From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753183AbcHVKAn (ORCPT ); Mon, 22 Aug 2016 06:00:43 -0400 Received: from foss.arm.com ([217.140.101.70]:50363 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752247AbcHVKAl (ORCPT ); Mon, 22 Aug 2016 06:00:41 -0400 Date: Mon, 22 Aug 2016 11:00:07 +0100 From: Will Deacon To: Suzuki K Poulose Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, andre.przywara@arm.com, James Morse , Geoff Levand Subject: Re: [PATCH 6/8] arm64: Introduce raw_{d,i}cache_line_size Message-ID: <20160822100007.GB14680@arm.com> References: <1471525832-21209-1-git-send-email-suzuki.poulose@arm.com> <1471525832-21209-7-git-send-email-suzuki.poulose@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1471525832-21209-7-git-send-email-suzuki.poulose@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 18, 2016 at 02:10:30PM +0100, Suzuki K Poulose wrote: > On systems with mismatched i/d cache min line sizes, we need to use > the smallest size possible across all CPUs. This will be done by fetching > the system wide safe value from CPU feature infrastructure. > However the some special users(e.g kexec, hibernate) would need the line > size on the CPU (rather than the system wide), when the system wide > feature may not be accessible. Provide another helper which will fetch > cache line size on the current CPU. Why are these users "special"? Using a smaller line size shouldn't affect correctness, and I don't see kexec and hibernate as being performance critical in their cache maintenance. Will