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| author | Dave Watson <davejwatson@fb.com> | 2017-10-13 10:27:13 -0700 |
|---|---|---|
| committer | Dave Watson <davejwatson@fb.com> | 2017-11-14 08:58:18 -0800 |
| commit | d6feed6e6631d00806607cfe16a796e337752044 (patch) | |
| tree | 4186aaf4ba5c325312f3faaa709a955b15be253c /include | |
| parent | cb3b72b9756d124565ed12e005065ad6f0769568 (diff) | |
| download | platform_external_jemalloc_new-d6feed6e6631d00806607cfe16a796e337752044.tar.gz platform_external_jemalloc_new-d6feed6e6631d00806607cfe16a796e337752044.tar.bz2 platform_external_jemalloc_new-d6feed6e6631d00806607cfe16a796e337752044.zip | |
Use tsd offset_state instead of atomic
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.
Diffstat (limited to 'include')
| -rw-r--r-- | include/jemalloc/internal/extent_inlines.h | 13 | ||||
| -rw-r--r-- | include/jemalloc/internal/tsd.h | 2 |
2 files changed, 12 insertions, 3 deletions
diff --git a/include/jemalloc/internal/extent_inlines.h b/include/jemalloc/internal/extent_inlines.h index 610072eb..9f5c5cd2 100644 --- a/include/jemalloc/internal/extent_inlines.h +++ b/include/jemalloc/internal/extent_inlines.h @@ -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 + diff --git a/include/jemalloc/internal/tsd.h b/include/jemalloc/internal/tsd.h index 155a2ec6..0b9841aa 100644 --- a/include/jemalloc/internal/tsd.h +++ b/include/jemalloc/internal/tsd.h @@ -65,6 +65,7 @@ typedef void (*test_callback_t)(int *); O(arenas_tdata_bypass, bool, bool) \ O(reentrancy_level, int8_t, int8_t) \ O(narenas_tdata, uint32_t, uint32_t) \ + O(offset_state, uint64_t, uint64_t) \ O(thread_allocated, uint64_t, uint64_t) \ O(thread_deallocated, uint64_t, uint64_t) \ O(prof_tdata, prof_tdata_t *, prof_tdata_t *) \ @@ -84,6 +85,7 @@ typedef void (*test_callback_t)(int *); 0, \ 0, \ 0, \ + 0, \ NULL, \ RTREE_CTX_ZERO_INITIALIZER, \ NULL, \ |