OS-7416: bhyve BLOCKIF_NUMTHR should keep pace with MAXREQ


Issue Type:Improvement
Priority:4 - Normal
Created at:2018-12-03T19:00:46.517Z
Updated at:2018-12-03T22:58:07.973Z


Created by:Patrick Mooney [X]
Reported by:Patrick Mooney [X]
Assigned to:Patrick Mooney [X]


Fixed: A fix for this issue is checked into the tree and tested.
(Resolution Date: 2018-12-03T22:58:00.760Z)

Fix Versions

2018-12-06 Grizz (Release Date: 2018-12-06)

Related Links




In OS-7175, BLOCKIF_MAXREQ was increased in order to appease Windows virtio-blk consumers. The BLOCKIF_NUMTHR limit was not increased at the same time. Without a similar increase, threads would have potentially double the number of outstanding IOs. Increasing BLOCKIF_NUMTHR to match the MAXREQ scaling should be relatively cheap (a few extra threads and their associated resources) and could help IO throughput on fast backing devices.


Comment by Jira Bot
Created at 2018-12-03T22:58:07.973Z

illumos-joyent commit 09d9ee89aec409242d50a5e168d8d883fc7539e8 (branch master, by Patrick Mooney)

OS-7300 bhyve should not sync IO unless necessary
OS-7416 bhyve BLOCKIF_NUMTHR should keep pace with MAXREQ
Reviewed by: Robert Mustacchi <rm@joyent.com>
Reviewed by: Mike Gerdts <mike.gerdts@joyent.com>
Approved by: Mike Gerdts <mike.gerdts@joyent.com>