Re: [PATCH v2 0/3] dma-buf: heaps: cma: enable dmem cgroup accounting

[Shakeel Butt]

On Thu, Feb 26, 2026 at 12:32:42PM +0100, Christian König wrote:
> On 2/26/26 00:43, Dave Airlie wrote:
> >>>>
> 
> > If something is in the main memory pool, it should be accounted for
> > using memcg. You cannot remove memory from the main memory pool
> > without accounting for it.
> 
> That's what I'm strongly disagreeing on. See the page cache is not accounted to memcg either, so when you open a file and the kernel caches the backing pages that doesn't reduce the amount you can allocate through malloc, doesn't it?

Page cache is accounted/charged to memcg and usually it is reclaimable meaning
it most probably doesn't reduce the amount of anon memory you can allocate.

> 
> For dGPUs GTT is basically just the fallback when you over allocate local memory (plus a few things for uploads).
> 
> In other words system memory becomes the swap of device local memory. Just think about why memcg doesn't limits swap but only how much is swapped out.

What does "memcg doesn't limits swap" mean?