Base max_fast on alignment, not width, of bins (Bug 24903)

set_max_fast sets the "impossibly small" value based on,
eventually, MALLOC_ALIGNMENT.  The comparisons for the smallest
chunk used is, eventually, MIN_CHUNK_SIZE.  Note that i386
is the only platform where these are the same, so a smallest
chunk *would* be put in a no-fastbins fastbin.

This change calculates the "impossibly small" value
based on MIN_CHUNK_SIZE instead, so that we can know it will
always be impossibly small.

(cherry picked from commit ff12e0fb91)
This commit is contained in:
DJ Delorie 2019-10-30 18:03:14 -04:00 committed by Arjun Shankar
parent 1b96d1d90b
commit a683450f26

View File

@ -1635,7 +1635,7 @@ static INTERNAL_SIZE_T global_max_fast;
#define set_max_fast(s) \
global_max_fast = (((s) == 0) \
? SMALLBIN_WIDTH : ((s + SIZE_SZ) & ~MALLOC_ALIGN_MASK))
? MIN_CHUNK_SIZE / 2 : ((s + SIZE_SZ) & ~MALLOC_ALIGN_MASK))
static inline INTERNAL_SIZE_T
get_max_fast (void)