Re: [PATCH v5 11/18] x86/sgx: store unreclaimable pages in LRU lists

From: Haitao Huang
Date: Tue Oct 03 2023 - 01:43:19 EST


On Wed, 27 Sep 2023 06:57:18 -0500, Huang, Kai <kai.huang@xxxxxxxxx> wrote:

On Fri, 2023-09-22 at 20:06 -0700, Haitao Huang wrote:
From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>

When an OOM event occurs, all pages associated with an enclave will need
to be freed, including pages that are not currently tracked by the
cgroup LRU lists.

What are "cgroup LRU lists"?

Will reword it. At them moment there is only one global sgx_epc_lru_lists.

Add a new "unreclaimable" list to the sgx_epc_lru_lists struct and
update the "sgx_record/drop_epc_pages()" functions for adding/removing
VA and SECS pages to/from this "unreclaimable" list.

Sorry I don't follow the logic between the two paragraphs.

What is the exact problem? How does the new "unreclaimable" list solve the
problem?


Currently they are not tracked in a list managed by the ksgxd (future cgroup worker). So add a list to track them.
Thanks
Haitao