On Mon, Oct 21, 2024 at 10:05:23PM +0300, Michael Tokarev wrote: > 21.10.2024 17:37, Peter Xu wrote: > > Michael, > > > > On Fri, Oct 18, 2024 at 06:38:53PM +0300, Michael Tokarev wrote: > > > Looking at this from qemu-stable PoV, I'm not 100% sure this change is > > > good > > > for stable-7.2 series, because 7.2 lacks v8.1.0-1571-g5b23186a95 > > > "kvm: Return number of free memslots" commit, which was a preparation for > > > for memory devices that consume multiple memslots. > > > > > > I did a backport of this change (currently it is at the tip of staging-7.2 > > > branch of https://gitlab.com/mjt0k/qemu.git) - I had to tweak context and > > > also to remove now-unused local variable in kvm-all.c. It builds and the > > > tests run fine, but I'm not really sure it does what it is intended to do. > > > > > > Should anything else be picked up for 7.2 for all this to work, or should > > > this change not be back-ported to 7.2 ? > > > > > > (for more recent releases, everything looks ok). > > > > I don't remember anything this series logically depends on (besides any > > context-wise change). > > Well, 7.2 is a bit old by now, and the commit I already mentioned above is > also quite old, - at the time you started working on this series, this > commit (v8.1.0-1571-g5b23186a95) has been in the tree for a long time > already. This change might be relevant here or might be not.
That specific commit (5b23186a95) shouldn't be relevant. > > > If there's uncertainty / challenge from backporting to some stable branches > > from your POV, we can still keep things simple and skip the series, as it's > > only a perf regression and only happens during live migrations (which can > > enlarge the downtime, for example) but not daily VM use. > > For this change alone, I did the backport, I just am not sure it makes sense. > > It would be great if you take a look, including the change I mentioned above > (it isn't in 7.2), there: https://gitlab.com/mjt0k/qemu/-/commits/staging-7.2 > Or we can just drop it for 7.2 per the above. I checked the backport, it looks all good. Thanks, -- Peter Xu
