92f5755f2b
On high-end systems running async sequential write workloads, especially NUMA systems with flash or NVMe storage, one significant performance bottleneck is selecting a metaslab to do allocations from. This process can be parallelized, providing significant performance increases for these workloads. illumos/illumos-gate@f78cdc34af Reviewed by: Matthew Ahrens <mahrens@delphix.com> Reviewed by: George Wilson <george.wilson@delphix.com> Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com> Reviewed by: Alexander Motin <mav@FreeBSD.org> Approved by: Gordon Ross <gwr@nexenta.com> Author: Paul Dagnelie <pcd@delphix.com>