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=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 6D73CC3A589 for ; Thu, 15 Aug 2019 13:36:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A58C2084D for ; Thu, 15 Aug 2019 13:36:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732330AbfHONf7 (ORCPT ); Thu, 15 Aug 2019 09:35:59 -0400 Received: from verein.lst.de ([213.95.11.211]:46778 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731194AbfHONf6 (ORCPT ); Thu, 15 Aug 2019 09:35:58 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id A750A68AFE; Thu, 15 Aug 2019 15:35:54 +0200 (CEST) Date: Thu, 15 Aug 2019 15:35:54 +0200 From: Christoph Hellwig To: Corentin Labbe , bskeggs@redhat.com, airlied@linux.ie, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org Subject: Re: DMA-API: cacheline tracking ENOMEM, dma-debug disabled due to nouveau ? Message-ID: <20190815133554.GE12036@lst.de> References: <20190814145033.GA11190@Red> <20190814174927.GT7444@phenom.ffwll.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190814174927.GT7444@phenom.ffwll.local> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 14, 2019 at 07:49:27PM +0200, Daniel Vetter wrote: > On Wed, Aug 14, 2019 at 04:50:33PM +0200, Corentin Labbe wrote: > > Hello > > > > Since lot of release (at least since 4.19), I hit the following error message: > > DMA-API: cacheline tracking ENOMEM, dma-debug disabled > > > > After hitting that, I try to check who is creating so many DMA mapping and see: > > cat /sys/kernel/debug/dma-api/dump | cut -d' ' -f2 | sort | uniq -c > > 6 ahci > > 257 e1000e > > 6 ehci-pci > > 5891 nouveau > > 24 uhci_hcd > > > > Does nouveau having this high number of DMA mapping is normal ? > > Yeah seems perfectly fine for a gpu. That is a lot and apparently overwhelm the dma-debug tracking. Robin rewrote this code in Linux 4.21 to work a little better, so I'm curious why this might have changes in 4.19, as dma-debug did not change at all there.