Patch to 3.0.86 (gregkh)
fs: jbd2: backport from aosp-common-3.4-kernel (johnnyslt)
defconfig: enable cgroup timer slack
ARM: 7173/1: Add optimised swahb32() byteswap helper for v6 and above
ARMv6 and later processors have the REV16 instruction, which swaps
the bytes within each halfword of a register value.

This is already used to implement swab16(), but since the native
operation performaed by REV16 is actually swahb32(), this patch
renames the existing swab16() helper accordingly and defines
__arch_swab16() in terms of it.  This allows calls to both swab16()
and swahb32() to be optimised.

The compilers generated code might improve someday, but as of
4.5.2 the code generated for pure C implementing these 16-bit
bytesswaps remains pessimal.

swahb32() is useful for converting 32-bit Thumb instructions
between integer and memory representation on BE8 platforms (among
other uses).

(johnnyslt)