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=-5.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT 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 D2559C10F0E for ; Fri, 12 Apr 2019 09:53:01 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 8E34A20850 for ; Fri, 12 Apr 2019 09:53:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="mOhTlX+l" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8E34A20850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5bSXGhG72ieEhUKurqBi6+n+Q0q3G7L/S97yK1WhFKg=; b=mOhTlX+l5L2zGr m7+9pJVYE+/77cJNYInr+e55O+xBm2AE2OzzQT51LQtruJZ5XN2FsQlbsgIwPYGaaVg5n7w16c22i eDq9pz9GLzZtBckhZ/1SCowVyoK6zw/9YbuNRn06/HtjqMi8+F/dcLX8eG83uV2W822NxUNjUIoaQ TWxNxEBVQAxdizN46RD+n7xiLVwAnYDKaL5BUvixno9r7n13t7iJg3hxEJrovZhBRiehzzsmkR6Le 6+vFMAsEBENCnoIaPDm4kxK0Movr475yGTwycsKyCdjVrW9JKn1E9kmDll4h1qHIa6MfDLmwXMc75 n53cO7v5wjdc6f2nvurQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEsrh-0002Iz-L5; Fri, 12 Apr 2019 09:52:57 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hEsra-0002Fw-EI for linux-arm-kernel@lists.infradead.org; Fri, 12 Apr 2019 09:52:55 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D7EF415AB; Fri, 12 Apr 2019 02:52:49 -0700 (PDT) Received: from fuggles.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5B9553F59C; Fri, 12 Apr 2019 02:52:48 -0700 (PDT) Date: Fri, 12 Apr 2019 10:52:43 +0100 From: Will Deacon To: Zhangshaokun Subject: Re: [PATCH] arm64: do_csum: implement accelerated scalar version Message-ID: <20190412095243.GA27193@fuggles.cambridge.arm.com> References: <20190218230842.11448-1-ard.biesheuvel@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.1+86 (6f28e57d73f2) () X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190412_025250_593793_81271EA9 X-CRM114-Status: GOOD ( 16.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ard Biesheuvel , steve.capper@arm.com, netdev@vger.kernel.org, ilias.apalodimas@linaro.org, "huanglingyan \(A\)" , robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 12, 2019 at 10:31:16AM +0800, Zhangshaokun wrote: > On 2019/2/19 7:08, Ard Biesheuvel wrote: > > It turns out that the IP checksumming code is still exercised often, > > even though one might expect that modern NICs with checksum offload > > have no use for it. However, as Lingyan points out, there are > > combinations of features where the network stack may still fall back > > to software checksumming, and so it makes sense to provide an > > optimized implementation in software as well. > > > > So provide an implementation of do_csum() in scalar assembler, which, > > unlike C, gives direct access to the carry flag, making the code run > > substantially faster. The routine uses overlapping 64 byte loads for > > all input size > 64 bytes, in order to reduce the number of branches > > and improve performance on cores with deep pipelines. > > > > On Cortex-A57, this implementation is on par with Lingyan's NEON > > implementation, and roughly 7x as fast as the generic C code. > > > > Cc: "huanglingyan (A)" > > Signed-off-by: Ard Biesheuvel > > --- > > Test code after the patch. > > Hi maintainers and Ard, > > Any update on it? I'm waiting for Robin to come back with numbers for a C implementation. Robin -- did you get anywhere with that? Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel