Re: PATCH v4 0/6] mm, drm/ttm, drm/xe: Avoid reclaim/eviction loops under fragmentation

[Matthew Brost]

On Fri, May 01, 2026 at 01:05:57PM -0700, Kenneth Crudup wrote:
> 
> On 5/1/26 13:00, Matthew Brost wrote:
> 
> > So is this 7.1-rc1? It looks like new feature to 7.1 added by Dave [1] and
> > something look off here. Thanks for pointing this out.
> 
> Yeah. I grab his master branch daily (as of 6fe0be6dc7fa RN).
> 
> Is this a "shoot the messenger" thing? IOW, is the reporting off, or is the

I don't think I'm firing any shots.

> memory usage really that high?

I've been able to recreate this. It looks like accounting is correct
until the Xe shrinker runs - every time it kicks in GPUActive grows and
will not reduce past some new floor value. It looks like an accounting
bug in TTM or Xe (?).

Here is my output on a 8G PTL where I have intentionally triggered
shrinker to evict at least 23875 BOs (most likey quite few more but this
what I easily see in dmesg) after closing everything on desktop.

cat /proc/meminfo | grep GPU; cat /proc/buddyinfo;
GPUActive:      13100036 kB
GPUReclaim:          152 kB
Node 0, zone      DMA      0      1      0      0      0      0      0      0      1      1      3
Node 0, zone    DMA32   2320   1882   1523   1238    980    740    482    275    114     88    205
Node 0, zone   Normal   9751   9343   6466   4237   2703   1162    805    420    191    145    289

Let me spend a bit of time here to see if I figure out where the
accounting goes wrong.

Matt

> 
> (BTW, those are in 30-second intervals)
> 
> > > ----
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUActive:        652640 kB
> > > GPUReclaim:       403988 kB
> > > 
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUActive:        651180 kB
> > > GPUReclaim:       406812 kB
> > > 
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUActive:        659004 kB
> > > GPUReclaim:       399396 kB
> > > 
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUActive:        666996 kB
> > > GPUReclaim:       392764 kB
> > > 
> > > <some hours later>
> > > GPUActive:      91832468 kB
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUReclaim:       488000 kB
> > > 
> > > GPUActive:      91832332 kB
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUReclaim:       487988 kB
> > > 
> > > GPUActive:      91869376 kB
> > > SwapTotal:      33554428 kB
> > > MemTotal:       32345672 kB
> > > GPUReclaim:       486504 kB
> > > ----
> 
> -K
> 
> -- 
> Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange County
> CA
>