On Fri, May 31, 2024 at 1:03 AM Oliver Upton oliver.upton@linux.dev wrote:
On Fri, May 31, 2024 at 12:05:48AM -0600, Yu Zhao wrote:
Let me add back what I said earlier:
I'm not convinced, but it doesn't mean your point of view is invalid. If you fully understand the implications of your design choice and document them, I will not object.
All optimizations in v2 were measured step by step. Even that bitmap, which might be considered overengineered, brought a readily measuarable 4% improvement in memcached throughput on Altra Max swapping to Optane:
That's great, but taking an iterative approach to the problem allows the reviewers and maintainers to come to their own conclusions about each optimization independently. Squashing all of that together and posting the result doesn't allow for this.
That's your methodology, which I respect: as I said I won't stand in your way.
But mine is backed by data, please do respect that as well, by doing what I asked: document your justifications.
Even if we were to take the series as-is, the door is wide open to subsequent improvements.
What I don't think is acceptable is simplifying those optimizations out without documenting your justifications (I would even call it a design change, rather than simplification, from v3 to v4).
No, sorry, there's nothing wrong with James' approach here.
Sorry, are you saying "without documenting your justifications" is nothing wrong? If so, please elaborate.
The discussion that led to the design of v4 happened on list; you were on CC. The general consensus on the KVM side was that the bitmap was complicated and lacked independent justification. There was ample opportunity to voice your concerns before he spent the time on v4.
Please re-read my previous emails -- I never object to the removal of the bitmap or James' approach.
And please stop making assumptions -- I did voice my concerns with James privately.
You seriously cannot fault a contributor for respinning their work based on the provided feedback.
Are you saying I faulted James for taking others' feedback? If so, where? And I'll make sure I don't give such an impression in the future.
Also what do you think about the technical flaws and inaccurate understandings I pointed out? You seem to have a strong opinion on your iterate approach, but I hope you didn't choose to overlook the real meat of this discussion.