Hello,
On Tue, Jul 16, 2024 at 05:01:15PM +0000, Roman Gushchin wrote:
If we want to allow peak measurement of time periods, I wonder whether we could do something similar to pressure triggers - ie. let users register watchers so that each user can define their own watch periods. This is more involved but more useful and less error-inducing than adding reset to a single counter.
It's definitely a better user interface and I totally agree with you regarding the shortcomings of the proposed interface with a global reset. But if you let users to register a (potentially large) number of watchers, it might be quite bad for the overall performance, isn't it? To mitigate it, we'll need to reduce the accuracy of peak values. And then the question is why not just poll it periodically from userspace?
I haven't thought in detail but it's the same problem that PSI triggers have, right? PSI seems to have found a reasonable trade-off across accuracy, overhead and usage restrictions? Maybe peak usage isn't as widely useful and it doesn't justify to engineer something as sophisticated. I don't know.
Thanks.