK_UMEM_SZ(blk);
+ }
+ return crr->allctr;
}
static void
@@ -1895,7 +1888,7 @@ create_sbmbc(Allctr_t *allctr, Uint umem_sz)
crr = erts_alloc(ERTS_ALC_T_SBMBC, crr_sz);
INC_CC(allctr->calls.sbmbc_alloc);
- SET_CARRIER_HDR(crr, crr_sz, SCH_SYS_ALLOC|SCH_MBC);
+ SET_CARRIER_HDR(crr, crr_sz, SCH_SYS_ALLOC|SCH_MBC, allctr);
blk = MBC2FBLK(allctr, crr);
@@ -2030,12 +2023,12 @@ create_carrier(Allctr_t *allctr, Uint umem_sz, UWord flags)
is_mseg = 1;
#endif
if (flags & CFLG_SBC) {
- SET_CARRIER_HDR(crr, crr_sz, SCH_MSEG|SCH_SBC);
+ SET_CARRIER_HDR(crr, crr_sz, SCH_MSEG|SCH_SBC, allctr);
STAT_MSEG_SBC_ALLOC(allctr, crr_sz, blk_sz);
goto sbc_final_touch;
}
else {
- SET_CARRIER_HDR(crr, crr_sz, SCH_MSEG|SCH_MBC);
+ SET_CARRIER_HDR(crr, crr_sz, SCH_MSEG|SCH_MBC, allctr);
STAT_MSEG_MBC_ALLOC(allctr, crr_sz);
goto mbc_final_touch;
}
@@ -2075,7 +2068,7 @@ create_carrier(Allctr_t *allctr, Uint umem_sz, UWord flags)
}
}
if (flags & CFLG_SBC) {
- SET_CARRIER_HDR(crr, crr_sz, SCH_SYS_ALLOC|SCH_SBC);
+ SET_CARRIER_HDR(crr, crr_sz, SCH_SYS_ALLOC|SCH_SBC, allctr);
STAT_SYS_ALLOC_SBC_ALLOC(allctr, crr_sz, blk_sz);
#if HAVE_ERTS_MSEG
@@ -2093,7 +2086,7 @@ create_carrier(Allctr_t *allctr, Uint umem_sz, UWord flags)
}
else {
- SET_CARRIER_HDR(crr, crr_sz, SCH_SYS_ALLOC|SCH_MBC);
+ SET_CARRIER_HDR(crr, crr_sz, SCH_SYS_ALLOC|SCH_MBC, allctr);
STAT_SYS_ALLOC_MBC_ALLOC(allctr, crr_sz);
#if HAVE_ERTS_MSEG
@@ -2144,7 +2137,7 @@ resize_carrier(Allctr_t *allctr, Block_t *old_blk, Uint umem_sz, UWord flags)
HARD_CHECK_BLK_CARRIER(allctr, old_blk);
old_blk_sz = SBC_BLK_SZ(old_blk);
- old_crr = BLK2SBC(allctr, old_blk);
+ old_crr = BLK2SBC(old_blk);
old_crr_sz = CARRIER_SZ(old_crr);
ASSERT(IS_SB_CARRIER(old_crr));
ASSERT(IS_SBC_BLK(old_blk));
@@ -2270,7 +2263,7 @@ destroy_carrier(Allctr_t *allctr, Block_t *blk)
if (IS_SBC_BLK(blk)) {
Uint blk_sz = SBC_BLK_SZ(blk);
- crr = BLK2SBC(allctr, blk);
+ crr = BLK2SBC(blk);
crr_sz = CARRIER_SZ(crr);
ASSERT(IS_LAST_BLK(blk));
@@ -3506,24 +3499,20 @@ erts_alcu_alloc_thr_spec(ErtsAlcType_t type, void *extra, Uint size)
void *
erts_alcu_alloc_thr_pref(ErtsAlcType_t type, void *extra, Uint size)
{
- int pref_ix;
Allctr_t *pref_allctr;
void *res;
- pref_ix = get_pref_allctr(extra, &pref_allctr);
+ pref_allctr = get_pref_allctr(extra);
if (pref_allctr->thread_safe)
erts_mtx_lock(&pref_allctr->mutex);
ERTS_ALCU_DBG_CHK_THR_ACCESS(pref_allctr);
- res = do_erts_alcu_alloc(type, pref_allctr, size + sizeof(UWord));
+ res = do_erts_alcu_alloc(type, pref_allctr, size);
if (pref_allctr->thread_safe)
erts_mtx_unlock(&pref_allctr->mutex);
- if (res)
- res = put_used_allctr(res, pref_ix, size);
-
DEBUG_CHECK_ALIGNMENT(res);
@@ -3644,21 +3633,20 @@ erts_alcu_free_thr_pref(ErtsAlcType_t type, void *extra, void *p)
{
if (p) {
Allctr_t *pref_allctr, *used_allctr;
- void *ptr;
- get_pref_allctr(extra, &pref_allctr);
- ptr = get_used_allctr(extra, p, &used_allctr, NULL);
+ pref_allctr = get_pref_allctr(extra);
+ used_allctr = get_used_allctr(extra, p, NULL);
if (pref_allctr != used_allctr)
enqueue_dealloc_other_instance(type,
used_allctr,
- ptr,
+ p,
(used_allctr->dd.ix
- pref_allctr->dd.ix));
else {
if (used_allctr->thread_safe)
erts_mtx_lock(&used_allctr->mutex);
ERTS_ALCU_DBG_CHK_THR_ACCESS(used_allctr);
- do_erts_alcu_free(type, used_allctr, ptr);
+ do_erts_alcu_free(type, used_allctr, p);
if (used_allctr->thread_safe)
erts_mtx_unlock(&used_allctr->mutex);
}
@@ -3745,7 +3733,7 @@ do_erts_alcu_realloc(ErtsAlcType_t type,
Uint crr_sz_val;
#if HAVE_ERTS_MSEG
- if (IS_SYS_ALLOC_CARRIER(BLK2SBC(allctr, blk)))
+ if (IS_SYS_ALLOC_CARRIER(BLK2SBC(blk)))
#endif
crr_sz = SYS_ALLOC_CARRIER_CEILING(used_sz);
#if HAVE_ERTS_MSEG
@@ -3962,16 +3950,15 @@ static ERTS_INLINE void *
realloc_thr_pref(ErtsAlcType_t type, void *extra, void *p, Uint size,
int force_move)
{
- int pref_ix;
- void *ptr, *res;
+ void *res;
Allctr_t *pref_allctr, *used_allctr;
UWord old_user_size;
if (!p)
return erts_alcu_alloc_thr_pref(type, extra, size);
- pref_ix = get_pref_allctr(extra, &pref_allctr);
- ptr = get_used_allctr(extra, p, &used_allctr, &old_user_size);
+ pref_allctr = get_pref_allctr(extra);
+ used_allctr = get_used_allctr(extra, p, &old_user_size);
ASSERT(used_allctr && pref_allctr);
@@ -3981,56 +3968,33 @@ realloc_thr_pref(ErtsAlcType_t type, void *extra, void *p, Uint size,
ERTS_ALCU_DBG_CHK_THR_ACCESS(used_allctr);
res = do_erts_alcu_realloc(type,
used_allctr,
- ptr,
- size + sizeof(UWord),
+ p,
+ size,
0);
if (used_allctr->thread_safe)
erts_mtx_unlock(&used_allctr->mutex);
- if (res)
- res = put_used_allctr(res, pref_ix, size);
}
else {
if (pref_allctr->thread_safe)
erts_mtx_lock(&pref_allctr->mutex);
- res = do_erts_alcu_alloc(type, pref_allctr, size + sizeof(UWord));
- if (pref_allctr->thread_safe && (!force_move
- || used_allctr != pref_allctr))
+ res = do_erts_alcu_alloc(type, pref_allctr, size);
+ if (pref_allctr->thread_safe && used_allctr != pref_allctr) {
erts_mtx_unlock(&pref_allctr->mutex);
+ }
if (res) {
- Block_t *blk;
- size_t cpy_size;
-
- res = put_used_allctr(res, pref_ix, size);
-
DEBUG_CHECK_ALIGNMENT(res);
- blk = UMEM2BLK(ptr);
- if (old_user_size != ERTS_AU_PREF_ALLOC_SIZE_MASK)
- cpy_size = old_user_size;
- else {
- if (used_allctr->thread_safe && (!force_move
- || used_allctr != pref_allctr))
- erts_mtx_lock(&used_allctr->mutex);
- ERTS_SMP_LC_ASSERT(!used_allctr->thread_safe ||
- erts_lc_mtx_is_locked(&used_allctr->mutex));
- cpy_size = BLK_SZ(blk);
- if (used_allctr->thread_safe && (!force_move
- || used_allctr != pref_allctr))
- erts_mtx_unlock(&used_allctr->mutex);
- cpy_size -= ABLK_HDR_SZ + sizeof(UWord);
- }
- if (cpy_size > size)
- cpy_size = size;
- sys_memcpy(res, p, cpy_size);
+ sys_memcpy(res, p, MIN(size,old_user_size));
- if (!force_move || used_allctr != pref_allctr)
+ if (used_allctr != pref_allctr) {
enqueue_dealloc_other_instance(type,
used_allctr,
- ptr,
+ p,
(used_allctr->dd.ix
- pref_allctr->dd.ix));
+ }
else {
- do_erts_alcu_free(type, used_allctr, ptr);
+ do_erts_alcu_free(type, used_allctr, p);
ASSERT(pref_allctr == used_allctr);
if (pref_allctr->thread_safe)
erts_mtx_unlock(&pref_allctr->mutex);
@@ -4208,35 +4172,16 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init)
#ifdef ERTS_SMP
allctr->dd.use = 0;
if (init->tpref) {
- allctr->mbc_header_size = (UNIT_CEILING(allctr->mbc_header_size
- + FBLK_FTR_SZ
- + ABLK_HDR_SZ
- + sizeof(UWord))
- - ABLK_HDR_SZ
- - sizeof(UWord));
- allctr->sbc_header_size = (UNIT_CEILING(sizeof(Carrier_t)
- + FBLK_FTR_SZ
- + ABLK_HDR_SZ
- + sizeof(UWord))
- - ABLK_HDR_SZ
- - sizeof(UWord));
-
allctr->dd.use = 1;
init_dd_queue(&allctr->dd.q);
allctr->dd.ix = init->ix;
}
- else
#endif
- {
- allctr->mbc_header_size = (UNIT_CEILING(allctr->mbc_header_size
- + FBLK_FTR_SZ
- + ABLK_HDR_SZ)
- - ABLK_HDR_SZ);
- allctr->sbc_header_size = (UNIT_CEILING(sizeof(Carrier_t)
- + FBLK_FTR_SZ
- + ABLK_HDR_SZ)
- - ABLK_HDR_SZ);
- }
+ allctr->mbc_header_size = (UNIT_CEILING(allctr->mbc_header_size
+ + FBLK_FTR_SZ
+ + ABLK_HDR_SZ)
+ - ABLK_HDR_SZ);
+ allctr->sbc_header_size = SIZEOF_SBC_HDR;
if (allctr->main_carrier_size) {
Block_t *blk;
@@ -4362,8 +4307,7 @@ erts_alcu_test(unsigned long op, unsigned long a1, unsigned long a2)
case 0x00b: return (unsigned long) CARRIER_SZ((Carrier_t *) a1);
case 0x00c: return (unsigned long) SBC2BLK((Allctr_t *) a1,
(Carrier_t *) a2);
- case 0x00d: return (unsigned long) BLK2SBC((Allctr_t *) a1,
- (Block_t *) a2);
+ case 0x00d: return (unsigned long) BLK2SBC((Block_t *) a2);
case 0x00e: return (unsigned long) MBC2FBLK((Allctr_t *) a1,
(Carrier_t *) a2);
case 0x00f: return (unsigned long) FBLK2MBC((Allctr_t *) a1,
@@ -4438,7 +4382,7 @@ check_blk_carrier(Allctr_t *allctr, Block_t *iblk)
CarrierList_t *cl;
if (IS_SBC_BLK(iblk)) {
- Carrier_t *sbc = BLK2SBC(allctr, iblk);
+ Carrier_t *sbc = BLK2SBC(iblk);
ASSERT(SBC2BLK(allctr, sbc) == iblk);
ASSERT(CARRIER_SZ(sbc) - allctr->sbc_header_size >= SBC_BLK_SZ(iblk));
diff --git a/erts/emulator/beam/erl_alloc_util.h b/erts/emulator/beam/erl_alloc_util.h
index 1e6ba5736a..7d6f61fdff 100644
--- a/erts/emulator/beam/erl_alloc_util.h
+++ b/erts/emulator/beam/erl_alloc_util.h
@@ -245,6 +245,7 @@ struct Carrier_t_ {
UWord chdr;
Carrier_t *next;
Carrier_t *prev;
+ Allctr_t *allctr;
};
typedef struct {