On 4/17/25 4:06 AM, Yoav Cohen wrote: > Hi, > > I'm running ublk on Ubuntu Kenrel 6.8.0-56-generic. I notice that if > I'm running an IO commands that causing the IO queues to be full (at > least the ublk hw queue) it seems like some of the IO's are done 30 > seconds~ after they where submitted. Enlarging the IO queues fixed the > issue, and I'm pretty sure the 30 seconds magic number may be result > of blk_mq_tag_set timeout filed default(see > blk_mq_init_allocated_queue where it set to 30 * HZ) > > > Can you guys explain the behaviour? Please try a more recent kernel - 6.8 is both pretty old in terms of ublk, and more importantly, it's also not a supported stable release. That means that even if we could fix any issues in 6.8, since there's no further release of that, it's a dead end. The only one you can talk to about distro kernel issues is the distro. And I'm guessing you're using Ubuntu - they do have closer-to-mainline kernels available, that'd be a much better base to use. -- Jens Axboe
