GTT memory usage overflow

[Christian König]

Am 13.07.2018 um 09:40 schrieb Michel Dänzer:
> On 2018-07-13 09:00 AM, Christian König wrote:
>> Hi,
>>
>> no that is certainly not normal.
>>
>> We temporary allow the kernel to allocate more pages than available when
>> we bind stuff into the GART, but that shouldn't have this effect.
> mgr->available can happen to be negative when amdgpu_gtt_mgr_debug is
> called, can't it? I.e. we should clamp it to 0 there as well, same as in
> amdgpu_gtt_mgr_usage (or maybe just use that for both values in
> amdgpu_gtt_mgr_debug).

Yeah, but that happens only temporary while binding things into GART.

You must be really really lucky if you can see that in debugfs and from 
the description it sounds more like the reporter sees negative values 
all the time.

I really wonder how that could happen.

Christian.