[RFC] arm64:change jump_label to use branch instruction, not use NOP instr

[Peter Zijlstra]

On Fri, Jul 31, 2015 at 03:41:37PM +0800, yalin wang wrote:
> This change a little arch_static_branch(), use b . + 4 for false
> return, why? According to aarch64 TRM, if both source and dest
> instr are branch instr, can patch the instr directly, don't need
> all cpu to do ISB for sync, this means we can call
> aarch64_insn_patch_text_nosync() during patch_text(),
> will improve the performance when change a static_key.

This doesn't parse.. What?

Also, this conflicts with the jump label patches I've got.