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=-11.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 F1BCAC433ED for ; Mon, 12 Apr 2021 13:13:51 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6D92C61288 for ; Mon, 12 Apr 2021 13:13:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D92C61288 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=I3lkxZDBhnFhmsbTV6dDLI2Ccaz67u3nBP+H+MGbImM=; b=qeQ+XGtoYqdThHxxnSj+aFYdM 3gaLaVsyv7N+ctBXTf1M3KdGtu9ed8IQm2FIYkhFjjP7lmeBn2xXUM/j/9m9WQ3aTzoVsk4Y/gMZI Tac+D21jyAvhiuHbl4vDUcuWekVZZpT3b2ctrPraLtNM98zca6XslY+gYT1aXQ2Lxc7XPN2A+A4hn 2g7mUHHdktTDzFEj/9GvaQ+0Y+es6ipv8dExL/VLNRUS+NeYWBO0HuA8niUbKBo1aT62duIFrut2e DTK23NpQkj7G3ojI2m8Cbj4JHG0kl1w06cHb+UdQfIshex0maX0D04F2ieB5NO8lZmn4eSgW28CE4 OE5bB2ezw==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lVwMU-006n6w-Ja; Mon, 12 Apr 2021 13:12:18 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lVwML-006n5w-PW for linux-arm-kernel@desiato.infradead.org; Mon, 12 Apr 2021 13:12:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Sender:Reply-To:Content-ID:Content-Description; bh=KEu8l+x8kdU6SE8gW05vx8Dm1nMAqA+qoUbk3y4APEA=; b=lGWrR2CW4Zy1G9MTz6ypyx/2WR J7cqfs+EMgRlSKMnqS6VYHI2aEnrTnNIUiZW0ISnCiCc9+QDLHa93WP8OabEXc4lpRYXspDAauSWY 73kOOCVAo6/+z9v8cXRDnSdmYaIREegvmXmBPmLc0zBAynml2ezrOQ3xZ5MipqdykpcoLFNT/w/uk UJIvDXBE/ClrAM+BXWYTYOXUevv6kOmWZI4ERWpb8bFfaZ5JzfnRcCWwVn1G3fkHL1+b9TPyc8tcU g5775CMj0zqiNuX4yXidMTsHcoxHyup6/HtrWuOWWG2Vx63StoUos5c416GuMuIFuCe7DwiIomaMk PQjza4eA==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lVwMG-006Fnd-1D for linux-arm-kernel@lists.infradead.org; Mon, 12 Apr 2021 13:12:08 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 49B446128A; Mon, 12 Apr 2021 13:12:01 +0000 (UTC) From: Catalin Marinas To: linux-crypto@vger.kernel.org, Ard Biesheuvel Cc: Will Deacon , Catalin Marinas , Sebastian Andrzej Siewior , Dave Martin , Peter Zijlstra , Eric Biggers , Ingo Molnar , Mark Brown , Herbert Xu , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Andy Lutomirski Subject: Re: (subset) [PATCH v2 0/9] running kernel mode SIMD with softirqs disabled Date: Mon, 12 Apr 2021 14:11:13 +0100 Message-Id: <161822613829.4133.7312323262518323547.b4-ty@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210302090118.30666-1-ardb@kernel.org> References: <20210302090118.30666-1-ardb@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210412_061204_118975_28CE91EC X-CRM114-Status: GOOD ( 13.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 2 Mar 2021 10:01:09 +0100, Ard Biesheuvel wrote: > [ TL;DR for the non-ARM folks on CC: disabling softirq processing when using > SIMD in kernel mode could reduce complexity and improve performance, but we > need to decide whether we can do this, and how much softirq processing > latency we can tolerate. If we can find a satisfactory solution for this, > we might do the same for x86 and 32-bit ARM as well. > > However, based on preliminary off-list discussions with peterz and luto, it > seems that for x86, there is a preference for using per-CPU buffers to > preserve/restore the task context's kernel mode SIMD state when the task is > interrupted to perform kernel mode SIMD in softirq context. On arm64, we > actually had this arrangement before, and removed it because it made > reasoning about preserving/restoring userland SVE state (32 SIMD registers > of up to 2 kbit in size) rather complex. ] > > [...] Applied to arm64 (for-next/neon-softirqs-disabled), thanks! [1/9] arm64: assembler: remove conditional NEON yield macros https://git.kernel.org/arm64/c/27248fe1abb2 [2/9] arm64: assembler: introduce wxN aliases for wN registers https://git.kernel.org/arm64/c/4c4dcd3541f8 [3/9] arm64: fpsimd: run kernel mode NEON with softirqs disabled https://git.kernel.org/arm64/c/13150149aa6d -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel