On Jan 5, 2021, at 11:45 AM, Andrea Arcangeli [off-list ref] wrote:

On Tue, Jan 05, 2021 at 07:05:22PM +0000, Nadav Amit wrote:

quoted

quoted

On Jan 5, 2021, at 10:45 AM, Andrea Arcangeli [off-list ref] wrote:
I just don't like to slow down a feature required in the future for
implementing postcopy live snapshotting or other snapshots to userland
processes (for the non-KVM case, also unprivileged by default if using
bounce buffers to feed the syscalls) that can be used by open source
hypervisors to beat proprietary hypervisors like vmware.

Ouch, that’s uncalled for. I am sure that you understand that I have no
hidden agenda and we all have the same goal.

Ehm I never said you had an hidden agenda, so I'm not exactly why
you're accusing me of something I never said.

I merely pointed out one relevant justification for increasing kernel
complexity here by not slowing down clear_refs longstanding O(N)
clear_refs/softdirty feature and the recent uffd-wp O(1) feature, is
to be more competitive with proprietary software solutions, since
at least for uffd-wp, postcopy live snapshotting that the #1 use
case.

I never questioned your contribution or your preference, to be even
more explicit, it never crossed my mind that you have an hidden
agenda.

However since everyone already acked your patches and I'm not ok with
your patches because they will give a hit to KVM postcopy live
snapshotting and other container clear_refs users, I have to justify
why I NAK your patches and remaining competitive with proprietary
hypervisors is one of them, so I don't see what is wrong to state a
tangible end goal here.

I fully understand your objection to my patches and it is a valid
objection, which I will address.

I just thought that there might be some insinuation, as you mentioned VMware
by name. My response was half-jokingly and should have had a smiley to
prevent you from wasting your time on the explanation.