Re: [PATCH v4 03/18] x86/sgx: Add sgx_epc_lru_lists to encapsulate LRU lists

Haitao Huang
2023-09-15T16:28:28Z

On Thu, 14 Sep 2023 05:31:30 -0500, Huang, Kai <kai.huang@intel.com> wrote:

> Some non-technical staff:
>
> On Tue, 2023-09-12 at 21:06 -0700, Haitao Huang wrote:
>> From: Kristen Carlson Accardi <kristen@linux.intel.com>
>
> The patch was from Kristen, but ...
>
>>
>> Introduce a data structure to wrap the existing reclaimable list and its
>> spinlock. Each cgroup later will have one instance of this structure to
>> track EPC pages allocated for processes associated with the same cgroup.
>> Just like the global SGX reclaimer (ksgxd), an EPC cgroup reclaims pages
>> from the reclaimable list in this structure when its usage reaches near
>> its limit.
>>
>> Currently, ksgxd does not track the VA, SECS pages. They are considered
>> as 'unreclaimable' pages that are only deallocated when their respective
>> owning enclaves are destroyed and all associated resources released.
>>
>> When an EPC cgroup can not reclaim any more reclaimable EPC pages to
>> reduce its usage below its limit, the cgroup must also reclaim those
>> unreclaimables by killing their owning enclaves. The VA and SECS pages
>> later are also tracked in an 'unreclaimable' list added to this
>> structure
>> to support this OOM killing of enclaves.
>>
>> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
>> Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
>
> ... it was firstly signed by Sean and then Kristen, which doesn't sound
> right.
>
> If the patch was from Kristen, then either Sean's SoB should come after
> Kristen's (which means Sean took Kristen's patch and signed it), or you
> need to
> have a Co-developed-by tag for Sean right before his SoB (which
> indicates Sean
> participated in the development of the patch but likely he wasn't the
> main
> developer).
>
> But I _guess_ the patch was just from Sean.
>
From what I see:
In v1 kristen included a "From" tsg for Sean. In v2 she split the original
patch into two and added some wrappers/ At that time, she removed the
"From" tag for both patches but kept the SOB and CC.

@Kristen, could you confirm?

I only removed the wrappers from v2 based on Dave's comments.
So if confirmed by Kristen, should we add "From" tag for Sean?

I'll double check the other patches.
Thanks
Haitao