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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 E92E9C433E0 for ; Thu, 28 May 2020 07:33:53 +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 BFC922088E for ; Thu, 28 May 2020 07:33:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="B2FAHzz/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BFC922088E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=8bytes.org 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=zKWUQZKH30mODZAqQztY36zmtZGQjPlFo9h3Sxnzq3w=; b=B2FAHzz/lS6LOP 7R9EfBfafcAWlfep3c50FC6vBdXSc/owFBTHh1Asnm5m1Z4jTPl2lz8jgk9k/isQPlAWWNUvpQkNp yciBa5nY8ttfZjrKRdIH4Lpo6cEt0DrmXDj5TrkSteERJgNAF+qdFMXO9wmBaMXcFZVKxx1M3Xch0 WEyK3DSBX25Fs+3au8v1KkzNRlGiGmoDEO+8/mWT+iRPf70mYqJB+jZJNTYutPgYaFcGFMQed5yzk YA+Gora/zKP7AuKw9s+X2sh/b+GVEn3UHqIvMiIYl4AnPllFk3IvX3Txv4nTZAoskdQk898koc6M/ x6v65yQEBCVWdCrqa7ew==; 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 1jeD32-0008Ie-Ry; Thu, 28 May 2020 07:33:52 +0000 Received: from 8bytes.org ([81.169.241.247] helo=theia.8bytes.org) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jeD2z-0008Ht-2D for linux-arm-kernel@lists.infradead.org; Thu, 28 May 2020 07:33:51 +0000 Received: by theia.8bytes.org (Postfix, from userid 1000) id B776F327; Thu, 28 May 2020 09:33:45 +0200 (CEST) Date: Thu, 28 May 2020 09:33:44 +0200 From: Joerg Roedel To: Bjorn Helgaas Subject: Re: [PATCH 0/2] Introduce PCI_FIXUP_IOMMU Message-ID: <20200528073344.GO5221@8bytes.org> References: <1590493749-13823-1-git-send-email-zhangfei.gao@linaro.org> <20200527181842.GA256680@bjorn-Precision-5520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200527181842.GA256680@bjorn-Precision-5520> 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-20200528_003349_254105_1F8265A1 X-CRM114-Status: GOOD ( 10.67 ) 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: jean-philippe , Lorenzo Pieralisi , Herbert Xu , Arnd Bergmann , linux-pci@vger.kernel.org, Greg Kroah-Hartman , Hanjun Guo , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, kenneth-lee-2012@foxmail.com, linux-acpi@vger.kernel.org, Wangzhou , linux-crypto@vger.kernel.org, Sudeep Holla , Bjorn Helgaas , Zhangfei Gao , linux-arm-kernel@lists.infradead.org, Len Brown 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 Wed, May 27, 2020 at 01:18:42PM -0500, Bjorn Helgaas wrote: > Is this slowdown significant? We already iterate over every device > when applying PCI_FIXUP_FINAL quirks, so if we used the existing > PCI_FIXUP_FINAL, we wouldn't be adding a new loop. We would only be > adding two more iterations to the loop in pci_do_fixups() that tries > to match quirks against the current device. I doubt that would be a > measurable slowdown. I don't know how significant it is, but I remember people complaining about adding new PCI quirks because it takes too long for them to run them all. That was in the discussion about the quirk disabling ATS on AMD Stoney systems. So it probably depends on how many PCI devices are in the system whether it causes any measureable slowdown. Regards, Joerg _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel