Re: [RFC 0/6] Module for tracking/accounting shared memory buffers

[Christian KÃnig]

Am 12.10.2016 um 01:50 schrieb Ruchi Kandoi:
> This patchstack adds memtrack hooks into dma-buf and ion.  If there's upstream
> interest in memtrack, it can be extended to other memory allocators as well,
> such as GEM implementations.
We have run into similar problems before. Because of this I already 
proposed a solution for this quite a while ago, but never pushed on 
upstreaming this since it was only done for a special use case.

Instead of keeping track of how much memory a process has bound (which 
is very fragile) my solution  only added some more debugging info on a 
per fd basis (e.g. how much memory is bound to this fd).

This information was then used by the OOM killer (for example) to make a 
better decision on which process to reap.

Shouldn't be to hard to expose this through debugfs or maybe a new fcntl 
to userspace for debugging.

I haven't looked at the code in detail, but messing with the per process 
memory accounting like you did in this proposal is clearly not a good 
idea if you ask me.

Regards,
Christian.