x86: Reorder mm_context_t to remove x86_64 alignment padding and thus shrink mm_struct

Reorder mm_context_t to remove alignment padding on 64 bit
builds shrinking its size from 64 to 56 bytes.

This allows mm_struct to shrink from 840 to 832 bytes, so using
one fewer cache lines, and getting more objects per slab when
using slub.

slabinfo mm_struct reports
before :-

    Sizes (bytes)     Slabs
    -----------------------------------
    Object :     840  Total  :       7
    SlabObj:     896  Full   :       1
    SlabSiz:   16384  Partial:       4
    Loss   :      56  CpuSlab:       2
    Align  :      64  Objects:      18

after :-

    Sizes (bytes)     Slabs
    ----------------------------------
    Object :     832  Total  :       7
    SlabObj:     832  Full   :       1
    SlabSiz:   16384  Partial:       4
    Loss   :       0  CpuSlab:       2
    Align  :      64  Objects:      19

Signed-off-by: Richard Kennedy <[email protected]>
Cc: [email protected]
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Pekka Enberg <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions