On Tue, 27 Jul 2021 09:31:33 -0700 Evan Green <evgreen@xxxxxxxxxxxx> wrote: > > Pavel just mentioned uswsusp, and I wonder if it would be a possible > > alternative to this patch. > > I think you're right that it would be possible to isolate the > hibernate image with uswsusp if you avoid using the SNAPSHOT_*SWAP* > ioctls. But I'd expect performance to suffer noticeably, since now > every page is making a round trip out to usermode and back. I'd still > very much use the HIBERNATE_ONLY flag if it were accepted, I think > there's value to it. The uswsusp option makes your patch a performance optimization rather than a feature-add. And we do like to see quantitative testing results when considering a performance optimization. Especially when the performance optimization is a bit icky, putting special-case testing all over the place, maintenance cost, additional testing effort, etc. I do think that diligence demands that we quantify the difference. Is this a thing you can help with?
