The nvme cmd completion queue is contentious
When benchmarking for https://www.illumos.org/issues/11827 I discovered the mutex inside the taskq code which guards queue and un-queueing of of tasks is hot and heavily contended.
I propose there is one taskq per completion queue.
The testing results will be posted in 11827
Updated by Electric Monk over 2 years ago
- Status changed from In Progress to Closed
- % Done changed from 70 to 100
commit 4d95620bc3105916e69c40cff8e2e3d55bd6c4ae Author: Paul Winder <email@example.com> Date: 2019-11-21T16:46:27.000Z 11827 Increase concurrency through blkdev 11847 The nvme cmd completion queue is contentious Reviewed by: Robert Mustacchi <firstname.lastname@example.org> Reviewed by: Hans Rosenfeld <email@example.com> Reviewed by: Matthias Scheler <firstname.lastname@example.org> Approved by: Dan McDonald <email@example.com>