Nouveau - Dec 2017 - nouveau. swiotlb: coherent allocation failed for device 0000:01:00.0 size=2097152

Am 19.12.2017 um 11:39 schrieb Michel Dänzer:
> On 2017-12-19 11:37 AM, Michel Dänzer wrote:
>> On 2017-12-18 08:01 PM, Tobias Klausmann wrote:
>>> On 12/18/17 7:06 PM, Mike Galbraith wrote:
>>>> Greetings,
>>>>
>>>> Kernel bound workloads seem to trigger the below for whatever
reason.
>>>>    I only see this when beating up NFS.  There was a kworker
wakeup
>>>> latency issue, but with a bandaid applied to fix that up, I can
still
>>>> trigger this.
>>>
>>> Hi,
>>>
>>> i have seen this one as well with my system, but i could not find
an
>>> easy way to trigger it for bisecting purpose. If you can trigger it
>>> conveniently, a bisect would be nice!
>> I'm seeing this (with the amdgpu and radeon drivers) when restic
takes a
>> backup, creating memory pressure. I happen to have just finished
>> bisecting, the result is:
>>
>> 648bc3574716400acc06f99915815f80d9563783 is the first bad commit
>> commit 648bc3574716400acc06f99915815f80d9563783
>> Author: Christian König <christian.koenig at amd.com>
>> Date:   Thu Jul 6 09:59:43 2017 +0200
>>
>>      drm/ttm: add transparent huge page support for DMA allocations v2
>>
>>      Try to allocate huge pages when it makes sense.
>>
>>      v2: fix comment and use ifdef
>>
>>
> BTW, I haven't noticed any bad effects other than the dmesg splats, so
> maybe it's just noise about transient failures for which there is a
> proper fallback in place.
Yeah, I think that is exactly what happens here.

We try to allocate a huge page, but fail and so fall back to using 
multiple 4k pages instead.

Going to send out a patch to suppress the warning.

Thanks for bisecting this,
Christian.

On Tue, Dec 19, 2017 at 8:45 AM, Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
> Am 19.12.2017 um 11:39 schrieb Michel Dänzer:
>>
>> On 2017-12-19 11:37 AM, Michel Dänzer wrote:
>>>
>>> On 2017-12-18 08:01 PM, Tobias Klausmann wrote:
>>>>
>>>> On 12/18/17 7:06 PM, Mike Galbraith wrote:
>>>>>
>>>>> Greetings,
>>>>>
>>>>> Kernel bound workloads seem to trigger the below for
whatever reason.
>>>>>    I only see this when beating up NFS.  There was a
kworker wakeup
>>>>> latency issue, but with a bandaid applied to fix that up, I
can still
>>>>> trigger this.
>>>>
>>>>
>>>> Hi,
>>>>
>>>> i have seen this one as well with my system, but i could not
find an
>>>> easy way to trigger it for bisecting purpose. If you can
trigger it
>>>> conveniently, a bisect would be nice!
>>>
>>> I'm seeing this (with the amdgpu and radeon drivers) when
restic takes a
>>> backup, creating memory pressure. I happen to have just finished
>>> bisecting, the result is:
>>>
>>> 648bc3574716400acc06f99915815f80d9563783 is the first bad commit
>>> commit 648bc3574716400acc06f99915815f80d9563783
>>> Author: Christian König <christian.koenig at amd.com>
>>> Date:   Thu Jul 6 09:59:43 2017 +0200
>>>
>>>      drm/ttm: add transparent huge page support for DMA allocations
v2
>>>
>>>      Try to allocate huge pages when it makes sense.
>>>
>>>      v2: fix comment and use ifdef
>>>
>>>
>> BTW, I haven't noticed any bad effects other than the dmesg splats,
so
>> maybe it's just noise about transient failures for which there is a
>> proper fallback in place.
>
>
> Yeah, I think that is exactly what happens here.
>
> We try to allocate a huge page, but fail and so fall back to using multiple
> 4k pages instead.
>
> Going to send out a patch to suppress the warning.
Hi Christian,

Did you ever send out such a patch? I didn't see one on the list, but
perhaps I missed it. One definitely hasn't made it upstream yet. (I
just hit the issue myself with Linus's tree from last night.)

Thanks,

  -ilia

On Sun, 2017-12-31 at 13:27 -0500, Ilia Mirkin wrote:
> On Tue, Dec 19, 2017 at 8:45 AM, Christian König
> <ckoenig.leichtzumerken at gmail.com> wrote:
> > Am 19.12.2017 um 11:39 schrieb Michel Dänzer:
> >>
> >> On 2017-12-19 11:37 AM, Michel Dänzer wrote:
> >>>
> >>> On 2017-12-18 08:01 PM, Tobias Klausmann wrote:
> >>>>
> >>>> On 12/18/17 7:06 PM, Mike Galbraith wrote:
> >>>>>
> >>>>> Greetings,
> >>>>>
> >>>>> Kernel bound workloads seem to trigger the below for
whatever reason.
> >>>>>    I only see this when beating up NFS.  There was a
kworker wakeup
> >>>>> latency issue, but with a bandaid applied to fix that
up, I can still
> >>>>> trigger this.
> >>>>
> >>>>
> >>>> Hi,
> >>>>
> >>>> i have seen this one as well with my system, but i could
not find an
> >>>> easy way to trigger it for bisecting purpose. If you can
trigger it
> >>>> conveniently, a bisect would be nice!
> >>>
> >>> I'm seeing this (with the amdgpu and radeon drivers) when
restic takes a
> >>> backup, creating memory pressure. I happen to have just
finished
> >>> bisecting, the result is:
> >>>
> >>> 648bc3574716400acc06f99915815f80d9563783 is the first bad
commit
> >>> commit 648bc3574716400acc06f99915815f80d9563783
> >>> Author: Christian König <christian.koenig at amd.com>
> >>> Date:   Thu Jul 6 09:59:43 2017 +0200
> >>>
> >>>      drm/ttm: add transparent huge page support for DMA
allocations v2
> >>>
> >>>      Try to allocate huge pages when it makes sense.
> >>>
> >>>      v2: fix comment and use ifdef
> >>>
> >>>
> >> BTW, I haven't noticed any bad effects other than the dmesg
splats, so
> >> maybe it's just noise about transient failures for which there
is a
> >> proper fallback in place.
> >
> >
> > Yeah, I think that is exactly what happens here.
> >
> > We try to allocate a huge page, but fail and so fall back to using
multiple
> > 4k pages instead.
> >
> > Going to send out a patch to suppress the warning.
> 
> Hi Christian,
> 
> Did you ever send out such a patch? I didn't see one on the list, but
> perhaps I missed it. One definitely hasn't made it upstream yet. (I
> just hit the issue myself with Linus's tree from last night.)
Actually, that wants a bit more methinks, because while the stack dump
goes away, you still get spammed, it just comes in smaller chunks.

	-Mike