[PATCH] arm64: mte: optimize asynchronous tag check fault flag check

[Catalin Marinas]

On Tue, 17 Nov 2020 19:20:51 -0800, Peter Collingbourne wrote:
> We don't need to check for MTE support before checking the flag
> because it can only be set if the hardware supports MTE. As a result
> we can unconditionally check the flag bit which is expected to be in
> a register and therefore the check can be done in a single instruction
> instead of first needing to load the hwcaps.
> 
> On a DragonBoard 845c with a kernel built with CONFIG_ARM64_MTE=y with
> the powersave governor this reduces the cost of a kernel entry/exit
> (invalid syscall) from 465.1ns to 463.8ns.

Applied to arm64 (for-next/misc), thanks!

[1/1] arm64: mte: optimize asynchronous tag check fault flag check
      https://git.kernel.org/arm64/c/739003c64283

-- 
Catalin