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authorBjörn-Egil Dahlberg <[email protected]>2012-11-01 15:41:00 +0100
committerSverker Eriksson <[email protected]>2012-11-13 19:51:11 +0100
commitc3762df91e6ccc322a08456d429ceb856316aae7 (patch)
tree02c74904efa9a1e39190243cd146e9055854d300 /erts
parent8d4210b25a791c37deca8a37b14565fd6fad2d1f (diff)
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erts: Let mseg allocate larger alignments
Diffstat (limited to 'erts')
-rw-r--r--erts/emulator/sys/common/erl_mseg.c59
1 files changed, 51 insertions, 8 deletions
diff --git a/erts/emulator/sys/common/erl_mseg.c b/erts/emulator/sys/common/erl_mseg.c
index 1235a32e8c..e77287f2ef 100644
--- a/erts/emulator/sys/common/erl_mseg.c
+++ b/erts/emulator/sys/common/erl_mseg.c
@@ -57,6 +57,9 @@
/* Implement some other way to get the real page size if needed! */
#endif
+#define ALIGN_BITS (14)
+#define ALIGNED_SIZE (1 << ALIGN_BITS) /* 16kB */
+
#define MAX_CACHE_SIZE 30
#undef MIN
@@ -71,6 +74,12 @@
#define PAGE_CEILING(X) PAGE_FLOOR((X) + INV_PAGE_MASK)
#define PAGES(X) ((X) >> page_shift)
+#define INV_ALIGNED_MASK ((Uint) ((ALIGNED_SIZE) - 1))
+#define ALIGNED_MASK (~INV_ALIGNED_MASK)
+#define ALIGNED_FLOOR(X) (((Uint)(X)) & ALIGNED_MASK)
+#define ALIGNED_CEILING(X) ALIGNED_FLOOR((X) + INV_ALIGNED_MASK)
+#define MAP_IS_ALIGNED(X) ((((Uint)X) & (ALIGNED_SIZE - 1)) == 0)
+
static int atoms_initialized;
typedef struct mem_kind_t MemKind;
@@ -323,11 +332,44 @@ schedule_cache_check(ErtsMsegAllctr_t *ma)
}
static ERTS_INLINE void *
+mmap_align(void *addr, size_t length, int prot, int flags, int fd, off_t offset) {
+
+ void *seg, *aseg;
+ Uint diff;
+
+ seg = mmap(addr, length, prot, flags, fd, offset);
+
+ if (MAP_IS_ALIGNED(seg) || seg == MAP_FAILED) {
+ return seg;
+ }
+
+ munmap(seg, length);
+
+ seg = mmap(addr, length + ALIGNED_SIZE, prot, flags, fd, offset);
+ if (seg == MAP_FAILED) {
+ return seg;
+ }
+
+ /* ceil to aligned pointer */
+ aseg = (void *)(((Uint)(seg + ALIGNED_SIZE)) & (~(ALIGNED_SIZE - 1)));
+ diff = aseg - seg;
+
+ if (diff > 0) {
+ munmap(seg, diff);
+ }
+
+ if (ALIGNED_SIZE - diff > 0) {
+ munmap((void *) (aseg + length), ALIGNED_SIZE - diff);
+ }
+
+ return aseg;
+}
+
+static ERTS_INLINE void *
mseg_create(ErtsMsegAllctr_t *ma, MemKind* mk, Uint size)
{
void *seg;
-
- ASSERT(size % page_size == 0);
+ ASSERT(size % ALIGNED_SIZE == 0);
#if HALFWORD_HEAP
if (mk == &ma->low_mem) {
@@ -342,7 +384,7 @@ mseg_create(ErtsMsegAllctr_t *ma, MemKind* mk, Uint size)
{
#if HAVE_MMAP
{
- seg = (void *) mmap((void *) 0, (size_t) size,
+ seg = (void *) mmap_align((void *) 0, (size_t) size,
MMAP_PROT, MMAP_FLAGS, MMAP_FD, 0);
if (seg == (void *) MAP_FAILED)
seg = NULL;
@@ -358,8 +400,7 @@ mseg_create(ErtsMsegAllctr_t *ma, MemKind* mk, Uint size)
}
static ERTS_INLINE void
-mseg_destroy(ErtsMsegAllctr_t *ma, MemKind* mk, void *seg, Uint size)
-{
+mseg_destroy(ErtsMsegAllctr_t *ma, MemKind* mk, void *seg, Uint size) {
#ifdef DEBUG
int res;
#endif
@@ -651,7 +692,7 @@ mseg_alloc(ErtsMsegAllctr_t *ma, ErtsAlcType_t atype, Uint *size_p,
INC_CC(ma, alloc);
- size = PAGE_CEILING(*size_p);
+ size = ALIGNED_CEILING(*size_p);
#if CAN_PARTLY_DESTROY
if (size < ma->min_seg_size)
@@ -837,7 +878,7 @@ mseg_realloc(ErtsMsegAllctr_t *ma, ErtsAlcType_t atype, void *seg,
mk = memkind(ma, opt);
new_seg = seg;
- new_size = PAGE_CEILING(*new_size_p);
+ new_size = ALIGNED_CEILING(*new_size_p);
if (new_size == old_size)
;
@@ -1478,7 +1519,7 @@ erts_mseg_no(const ErtsMsegOpt_t *opt)
Uint
erts_mseg_unit_size(void)
{
- return page_size;
+ return ALIGNED_SIZE;
}
static void mem_kind_init(ErtsMsegAllctr_t *ma, MemKind* mk, const char* name)
@@ -1553,8 +1594,10 @@ erts_mseg_init(ErtsMsegInit_t *init)
#endif
page_size = GET_PAGE_SIZE;
+ ASSERT( (ALIGNED_SIZE % page_size) == 0);
page_shift = 1;
+ /* page size alignment assertion */
while ((page_size >> page_shift) != 1) {
if ((page_size & (1 << (page_shift - 1))) != 0)
erl_exit(ERTS_ABORT_EXIT,