From: Christoph Hellwig <hch@lst.de>
To: Corentin Labbe <clabbe.montjoie@gmail.com>,
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 ?
Date: Thu, 15 Aug 2019 15:35:54 +0200 [thread overview]
Message-ID: <20190815133554.GE12036@lst.de> (raw)
In-Reply-To: <20190814174927.GT7444@phenom.ffwll.local>
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.
next prev parent reply other threads:[~2019-08-15 13:36 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 [this message]
2019-08-15 13:50 ` Robin Murphy
2019-08-16 14:31 ` Corentin Labbe
2019-08-16 18:45 ` Daniel Vetter
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