From: Daniel Vetter <daniel@ffwll.ch>
To: Corentin Labbe <clabbe.montjoie@gmail.com>
Cc: Ben Skeggs <bskeggs@redhat.com>, Dave Airlie <airlied@linux.ie>,
Christoph Hellwig <hch@lst.de>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
dri-devel <dri-devel@lists.freedesktop.org>,
Nouveau Dev <nouveau@lists.freedesktop.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"list@263.net:IOMMU DRIVERS <iommu@lists.linux-foundation.org>,
Joerg Roedel <joro@8bytes.org>,"
<iommu@lists.linux-foundation.org>
Subject: Re: DMA-API: cacheline tracking ENOMEM, dma-debug disabled due to nouveau ?
Date: Fri, 16 Aug 2019 20:45:11 +0200 [thread overview]
Message-ID: <CAKMK7uGb0twmXUXS5GVN0mmGW-csWH524psJFfdFYuou9YXFDw@mail.gmail.com> (raw)
In-Reply-To: <20190816143146.GB30445@Red>
On Fri, Aug 16, 2019 at 4:31 PM Corentin Labbe
<clabbe.montjoie@gmail.com> wrote:
> 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.
>
> Note that it never go down and when I terminate my X session, it stays the same.
> So without any "real" GPU work, does it is still normal to have so many active mapping ?
Might just be the dma_alloc cache. It should go down under memory
pressure I think. Otherwise might also be a leak.
> For example, when doing some transfer, the ahci mapping number changes and then always go down to 6.
gpu drivers tend to cache everything, all the time ...
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
prev parent reply other threads:[~2019-08-16 18:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-14 14:50 DMA-API: cacheline tracking ENOMEM, dma-debug disabled due to nouveau ? Corentin Labbe
2019-08-14 17:49 ` Daniel Vetter
2019-08-15 13:35 ` Christoph Hellwig
2019-08-15 13:50 ` Robin Murphy
2019-08-16 14:31 ` Corentin Labbe
2019-08-16 18:45 ` Daniel Vetter [this message]
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