提交 e5d78fe8 编写于 作者: R Rich Felker

fix issue with excessive mremap syscalls on realloc

CHUNK_SIZE macro was defined incorrectly and shaving off at least one
significant bit in the size of mmapped chunks, resulting in the test
for oldlen==newlen always failing and incurring a syscall. fortunately
i don't think this issue caused any other observable behavior; the
definition worked correctly for all non-mmapped chunks where its
correctness matters more, since their lengths are always multiples of
the alignment.
上级 4e3df7be
...@@ -43,8 +43,8 @@ static struct { ...@@ -43,8 +43,8 @@ static struct {
#define DONTCARE 16 #define DONTCARE 16
#define RECLAIM 163840 #define RECLAIM 163840
#define CHUNK_SIZE(c) ((c)->csize & SIZE_MASK) #define CHUNK_SIZE(c) ((c)->csize & -2)
#define CHUNK_PSIZE(c) ((c)->psize & SIZE_MASK) #define CHUNK_PSIZE(c) ((c)->psize & -2)
#define PREV_CHUNK(c) ((struct chunk *)((char *)(c) - CHUNK_PSIZE(c))) #define PREV_CHUNK(c) ((struct chunk *)((char *)(c) - CHUNK_PSIZE(c)))
#define NEXT_CHUNK(c) ((struct chunk *)((char *)(c) + CHUNK_SIZE(c))) #define NEXT_CHUNK(c) ((struct chunk *)((char *)(c) + CHUNK_SIZE(c)))
#define MEM_TO_CHUNK(p) (struct chunk *)((char *)(p) - OVERHEAD) #define MEM_TO_CHUNK(p) (struct chunk *)((char *)(p) - OVERHEAD)
...@@ -52,8 +52,6 @@ static struct { ...@@ -52,8 +52,6 @@ static struct {
#define BIN_TO_CHUNK(i) (MEM_TO_CHUNK(&mal.bins[i].head)) #define BIN_TO_CHUNK(i) (MEM_TO_CHUNK(&mal.bins[i].head))
#define C_INUSE ((size_t)1) #define C_INUSE ((size_t)1)
#define C_FLAGS ((size_t)3)
#define C_SIZE SIZE_MASK
#define IS_MMAPPED(c) !((c)->csize & (C_INUSE)) #define IS_MMAPPED(c) !((c)->csize & (C_INUSE))
......
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