BLK-MQ Support For OpenZFS Pending As Latest Performance Optimization

Written by Michael Larabel in Linux Storage on 26 October 2021 at 05:34 AM EDT. 6 Comments
A new pull request is pending for implementing multi-queue block (blk-mq) support within OpenZFS' Zvol code, which can lead to sizable performance benefits.

Tony Hutter opened up the pull request at the end of last week for blk-mq support. Utilizing blk-mq allows for queuing and submitting I/O requests to block devices simultaneously. With modern multi-core CPUs and speedy storage devices, BLK-MQ can lead to very real benefits.

This change for the Zvol block driver allows for multiple queues on different processor cores rather than having a single request queue, which in turn can provide dramatic improvements in multi-threaded I/O workloads. The benchmarks range from a 6% to 252% improvement. Some of the non-O_DIRECT tests show a rather large improvement but in general many of the tests show a 14~24% improvement in throughput.

More details for those interested in blk-mq support for the OpenZFS Zvol code can see the pull request for all of the details on this pending improvement.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

Popular News This Week