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=-2.5 required=3.0 tests=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 B94FDC433E0 for ; Sat, 27 Jun 2020 07:02:46 +0000 (UTC) Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (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 6DCB220857 for ; Sat, 27 Jun 2020 07:02:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DCB220857 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id 14FE1204CA; Sat, 27 Jun 2020 07:02:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id fJ9M+s446e6d; Sat, 27 Jun 2020 07:02:43 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by silver.osuosl.org (Postfix) with ESMTP id D52A9204A7; Sat, 27 Jun 2020 07:02:42 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id B52DEC0863; Sat, 27 Jun 2020 07:02:42 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id E1334C016F for ; Sat, 27 Jun 2020 07:02:41 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id CE4C985582 for ; Sat, 27 Jun 2020 07:02:41 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id uNvHdGI8k5Zf for ; Sat, 27 Jun 2020 07:02:40 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by fraxinus.osuosl.org (Postfix) with ESMTPS id 874A385549 for ; Sat, 27 Jun 2020 07:02:40 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 9E9AF68B02; Sat, 27 Jun 2020 09:02:36 +0200 (CEST) Date: Sat, 27 Jun 2020 09:02:36 +0200 From: Christoph Hellwig To: Jonathan Lemon Subject: Re: the XSK buffer pool needs be to reverted Message-ID: <20200627070236.GA11854@lst.de> References: <20200626074725.GA21790@lst.de> <20200626205412.xfe4lywdbmh3kmri@bsd-mbp> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200626205412.xfe4lywdbmh3kmri@bsd-mbp> User-Agent: Mutt/1.5.17 (2007-11-01) Cc: netdev@vger.kernel.org, iommu@lists.linux-foundation.org, =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , Christoph Hellwig X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" On Fri, Jun 26, 2020 at 01:54:12PM -0700, Jonathan Lemon wrote: > On Fri, Jun 26, 2020 at 09:47:25AM +0200, Christoph Hellwig wrote: > > > > Note that this is somewhat urgent, as various of the APIs that the code > > is abusing are slated to go away for Linux 5.9, so this addition comes > > at a really bad time. > > Could you elaborate on what is upcoming here? Moving all these calls out of line, and adding a bypass flag to avoid the indirect function call for IOMMUs in direct mapped mode. > Also, on a semi-related note, are there limitations on how many pages > can be left mapped by the iommu? Some of the page pool work involves > leaving the pages mapped instead of constantly mapping/unmapping them. There are, but I think for all modern IOMMUs they are so big that they don't matter. Maintaines of the individual IOMMU drivers might know more. > On a heavily loaded box with iommu enabled, it seems that quite often > there is contention on the iova_lock. Are there known issues in this > area? I'll have to defer to the IOMMU maintainers, and for that you'll need to say what code you are using. Current mainlaine doesn't even have an iova_lock anywhere. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu