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| author | David Goldblatt <davidgoldblatt@fb.com> | 2017-09-29 13:54:08 -0700 |
|---|---|---|
| committer | David Goldblatt <davidtgoldblatt@gmail.com> | 2017-10-02 14:54:46 -0700 |
| commit | 7a8bc7172b17e219b3603e99c8da44efb283e652 (patch) | |
| tree | 3dbabc473cfe77fccb75cd69679a09974d1f747d /include | |
| parent | 0720192a323f5dd2dd27828c6ab3061f8f039416 (diff) | |
| download | platform_external_jemalloc_new-7a8bc7172b17e219b3603e99c8da44efb283e652.tar.gz platform_external_jemalloc_new-7a8bc7172b17e219b3603e99c8da44efb283e652.tar.bz2 platform_external_jemalloc_new-7a8bc7172b17e219b3603e99c8da44efb283e652.zip | |
ARM: Don't extend bit LG_VADDR to compute high address bits.
In userspace ARM on Linux, zero-ing the high bits is the correct way to do this.
This doesn't fix the fact that we currently set LG_VADDR to 48 on ARM, when in
fact larger virtual address sizes are coming soon. We'll cross that bridge when
we come to it.
Diffstat (limited to 'include')
| -rw-r--r-- | include/jemalloc/internal/rtree.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/jemalloc/internal/rtree.h b/include/jemalloc/internal/rtree.h index b5d4db39..4563db23 100644 --- a/include/jemalloc/internal/rtree.h +++ b/include/jemalloc/internal/rtree.h @@ -178,9 +178,21 @@ rtree_leaf_elm_bits_read(tsdn_t *tsdn, rtree_t *rtree, rtree_leaf_elm_t *elm, JEMALLOC_ALWAYS_INLINE extent_t * rtree_leaf_elm_bits_extent_get(uintptr_t bits) { +# ifdef __aarch64__ + /* + * aarch64 doesn't sign extend the highest virtual address bit to set + * the higher ones. Instead, the high bits gets zeroed. + */ + uintptr_t high_bit_mask = ((uintptr_t)1 << LG_VADDR) - 1; + /* Mask off the slab bit. */ + uintptr_t low_bit_mask = ~(uintptr_t)1; + uintptr_t mask = high_bit_mask & low_bit_mask; + return (extent_t *)(bits & mask); +# else /* Restore sign-extended high bits, mask slab bit. */ return (extent_t *)((uintptr_t)((intptr_t)(bits << RTREE_NHIB) >> RTREE_NHIB) & ~((uintptr_t)0x1)); +# endif } JEMALLOC_ALWAYS_INLINE szind_t |