From: Robin Murphy <robin.murphy@arm.com>
To: Christoph Hellwig <hch@lst.de>,
Corentin Labbe <clabbe.montjoie@gmail.com>,
bskeggs@redhat.com, airlied@linux.ie, m.szyprowski@samsung.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 14:50:52 +0100 [thread overview]
Message-ID: <cdb43f4b-55ff-80c3-8d27-56238b2ab1a1@arm.com> (raw)
In-Reply-To: <20190815133554.GE12036@lst.de>
On 15/08/2019 14:35, Christoph Hellwig 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.
>
> 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.
FWIW, the cacheline tracking entries are a separate thing from the
dma-debug entries that I rejigged - judging by those numbers there
should still be plenty of free dma-debug entries, but for some reason it
has failed to extend the radix tree :/
Robin.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2019-08-15 13:51 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 [this message]
2019-08-16 14:31 ` Corentin Labbe
2019-08-16 18:45 ` Daniel Vetter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cdb43f4b-55ff-80c3-8d27-56238b2ab1a1@arm.com \
--to=robin.murphy@arm.com \
--cc=airlied@linux.ie \
--cc=bskeggs@redhat.com \
--cc=clabbe.montjoie@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=hch@lst.de \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=nouveau@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).