/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2003-2011. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
/*
* Description: A "good fit" allocator. Segregated free-lists with a
* maximum search depth are used in order to find a good
* fit fast. Each free-list contains blocks of sizes in a
* specific range. First the free-list
* covering the desired size is searched if it is not empty.
* This search is stopped when the maximum search depth has
* been reached. If no free block was found in the free-list
* covering the desired size, the next non-empty free-list
* covering larger sizes is searched. The maximum search
* depth is by default 3. The insert and delete operations
* are O(1) and the search operation is O(n) where n is the
* maximum search depth, i.e. by default the all operations
* are O(1).
*
* This module is a callback-module for erl_alloc_util.c
*
* Author: Rickard Green
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "global.h"
#define GET_ERL_GF_ALLOC_IMPL
#include "erl_goodfit_alloc.h"
#define MIN_MBC_SZ (16*1024)
#define MIN_MBC_FIRST_FREE_SZ (4*1024)
#define MAX_SUB_MASK_IX \
((((UWord)1) << (NO_OF_BKT_IX_BITS - SUB_MASK_IX_SHIFT)) - 1)
#define MAX_SUB_BKT_IX ((((UWord)1) << SUB_MASK_IX_SHIFT) - 1)
#define MAX_BKT_IX (NO_OF_BKTS - 1)
#define MIN_BLK_SZ UNIT_CEILING(sizeof(GFFreeBlock_t) + sizeof(UWord))
#define IX2SBIX(IX) ((IX) & (~(~((UWord)0) << SUB_MASK_IX_SHIFT)))
#define IX2SMIX(IX) ((IX) >> SUB_MASK_IX_SHIFT)
#define MAKE_BKT_IX(SMIX, SBIX) \
((((UWord)(SMIX)) << SUB_MASK_IX_SHIFT) | ((UWord)(SBIX)))
#define SET_BKT_MASK_IX(BM, IX) \
do { \
int sub_mask_ix__ = IX2SMIX((IX)); \
(BM).main |= (((UWord) 1) << sub_mask_ix__); \
(BM).sub[sub_mask_ix__] |= (((UWord)1) << IX2SBIX((IX))); \
} while (0)
#define UNSET_BKT_MASK_IX(BM, IX) \
do { \
int sub_mask_ix__ = IX2SMIX((IX)); \
(BM).sub[sub_mask_ix__] &= ~(((UWord)1) << IX2SBIX((IX))); \
if (!(BM).sub[sub_mask_ix__]) \
(BM).main &= ~(((UWord)1) << sub_mask_ix__); \
} while (0)
/* Buckets ... */
#define BKT_INTRVL_A (1*sizeof(Unit_t))
#define BKT_INTRVL_B (16*sizeof(Unit_t))
#define BKT_INTRVL_C (96*sizeof(Unit_t))
#define BKT_MIN_SIZE_A MIN_BLK_SZ
#define BKT_MIN_SIZE_B (BKT_MAX_SIZE_A + 1)
#define BKT_MIN_SIZE_C (BKT_MAX_SIZE_B + 1)
#define BKT_MIN_SIZE_D (BKT_MAX_SIZE_C + 1)
#define BKT_MAX_SIZE_A ((NO_OF_BKTS/4)*BKT_INTRVL_A+BKT_MIN_SIZE_A-1)
#define BKT_MAX_SIZE_B ((NO_OF_BKTS/4)*BKT_INTRVL_B+BKT_MIN_SIZE_B-1)
#define BKT_MAX_SIZE_C ((NO_OF_BKTS/4)*BKT_INTRVL_C+BKT_MIN_SIZE_C-1)
#define BKT_MAX_IX_A ((NO_OF_BKTS*1)/4 - 1)
#define BKT_MAX_IX_B ((NO_OF_BKTS*2)/4 - 1)
#define BKT_MAX_IX_C ((NO_OF_BKTS*3)/4 - 1)
#define BKT_MAX_IX_D ((NO_OF_BKTS*4)/4 - 1)
#define BKT_MIN_IX_A (0)
#define BKT_MIN_IX_B (BKT_MAX_IX_A + 1)
#define BKT_MIN_IX_C (BKT_MAX_IX_B + 1)
#define BKT_MIN_IX_D (BKT_MAX_IX_C + 1)
#define BKT_IX_(BAP, SZ) \
((SZ) <= BKT_MAX_SIZE_A \
? (((SZ) - BKT_MIN_SIZE_A)/BKT_INTRVL_A + BKT_MIN_IX_A) \
: ((SZ) <= BKT_MAX_SIZE_B \
? (((SZ) - BKT_MIN_SIZE_B)/BKT_INTRVL_B + BKT_MIN_IX_B) \
: ((SZ) <= BKT_MAX_SIZE_C \
? (((SZ) - BKT_MIN_SIZE_C)/BKT_INTRVL_C + BKT_MIN_IX_C) \
: ((SZ) <= (BAP)->bkt_max_size_d \
? (((SZ) - BKT_MIN_SIZE_D)/(BAP)->bkt_intrvl_d + BKT_MIN_IX_D)\
: (NO_OF_BKTS - 1)))))
#define BKT_MIN_SZ_(BAP, IX) \
((IX) <= BKT_MAX_IX_A \
? (((IX) - BKT_MIN_IX_A)*BKT_INTRVL_A + BKT_MIN_SIZE_A) \
: ((IX) <= BKT_MAX_IX_B \
? (((IX) - BKT_MIN_IX_B)*BKT_INTRVL_B + BKT_MIN_SIZE_B) \
: ((IX) <= BKT_MAX_IX_C \
? (((IX) - BKT_MIN_IX_C)*BKT_INTRVL_C + BKT_MIN_SIZE_C) \
: (((IX) - BKT_MIN_IX_D)*(BAP)->bkt_intrvl_d + BKT_MIN_SIZE_D))))
#ifdef DEBUG
static int
BKT_IX(GFAllctr_t *gfallctr, Uint size)
{
int ix;
ASSERT(size >= MIN_BLK_SZ);
ix = BKT_IX_(gfallctr, size);
ASSERT(0 <= ix && ix <= BKT_MAX_IX_D);
return ix;
}
static Uint
BKT_MIN_SZ(GFAllctr_t *gfallctr, int ix)
{
Uint size;
ASSERT(0 <= ix && ix <= BKT_MAX_IX_D);
size = BKT_MIN_SZ_(gfallctr, ix);
#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
ASSERT(ix == BKT_IX(gfallctr, size));
ASSERT(size == MIN_BLK_SZ || ix - 1 == BKT_IX(gfallctr, size - 1));
#endif
return size;
}
#else
#define BKT_IX BKT_IX_
#define BKT_MIN_SZ BKT_MIN_SZ_
#endif
/* Prototypes of callback functions */
static Block_t * get_free_block (Allctr_t *, Uint,
Block_t *, Uint, Uint32);
static void link_free_block (Allctr_t *, Block_t *, Uint32);
static void unlink_free_block (Allctr_t *, Block_t *, Uint32);
static void update_last_aux_mbc (Allctr_t *, Carrier_t *, Uint32);
static Eterm info_options (Allctr_t *, char *, int *,
void *, Uint **, Uint *);
static void init_atoms (void);
#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
static void check_block (Allctr_t *, Block_t *, int);
static void check_mbc (Allctr_t *, Carrier_t *);
#endif
static int atoms_initialized = 0;
void
erts_gfalc_init(void)
{
atoms_initialized = 0;
}
Allctr_t *
erts_gfalc_start(GFAllctr_t *gfallctr,
GFAllctrInit_t *gfinit,
AllctrInit_t *init)
{
struct {
int dummy;
GFAllctr_t allctr;
} zero = {0};
/* The struct with a dummy element first is used in order to avoid (an
incorrect) gcc warning. gcc warns if {0} is used as initializer of
a struct when the first member is a struct (not if, for example,
the third member is a struct). */
Allctr_t *allctr = (Allctr_t *) gfallctr;
sys_memcpy((void *) gfallctr, (void *) &zero.allctr, sizeof(GFAllctr_t));
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);
allctr->vsn_str = ERTS_ALC_GF_ALLOC_VSN_STR;
/* Callback functions */
allctr->get_free_block = get_free_block;
allctr->link_free_block = link_free_block;
allctr->unlink_free_block = unlink_free_block;
allctr->info_options = info_options;
allctr->get_next_mbc_size = NULL;
allctr->creating_mbc = update_last_aux_mbc;
allctr->destroying_mbc = update_last_aux_mbc;
allctr->init_atoms = init_atoms;
#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
allctr->check_block = check_block;
allctr->check_mbc = check_mbc;
#endif
allctr->atoms_initialized = 0;
if (init->sbct > BKT_MIN_SIZE_D-1)
gfallctr->bkt_intrvl_d =
UNIT_CEILING(((3*(init->sbct - BKT_MIN_SIZE_D - 1)
/(NO_OF_BKTS/4 - 1)) + 1)
/ 2);
if (gfallctr->bkt_intrvl_d < BKT_INTRVL_C)
gfallctr->bkt_intrvl_d = BKT_INTRVL_C;
gfallctr->bkt_max_size_d = ((NO_OF_BKTS/4)*gfallctr->bkt_intrvl_d
+ BKT_MIN_SIZE_D
- 1);
gfallctr->max_blk_search = (Uint) MAX(1, gfinit->mbsd);
if (!erts_alcu_start(allctr, init))
return NULL;
if (allctr->min_block_size != MIN_BLK_SZ)
return NULL;
return allctr;
}
static int
find_bucket(BucketMask_t *bmask, int min_index)
{
int min, mid, max;
int sub_mask_ix, sub_bkt_ix;
int ix = -1;
#undef GET_MIN_BIT
#define GET_MIN_BIT(MinBit, BitMask, Min, Max) \
min = (Min); \
max = (Max); \
while(max != min) { \
mid = ((max - min) >> 1) + min; \
if((BitMask) \
& (~(~((UWord) 0) << (mid + 1))) \
& (~((UWord) 0) << min)) \
max = mid; \
else \
min = mid + 1; \
} \
(MinBit) = min
ASSERT(bmask->main < (((UWord) 1) << (MAX_SUB_MASK_IX+1)));
sub_mask_ix = IX2SMIX(min_index);
if ((bmask->main & (~((UWord) 0) << sub_mask_ix)) == 0)
return -1;
/* There exists a non empty bucket; find it... */
if (bmask->main & (((UWord) 1) << sub_mask_ix)) {
sub_bkt_ix = IX2SBIX(min_index);
if ((bmask->sub[sub_mask_ix] & (~((UWord) 0) << sub_bkt_ix)) == 0) {
sub_mask_ix++;
sub_bkt_ix = 0;
if ((bmask->main & (~((UWord) 0)<< sub_mask_ix)) == 0)
return -1;
}
else
goto find_sub_bkt_ix;
}
else {
sub_mask_ix++;
sub_bkt_ix = 0;
}
ASSERT(sub_mask_ix <= MAX_SUB_MASK_IX);
/* Has to be a bit > sub_mask_ix */
ASSERT(bmask->main & (~((UWord) 0) << (sub_mask_ix)));
GET_MIN_BIT(sub_mask_ix, bmask->main, sub_mask_ix, MAX_SUB_MASK_IX);
find_sub_bkt_ix:
ASSERT(sub_mask_ix <= MAX_SUB_MASK_IX);
ASSERT(sub_bkt_ix <= MAX_SUB_BKT_IX);
if ((bmask->sub[sub_mask_ix] & (((UWord) 1) << sub_bkt_ix)) == 0) {
ASSERT(sub_mask_ix + 1 <= MAX_SUB_BKT_IX);
/* Has to be a bit > sub_bkt_ix */
ASSERT(bmask->sub[sub_mask_ix] & (~((UWord) 0) << sub_bkt_ix));
GET_MIN_BIT(sub_bkt_ix,
bmask->sub[sub_mask_ix],
sub_bkt_ix+1,
MAX_SUB_BKT_IX);
ASSERT(sub_bkt_ix <= MAX_SUB_BKT_IX);
}
ix = MAKE_BKT_IX(sub_mask_ix, sub_bkt_ix);
ASSERT(0 <= ix && ix < NO_OF_BKTS);
return ix;
#undef GET_MIN_BIT
}
static Block_t *
search_bucket(Allctr_t *allctr, int ix, Uint size)
{
int i;
Uint min_sz;
Uint blk_sz;
Uint cand_sz = 0;
UWord max_blk_search;
GFFreeBlock_t *blk;
GFFreeBlock_t *cand = NULL;
int blk_on_lambc;
int cand_on_lambc = 0;
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
ASSERT(0 <= ix && ix <= NO_OF_BKTS - 1);
if (!gfallctr->buckets[ix])
return NULL;
min_sz = BKT_MIN_SZ(gfallctr, ix);
if (min_sz < size)
min_sz = size;
max_blk_search = gfallctr->max_blk_search;
for (blk = gfallctr->buckets[ix], i = 0;
blk && i < max_blk_search;
blk = blk->next, i++) {
blk_sz = MBC_FBLK_SZ(&blk->block_head);
blk_on_lambc = (((char *) blk) < gfallctr->last_aux_mbc_end
&& gfallctr->last_aux_mbc_start <= ((char *) blk));
if (blk_sz == min_sz && !blk_on_lambc)
return (Block_t *) blk;
if (blk_sz >= min_sz
&& (!cand
|| (!blk_on_lambc && (cand_on_lambc || blk_sz < cand_sz))
|| (blk_on_lambc && cand_on_lambc && blk_sz < cand_sz))) {
cand_sz = blk_sz;
cand = blk;
cand_on_lambc = blk_on_lambc;
}
}
return (Block_t *) cand;
}
static Block_t *
get_free_block(Allctr_t *allctr, Uint size,
Block_t *cand_blk, Uint cand_size, Uint32 flags)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
int unsafe_bi, min_bi;
Block_t *blk;
ASSERT(!cand_blk || cand_size >= size);
unsafe_bi = BKT_IX(gfallctr, size);
min_bi = find_bucket(&gfallctr->bucket_mask, unsafe_bi);
if (min_bi < 0)
return NULL;
if (min_bi == unsafe_bi) {
blk = search_bucket(allctr, min_bi, size);
if (blk) {
if (cand_blk && cand_size <= MBC_FBLK_SZ(blk))
return NULL; /* cand_blk was better */
unlink_free_block(allctr, blk, flags);
return blk;
}
if (min_bi < NO_OF_BKTS - 1) {
min_bi = find_bucket(&gfallctr->bucket_mask, min_bi + 1);
if (min_bi < 0)
return NULL;
}
else
return NULL;
}
else {
ASSERT(min_bi > unsafe_bi);
}
/* We are guaranteed to find a block that fits in this bucket */
blk = search_bucket(allctr, min_bi, size);
ASSERT(blk);
if (cand_blk && cand_size <= MBC_FBLK_SZ(blk))
return NULL; /* cand_blk was better */
unlink_free_block(allctr, blk, flags);
return blk;
}
static void
link_free_block(Allctr_t *allctr, Block_t *block, Uint32 flags)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
GFFreeBlock_t *blk = (GFFreeBlock_t *) block;
Uint sz = MBC_FBLK_SZ(&blk->block_head);
int i = BKT_IX(gfallctr, sz);
ASSERT(sz >= MIN_BLK_SZ);
SET_BKT_MASK_IX(gfallctr->bucket_mask, i);
blk->prev = NULL;
blk->next = gfallctr->buckets[i];
if (blk->next) {
ASSERT(!blk->next->prev);
blk->next->prev = blk;
}
gfallctr->buckets[i] = blk;
}
static void
unlink_free_block(Allctr_t *allctr, Block_t *block, Uint32 flags)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
GFFreeBlock_t *blk = (GFFreeBlock_t *) block;
Uint sz = MBC_FBLK_SZ(&blk->block_head);
int i = BKT_IX(gfallctr, sz);
if (!blk->prev) {
ASSERT(gfallctr->buckets[i] == blk);
gfallctr->buckets[i] = blk->next;
}
else
blk->prev->next = blk->next;
if (blk->next)
blk->next->prev = blk->prev;
if (!gfallctr->buckets[i])
UNSET_BKT_MASK_IX(gfallctr->bucket_mask, i);
}
static void
update_last_aux_mbc(Allctr_t *allctr, Carrier_t *mbc, Uint32 flags)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
if (gfallctr->last_aux_mbc_start != (char *) allctr->mbc_list.last) {
if (allctr->mbc_list.last
&& allctr->main_carrier != allctr->mbc_list.last) {
gfallctr->last_aux_mbc_start = (char *) allctr->mbc_list.last;
gfallctr->last_aux_mbc_end = (((char *) allctr->mbc_list.last)
+ CARRIER_SZ(allctr->mbc_list.last));
}
else {
gfallctr->last_aux_mbc_start = NULL;
gfallctr->last_aux_mbc_end = NULL;
}
}
}
static struct {
Eterm mbsd;
Eterm as;
Eterm gf;
#ifdef DEBUG
Eterm end_of_atoms;
#endif
} am;
static void ERTS_INLINE atom_init(Eterm *atom, char *name)
{
*atom = am_atom_put(name, strlen(name));
}
#define AM_INIT(AM) atom_init(&am.AM, #AM)
static void
init_atoms(void)
{
#ifdef DEBUG
Eterm *atom;
#endif
if (atoms_initialized)
return;
#ifdef DEBUG
for (atom = (Eterm *) &am; atom <= &am.end_of_atoms; atom++) {
*atom = THE_NON_VALUE;
}
#endif
AM_INIT(mbsd);
AM_INIT(as);
AM_INIT(gf);
#ifdef DEBUG
for (atom = (Eterm *) &am; atom < &am.end_of_atoms; atom++) {
ASSERT(*atom != THE_NON_VALUE);
}
#endif
atoms_initialized = 1;
}
#define bld_uint erts_bld_uint
#define bld_cons erts_bld_cons
#define bld_tuple erts_bld_tuple
static ERTS_INLINE void
add_2tup(Uint **hpp, Uint *szp, Eterm *lp, Eterm el1, Eterm el2)
{
*lp = bld_cons(hpp, szp, bld_tuple(hpp, szp, 2, el1, el2), *lp);
}
static Eterm
info_options(Allctr_t *allctr,
char *prefix,
int *print_to_p,
void *print_to_arg,
Uint **hpp,
Uint *szp)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
Eterm res = THE_NON_VALUE;
if (print_to_p) {
erts_print(*print_to_p,
print_to_arg,
"%smbsd: %lu\n"
"%sas: gf\n",
prefix, gfallctr->max_blk_search,
prefix);
}
if (hpp || szp) {
if (!atoms_initialized)
erl_exit(1, "%s:%d: Internal error: Atoms not initialized",
__FILE__, __LINE__);;
res = NIL;
add_2tup(hpp, szp, &res, am.as, am.gf);
add_2tup(hpp, szp, &res,
am.mbsd,
bld_uint(hpp, szp, gfallctr->max_blk_search));
}
return res;
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
* NOTE: erts_gfalc_test() is only supposed to be used for testing. *
* *
* Keep alloc_SUITE_data/allocator_test.h updated if changes are made *
* to erts_gfalc_test() *
\* */
unsigned long
erts_gfalc_test(unsigned long op, unsigned long a1, unsigned long a2)
{
switch (op) {
case 0x100: return (unsigned long) BKT_IX((GFAllctr_t *) a1, (Uint) a2);
case 0x101: return (unsigned long) BKT_MIN_SZ((GFAllctr_t *) a1, (int) a2);
case 0x102: return (unsigned long) NO_OF_BKTS;
case 0x103: return (unsigned long)
find_bucket(&((GFAllctr_t *) a1)->bucket_mask, (int) a2);
default: ASSERT(0); return ~((unsigned long) 0);
}
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
* Debug functions *
\* */
#ifdef ERTS_ALLOC_UTIL_HARD_DEBUG
void
check_block(Allctr_t *allctr, Block_t * blk, int free_block)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
int i;
int bi;
int found;
GFFreeBlock_t *fblk;
if(free_block) {
Uint blk_sz = is_sbc_blk(blk) ? SBC_BLK_SZ(blk) : MBC_BLK_SZ(blk);
bi = BKT_IX(gfallctr, blk_sz);
ASSERT(gfallctr->bucket_mask.main & (((UWord) 1) << IX2SMIX(bi)));
ASSERT(gfallctr->bucket_mask.sub[IX2SMIX(bi)]
& (((UWord) 1) << IX2SBIX(bi)));
found = 0;
for (fblk = gfallctr->buckets[bi]; fblk; fblk = fblk->next)
if (blk == (Block_t *) fblk)
found++;
ASSERT(found == 1);
}
else
bi = -1;
found = 0;
for (i = 0; i < NO_OF_BKTS; i++) {
if (i == bi)
continue; /* Already checked */
for (fblk = gfallctr->buckets[i]; fblk; fblk = fblk->next)
if (blk == (Block_t *) fblk)
found++;
}
ASSERT(found == 0);
}
void
check_mbc(Allctr_t *allctr, Carrier_t *mbc)
{
GFAllctr_t *gfallctr = (GFAllctr_t *) allctr;
int bi;
for(bi = 0; bi < NO_OF_BKTS; bi++) {
if ((gfallctr->bucket_mask.main & (((UWord) 1) << IX2SMIX(bi)))
&& (gfallctr->bucket_mask.sub[IX2SMIX(bi)]
& (((UWord) 1) << IX2SBIX(bi)))) {
ASSERT(gfallctr->buckets[bi] != NULL);
}
else {
ASSERT(gfallctr->buckets[bi] == NULL);
}
}
}
#endif