Re: [PATCH v3 1/8] KVM: selftests: Create a demand paging test

From: Andrew Jones
Date: Wed Jan 08 2020 - 08:45:32 EST


On Tue, Jan 07, 2020 at 10:41:55AM -0800, Ben Gardon wrote:
> I'll try to implement Drew's suggestion re: syncing global variables
> and then looking up CPU ID. If I can do that I'll upload another patch
> set for s390, aarch64, and x86. If I can't I'll move this test to the
> x86 subdirectory.
>
> I apologize for not responding to the comments on the previous version
> of this patch set. I'm still learning the mailing list etiquette. In
> the future is it preferable that I reply to those comments when I
> upload a new patch set addressing them, or should I add a note in the
> new patch emails about the comments I addressed in that update?

It's typically enough to just create a changelog in the cover letter.
E.g.

v3:
- Added ...
- Dropped ...
- Fixed ...
- Picked up r-b's

v2:
- Added ...
- Dropped ...
- Fixed ...
- Picked up r-b's

>
> I don't have any aarch64 or s390 hardware handy to test on so I'll try
> to move support for those architectures to separate commits at the end
> of the series, and mark them untested.

I'll test on aarch64, and I can also provide fixes if necessary.

Thanks,
drew

>
> Thank you for your quick responses!
>
> On Tue, Jan 7, 2020 at 6:56 AM Andrew Jones <drjones@xxxxxxxxxx> wrote:
> >
> > On Tue, Jan 07, 2020 at 09:33:34AM -0500, Peter Xu wrote:
> > > On Mon, Dec 16, 2019 at 01:38:54PM -0800, Ben Gardon wrote:
> > > > While userfaultfd, KVM's demand paging implementation, is not specific
> > > > to KVM, having a benchmark for its performance will be useful for
> > > > guiding performance improvements to KVM. As a first step towards creating
> > > > a userfaultfd demand paging test, create a simple memory access test,
> > > > based on dirty_log_test.
> > > >
> > > > Signed-off-by: Ben Gardon <bgardon@xxxxxxxxxx>
> > >
> > > It's fine to start with x86-only for this test, but imho it would be
> > > better to mention that in cover letter, or reply to reviewer comments
> > > on that you removed aarch64 from previous post.
> >
> > I'd also prefer that if it's x86-only that it be put in the x86_64
> > subdirectory and drop the arch #ifdefs. The question is why is it
> > x86-only for now though? Will it take a lot of work to port it to
> > other architectures? Or does it just need testing by someone with
> > the hardware?
> >
> > Thanks,
> > drew
> >
>