v3 vs v2

[Jura-Z]

Hey! Thanks for the great allocator, we're testing v3 and it is MUCH more better than v2.

Wondering where can I read more about the difference? Any risks in using v3 in production?

Thank you!

[skreborn]

The README says this about the dev3 branch (emphasis mine):

development branch for mimalloc v3-beta. This branch is downstream of dev. This version simplifies the lock-free ownership of previous versions, has no thread-local segments any more. This improves sharing of memory between threads, and on certain large workloads may use less memory with less fragmentation.

With that said, I'd love to know what needs to be done to get v3 over the finish line and declare it production ready.

[daanx]

I would say v3 is production ready as it is already running at large scale on some big services -- I will soon remove the beta tag. However, there are still some benchmarks (in Lean) where v3 performance is bit worse than v2 (~10 to 20%) and I would like to still address this. Generally though with the reduced memory usage, v3.1.5+ is nowadays preferable.

[pitrou]

@daanx I see that there are both v3.0.x and v3.1.x versions. Which one would you suggest?

[skreborn]

@pitrou In their previous comment, they mentioned that "Generally though with the reduced memory usage, v3.1.5+ is nowadays preferable."

[pitrou]

@pitrou In their previous comment, they mentioned that "Generally though with the reduced memory usage, v3.1.5+ is nowadays preferable."

That was answering the v3 vs. v2 question, but did not address the v3.0 vs. v3.1 question...

[skreborn]

I see that there was indeed a new 3.0.9 release about two weeks ago, but as far as I can tell, all the changes since the 3.0.8 version were those backported from the 3.1.x line. It's true, however, that those same changes to the 3.1.x line have not been tagged as a release yet—so in essence 3.0.9 contains fixes that came after 3.1.5 (even if those changes are available on the dev3 branch).

[pitrou]

Ok, thanks @skreborn . I'll try switching to v3.0.9 in Apache Arrow then.