romenskiy2012/jemalloc
1
0
Fork 0
mirror of https://github.com/jemalloc/jemalloc.git synced 2026-08-26 00:53:34 +03:00
Code Issues Projects Releases Packages Wiki Activity

Use tsd offset_state instead of atomic

Browse source 
While working on #852, I noticed the prng state is atomic.  This is the only
atomic use of prng in all of jemalloc.  Instead, use a threadlocal prng
state if possible to avoid unnecessary cache line contention.
This commit is contained in:
Dave Watson 2017-10-13 10:27:13 -07:00
parent cb3b72b975
commit d6feed6e66
3 changed files with 22 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

13
include/jemalloc/internal/extent_inlines.h
View file

@ -196,9 +196,16 @@ extent_addr_randomize(tsdn_t *tsdn, extent_t *extent, size_t alignment) {
if (alignment < PAGE) {
unsigned lg_range = LG_PAGE -
lg_floor(CACHELINE_CEILING(alignment));
size_t r =
prng_lg_range_zu(&extent_arena_get(extent)->offset_state,
lg_range, true);
size_t r;
if (!tsdn_null(tsdn)) {
tsd_t *tsd = tsdn_tsd(tsdn);
r = (size_t)prng_lg_range_u64(
tsd_offset_statep_get(tsd), lg_range);
} else {
r = prng_lg_range_zu(
&extent_arena_get(extent)->offset_state,
lg_range, true);
}
uintptr_t random_offset = ((uintptr_t)r) << (LG_PAGE -
lg_range);
extent->e_addr = (void *)((uintptr_t)extent->e_addr +