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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 4601FC35671 for ; Mon, 24 Feb 2020 12:03:28 +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 197E220828 for ; Mon, 24 Feb 2020 12:03:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="RD7X++rh"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="g1I9RIlP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 197E220828 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk 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=n/g1lAbbwzVK44VOcxVYzDHFfbvv4yax+Z9DzbSJT2s=; b=RD7X++rhp4u2Kg qSUhPZQsV4IGbsal5shF1Q0usXa4WiHcEwxfkZyud19uSNQUo/qMVJzRcsL90eLQR5yi6VC0NeVyj mlxYJX6MJ2Mm9Qi8fxHV7qTndLV9vpDO4NGcqzzgDALA8+mphbNgrgcUW8M77V4t2CDEBO9mIPjwx S/40PW1lQQ5lZmEnrKbtRxLv/YFtg9kyNXHmXq9baEL/49ZbYMmNvmlS04zw7SwjF3Bn6uZ6rT36W G4d6d1NGkEutoiy7vYcvFK5BL84kzYw/uvuRe6+V/fTWlM3r9UBnQPv0GnrY0BlJICbKm+Adwo1o5 Af06Y/EdBdm3zH1/YePA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6CSG-0000qR-DR; Mon, 24 Feb 2020 12:03:20 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:3201:214:fdff:fe10:1be6]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j6CSA-0000pj-T2 for linux-arm-kernel@lists.infradead.org; Mon, 24 Feb 2020 12:03:18 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=t5KPllfCzU4AasIlRCx7IzfWUIVfM/xDWS4+N7wn5YA=; b=g1I9RIlPEPLzZWdOSbIZxCjpj LpMV7CqOwjfFjrIcnMazJf2/Mmg90x8pv9//qmp8jQeSXfZjcEgb41hEb0Cpa+JHdndB/RDrHMXEl kWz02pgsYVHwIV4OEGIvsFv7Zm5QioaBlb2MUhpFH7eu7fQoVzymGUxZZ0fMCIkyqDk1cT36KuBGE iO73eFzbLIc6kluM0d8NpnNsm0iSbUFe1j3WLJFgVwOe69LzYFiPwTvkfQdqP98jFOyoqtFohXZQJ NGcvXqREeIXSER4KikTrW7pnujpKNi56cCH2F1FGoJqfsDl2o/y/N349pCffazDf2+vgVaH715U5T EkbTycHjg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:56262) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1j6CS5-0002Xr-Ky; Mon, 24 Feb 2020 12:03:09 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1j6CRz-0006P7-9v; Mon, 24 Feb 2020 12:03:03 +0000 Date: Mon, 24 Feb 2020 12:03:03 +0000 From: Russell King - ARM Linux admin To: yifeng wu Subject: Re: Subject: [PATCH] arm/kernel/head.S: optimize __create_page_tables function Message-ID: <20200224120303.GQ25745@shell.armlinux.org.uk> References: <20200224110508.GP25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200224_040316_958689_03B324EE X-CRM114-Status: UNSURE ( 8.74 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, 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 Hi, On Mon, Feb 24, 2020 at 07:54:07PM +0800, yifeng wu wrote: > Thank you very much for your reply. > I have tested on my machine. It takes about 0.5 seconds to copy the memory > (16M size) with "str" instruction, and only 0.1 seconds with "stmia" ITYM 16k. You say "copy" but we're setting memory to zero. I'm quite surprised by that difference, which CPU was this measured on? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel