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author | alc <alc@FreeBSD.org> | 2016-07-07 20:58:16 +0000 |
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committer | alc <alc@FreeBSD.org> | 2016-07-07 20:58:16 +0000 |
commit | 694dd903a34021d3c78796fe5292cc4e0cd04650 (patch) | |
tree | 24e0c97c72a21e1ff9def632a962fa8ac904345f /lib/libc | |
parent | 7c112ea9871eb80bd5a745a831a3a17fd193ab2e (diff) | |
download | FreeBSD-src-694dd903a34021d3c78796fe5292cc4e0cd04650.zip FreeBSD-src-694dd903a34021d3c78796fe5292cc4e0cd04650.tar.gz |
Change the type of the map entry's next_read field from a vm_pindex_t to a
vm_offset_t. (This field is used to detect sequential access to the virtual
address range represented by the map entry.) There are three reasons to
make this change. First, a vm_offset_t is smaller on 32-bit architectures.
Consequently, a struct vm_map_entry is now smaller on 32-bit architectures.
Second, a vm_offset_t can be written atomically, whereas it may not be
possible to write a vm_pindex_t atomically on a 32-bit architecture. Third,
using a vm_pindex_t makes the next_read field dependent on which object in
the shadow chain is being read from.
Replace an "XXX" comment.
Reviewed by: kib
Approved by: re (gjb)
Sponsored by: EMC / Isilon Storage Division
Diffstat (limited to 'lib/libc')
0 files changed, 0 insertions, 0 deletions