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David Sterba authored
Currently there's a 4B hole in the structure between refs and state and there are only 16 bits used so we can make it unsigned. This will get a better packing and may save some stack space for local variables. The size of extent_state gets reduced by 8B and there are usually a lot of slab objects. struct extent_state { u64 start; /* 0 8 */ u64 end; /* 8 8 */ struct rb_node rb_node; /* 16 24 */ wait_queue_head_t wq; /* 40 24 */ /* --- cacheline 1 boundary (64 bytes) --- */ atomic_t refs; /* 64 4 */ /* XXX 4 bytes hole, try to pack */ long unsigned int state; /* 72 8 */ u64 private; /* 80 8 */ /* size: 88, cachelines: 2, members: 7 */ /* sum members: 84, holes: 1, sum holes: 4 */ /* last cacheline: 24 bytes */ }; Signed-off-by:
David Sterba <dsterba@suse.cz> Signed-off-by:
Chris Mason <clm@fb.com>
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