On Thu, 29 Jun 2023 at 09:26, Tomas Vondra <tomas.von...@enterprisedb.com> wrote: > AllocSetContext 224B -> 208B (4 cachelines) > GenerationContext 152B -> 136B (3 cachelines) > SlabContext 200B -> 200B (no change, adds 4B hole) > > Nothing else changes, AFAICS.
I don't think a lack of a reduction in the number of cache lines is the important part. Allowing more space on the keeper block, which is at the end of the context struct seems more useful. I understand that the proposal is just to shave off 12 bytes and that's not exactly huge when it's just once per context, but we do create quite a large number of contexts with ALLOCSET_SMALL_SIZES which have a 1KB initial block size. 12 bytes in 1024 is not terrible. It's not exactly an invasive change. It does not add any complexity to the code and as far as I can see, about zero risk of it slowing anything down. David
