Re: [PATCH v9 10/15] x86/sgx: Add EPC reclamation in cgroup try_charge()

Huang, Kai
2024-02-26T22:39:01Z

On 27/02/2024 11:31 am, Dave Hansen wrote:
> On 2/26/24 14:24, Huang, Kai wrote:
>> What is the downside of doing per-group reclaim when try_charge()
>> succeeds for the enclave but failed to allocate EPC page?
>>
>> Could you give an complete answer why you choose to use global reclaim
>> for the above case?
>
> There are literally two different limits at play. There's the limit
> that the cgroup imposes and then the actual physical limit.
>
> Hitting the cgroup limit induces cgroup reclaim.
>
> Hitting the physical limit induces global reclaim.
>
> Maybe I'm just being dense, but I fail to understand why you would want
> to entangle those two different concepts more than absolutely necessary.

OK. Yes I agree doing per-cgroup reclaim when hitting physical limit
would bring another layer of consideration of when to do global reclaim,
which is not necessary now.