Messages in this thread | | | Date | Tue, 12 Apr 2022 09:08:43 -0700 | From | Dave Hansen <> | Subject | Re: [PATCHv4 1/8] mm: Add support for unaccepted memory |
| |
On 4/12/22 01:15, David Hildenbrand wrote: > Can we simply automate this using a kthread or smth like that, which > just traverses the free page lists and accepts pages (similar, but > different to free page reporting)?
That's definitely doable.
The downside is that this will force premature consumption of physical memory resources that the guest may never use. That's a particular problem on TDX systems since there is no way for a VMM to reclaim guest memory short of killing the guest.
In other words, I can see a good argument either way: 1. The kernel should accept everything to avoid the perf nastiness 2. The kernel should accept only what it needs in order to reduce memory use
I'm kinda partial to #1 though, if I had to pick only one.
The other option might be to tie this all to DEFERRED_STRUCT_PAGE_INIT. Have the rule that everything that gets a 'struct page' must be accepted. If you want to do delayed acceptance, you do it via DEFERRED_STRUCT_PAGE_INIT.
| |