I expect that honestly the answer in Go is that if you're even tempted to use this, you are doing at least one of 1. premature optimization or 2. experiencing the consequences of choosing the wrong programming language for your project.
Language selection is really important and I think too many engineers approach it rather willy-nilly and with way too much bias towards what they like or may already know. Both of those are legitimate considerations! But they shouldn't be determinative. You need to calmly and rationally look at all the tradeoffs the languages offer. I think the vast majority of projects that have the sort of performance requirements that require arenas to function could have had that requirement determined from the beginning and the conclusion reached that Go was not a good choice, despite matching on some criteria. If this degree of memory performance is a critical requirement for your project, you're looking at a list of possible languages I could count with one hand, and Go's not on it.
(Though based on what I see in the world right now, the more common problem is people getting a project and grotesquely overestimating the performance they need, like, the guy tasked with writing a web site that will perform up to 5 entire CRUD updates per second at maximum load posting questions about whether they need the web framework that does six million requests per second or the one that does ten million. But both over and under estimating requirements is a problem in the real world.)
I would think not twice, but more like a dozen times about using a package like this. I would need to be backed into it by sheer desperation, some large code base that I simply can not fix any other way, or extract this into its external service/microservice/library for the task, or literally almost anything else, and using it would represent my program reaching the end of its "design budget", if not exceeding it.
And unless the decision was just so far back in the mists of history that it is completely irrelevant now (e.g., the decisions were all made by people no longer on the project), there'd be a postmortem on how we made the mistake of picking an inappropriate language.
Language selection is really important and I think too many engineers approach it rather willy-nilly and with way too much bias towards what they like or may already know. Both of those are legitimate considerations! But they shouldn't be determinative. You need to calmly and rationally look at all the tradeoffs the languages offer. I think the vast majority of projects that have the sort of performance requirements that require arenas to function could have had that requirement determined from the beginning and the conclusion reached that Go was not a good choice, despite matching on some criteria. If this degree of memory performance is a critical requirement for your project, you're looking at a list of possible languages I could count with one hand, and Go's not on it.
(Though based on what I see in the world right now, the more common problem is people getting a project and grotesquely overestimating the performance they need, like, the guy tasked with writing a web site that will perform up to 5 entire CRUD updates per second at maximum load posting questions about whether they need the web framework that does six million requests per second or the one that does ten million. But both over and under estimating requirements is a problem in the real world.)
I would think not twice, but more like a dozen times about using a package like this. I would need to be backed into it by sheer desperation, some large code base that I simply can not fix any other way, or extract this into its external service/microservice/library for the task, or literally almost anything else, and using it would represent my program reaching the end of its "design budget", if not exceeding it.
And unless the decision was just so far back in the mists of history that it is completely irrelevant now (e.g., the decisions were all made by people no longer on the project), there'd be a postmortem on how we made the mistake of picking an inappropriate language.