From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8669BC433E9 for ; Wed, 27 Jan 2021 17:19:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 400AF64DA0 for ; Wed, 27 Jan 2021 17:19:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232324AbhA0RT2 (ORCPT ); Wed, 27 Jan 2021 12:19:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:40194 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235671AbhA0RR3 (ORCPT ); Wed, 27 Jan 2021 12:17:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3543864D99; Wed, 27 Jan 2021 17:16:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611767772; bh=QEn3AwN++ibSZJbYsfjHXLopDcjytE0gWYxS4s3GF0Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=rxjRVJoX2E1b3ub3NeXROX65hjFV/n3ruiDX3Jg2rFspZSMEQYHzkQ+DhSocI9MFy V8Lz947ClecGI7JzSVvBD/apXNXAhwDvaLSvB2bcZCdqBFnXa8fT/mkjSts7uCMtyB gqZfF4y8iSF+TZHdXCMMdKG3qBmTEQVqKIY6e9eIGl3/X6fQSg0G6uWAC1c0GNEoWB aubrx1wrsptYu8LS0SrOkAvUpdzrOjM3QNohwquR8iCEJ9osuK8FLOSD39IJ7igtle BDYb9/BUm/2uZaTUzqkUE/xOApbDCFLdUpxLTFQhwy4h7JWwNFCXuWfFv6+guQPdNX CDEkII+uEdF1w== Date: Wed, 27 Jan 2021 17:16:06 +0000 From: Will Deacon To: Hugh Dickins Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Linus Torvalds , Vinayak Menon , Nick Desaulniers , kernel-team@android.com Subject: Re: [PATCH v4 0/8] Create 'old' ptes for faultaround mappings on arm64 with hardware access flag Message-ID: <20210127171605.GD358@willie-the-truck> References: <20210120173612.20913-1-will@kernel.org> <20210126230851.GE30941@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 26, 2021 at 03:28:22PM -0800, Hugh Dickins wrote: > On Tue, 26 Jan 2021, Will Deacon wrote: > > On Wed, Jan 20, 2021 at 05:36:04PM +0000, Will Deacon wrote: > > > Hi all, > > > > > > This is version four of the patches I previously posted here: > > > > > > v1: https://lore.kernel.org/r/20201209163950.8494-1-will@kernel.org > > > v2: https://lore.kernel.org/r/20210108171517.5290-1-will@kernel.org > > > v3: https://lore.kernel.org/r/20210114175934.13070-1-will@kernel.org > > > > > > The patches allow architectures to opt-in at runtime for faultaround > > > mappings to be created as 'old' instead of 'young'. Although there have > > > been previous attempts at this, they failed either because the decision > > > was deferred to userspace [1] or because it was done unconditionally and > > > shown to regress benchmarks for particular architectures [2]. > > > > > > The big change since v3 is that the immutable fields of 'struct vm_fault' > > > now live in a 'const' anonymous struct. Although Clang will silently > > > accept modifications to these fields [3], GCC emits an error. The > > > resulting diffstat is _considerably_ more manageable with this approach. > > > > The only changes I have pending against this series are cosmetic (commit > > logs). Can I go ahead and queue this in the arm64 tree so that it can sit > > in linux-next for a bit? (positive or negative feedback appreciated!). > > That would be fine by me: I ran v3 on rc3, then the nicer smaller v4 > on rc4, and saw no problems when running either of them (x86_64 only). Thanks, Hugh. I'll stick these into -next later today and we'll see how we get on. Will