kiper220/mimalloc
1
0
Fork 0
mirror of https://github.com/microsoft/mimalloc.git synced 2025-05-05 15:09:31 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

use hinted address to mmap to reduce mmap calls

Browse source
This commit is contained in:
daan 2019-07-21 17:08:09 -07:00
parent df33efb19a
commit 069f52523f
1 changed files with 23 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
src/os.c
View file

@ -10,6 +10,7 @@ terms of the MIT license. A copy of the license can be found in the file
#include "mimalloc.h" #include "mimalloc.h"
#include "mimalloc-internal.h" #include "mimalloc-internal.h"
#include "mimalloc-atomic.h"
#include <string.h> // memset #include <string.h> // memset
#include <errno.h> #include <errno.h>
@ -242,6 +243,23 @@ static void* mi_wasm_heap_grow(size_t size, size_t try_alignment) {
return (void*) aligned_base; return (void*) aligned_base;
} }
#else #else
static void* mi_unix_mmapx(size_t size, size_t try_alignment, int protect_flags, int flags, int fd) {
void* p = NULL;
#if (MI_INTPTR_SIZE >= 8) && !defined(MAP_ALIGNED)
// on 64-bit systems, use a special area for 4MiB aligned allocations
static volatile intptr_t aligned_base = ((intptr_t)1 << 42); // starting at 4TiB
if (try_alignment <= MI_SEGMENT_SIZE && (size%MI_SEGMENT_SIZE)==0 && (aligned_base%try_alignment)==0) {
intptr_t hint = mi_atomic_add(&aligned_base,size) - size;
p = mmap((void*)hint,size,protect_flags,flags,fd,0);
if (p==MAP_FAILED) p = NULL; // fall back to regular mmap
}
#endif
if (p==NULL) {
p = mmap(NULL,size,protect_flags,flags,fd,0);
}
return p;
}
static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags) { static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags) {
void* p = NULL; void* p = NULL;
#if !defined(MAP_ANONYMOUS) #if !defined(MAP_ANONYMOUS)
@ -278,12 +296,12 @@ static void* mi_unix_mmap(size_t size, size_t try_alignment, int protect_flags)
// try large page allocation // try large page allocation
// TODO: if always failing due to permissions or no huge pages, try to avoid repeatedly trying? // TODO: if always failing due to permissions or no huge pages, try to avoid repeatedly trying?
// Should we check this in _mi_os_init? (as on Windows) // Should we check this in _mi_os_init? (as on Windows)
p = mmap(NULL, size, protect_flags, lflags, fd, 0); p = mi_unix_mmapx(size, try_alignment, protect_flags, lflags, fd);
if (p == MAP_FAILED) p = NULL; // fall back to regular mmap if large is exhausted or no permission if (p == MAP_FAILED) p = NULL; // fall back to regular mmap if large is exhausted or no permission
} }
} }
if (p == NULL) { if (p == NULL) {
p = mmap(NULL, size, protect_flags, flags, -1, 0); p = mi_unix_mmapx(size, try_alignment, protect_flags, flags, -1);
if (p == MAP_FAILED) p = NULL; if (p == MAP_FAILED) p = NULL;
} }
return p; return p;