Just a few days ago. Parabola GNU/Linux-libre (like Arch Linux). On btrfs, if that makes a difference.
From what I could tell, whatever the slow part is, it wasn't parallelized at all; of 16 cores, 15 were idle, and 1 was pegged at 100% (and very low disk-wait).
I've been meaning to dig in to this more. I'd tried adding --stream, figuring that maybe it was re-compressing the entire repo; but that just lead to a warning about "server doesn't support streams" or something like that. I'll definitely try ygra's suggestion to try --pull, and if that doesn't yield good results, I'll actually dig in to the sources and see what's going on.
From what I could tell, whatever the slow part is, it wasn't parallelized at all; of 16 cores, 15 were idle, and 1 was pegged at 100% (and very low disk-wait).
I've been meaning to dig in to this more. I'd tried adding --stream, figuring that maybe it was re-compressing the entire repo; but that just lead to a warning about "server doesn't support streams" or something like that. I'll definitely try ygra's suggestion to try --pull, and if that doesn't yield good results, I'll actually dig in to the sources and see what's going on.