Re: [PATCH] arm64: mte: switch GCR_EL1 on task switch rather than entry/exit
From: Catalin Marinas <catalin.marinas@arm.com>
Date: 2021-07-02 17:46:32
On Thu, Jul 01, 2021 at 08:19:22PM -0700, Peter Collingbourne wrote:
Accessing GCR_EL1 and issuing an ISB can be expensive on some microarchitectures. To avoid taking this performance hit on every kernel entry/exit, switch GCR_EL1 on task switch rather than entry/exit.
Is it the ISB that's causing issues or the MRS/MSR as well? I think we can avoid the ISB when PtrAuth is enabled by shuffling the entry code a bit. We can also simplify the mte_set_gcr macro to avoid an MRS. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel