Re: [PATCH v3 4/5] x86/sgx: Replace section->page_list with a global free page list

[Dave Hansen]

On 3/3/21 7:03 AM, Jarkko Sakkinen wrote:
> Background
> ==========
> 
> EPC section is covered by one or more SRAT entries that are associated with
> one and only one PXM (NUMA node). The current implementation overheats a

Overheats?

> single NUMA node, because sgx_alloc_epc_page() always starts looking for
> pages from the same EPC section everytime.

"every time"

> Only within a section it does pick pages in FIFO fashion, i.e. the oldest
> freed in that section is the EPC page given back to the caller.  That does
> not do any good, as the pages in the same node are performance-wise equal.

I'm not sure why all of this is relevant and it doesn't really tell me
anything about this patch's place in the *series*.

Why are we destroying all of the per-node structures just before adding
NUMA support?

> Replace local lists with a single global free page list, from which pages
> are borrowed in FIFO fashion.