Post #337550
2026-02-13 14:47 UTC
Had some quality time with claude debugging a slowness with AHCI/scsi and aio=io_uring. See below link for details (patch 1 is where it's at), but tldr is up to 60-80x improvement in performance for the case that hits ppoll idle all the time.
https://lore.kernel.org/qemu-devel/20260213143225.161043-1-axboe@kernel.dk/
Replies (1)
-
@axboe@fosstodon.org 2026-02-13 14:47
This took a while. One funny side quest was claude deciding it should check if my (destructive) reproducer was also slow on virtio-blk, then proceeding to blow away /dev/vda and concluded that yeah virtio-blk was fine. When confronted with this, it just said "Yes, I did do that". I then asked it to fix up vda, as it blew away the first 128MB of it. And it did.