BFQ I/O Scheduler Queued For Linux 4.12

[DrYak]

And here I wonder when Debian will finish with 9.0 so I can try out 4.10.

Newer kernel will be available from backports anyway. (That's how I'm getting my kernels on Debian Jessie)

i moved to blkmq sometime back and enabled it on all layers dm/scsi. i found it to perform better than bfq at least for this use case

Enabling blk-mq just disables scheduling at all now. So, congratulations, CFQ has nothing to do with this.

As far as I've understood BFQ's author (paolo)'s page : BFQ *is* the only scheduler available in blkmq.

Part of the reason why it took so long to get BFQ into mainstream is that the author was required to re-wire it for blk-mq (on the grounds that the older queue is going to be depracated at some point in the future)

[geearf]

Newer kernel will be available from backports anyway. (That's how I'm getting my kernels on Debian Jessie)





As far as I've understood BFQ's author (paolo)'s page : BFQ *is* the only scheduler available in blkmq.

Part of the reason why it took so long to get BFQ into mainstream is that the author was required to re-wire it for blk-mq (on the grounds that the older queue is going to be depracated at some point in the future)

There's been a port of deadline as well during the changes to blkmq, but I don't know if it was pushed to the kernel sources or not.
I think that's also another big news here, we now have blkmq supporting schedulers!

[sarfarazahmad]

DrYak yep quickly read through that page. i dont see any mention of bfq for blk mq. last i checked blk mq had no io schedulers and therefore it is told to have poor io performance on hdd (https://lkml.org/lkml/2015/11/25/744) but since i use hdd only as a last resort data store it works out alright

[post-factum]

As far as I've understood BFQ's author (paolo)'s page : BFQ *is* the only scheduler available in blkmq.

Now — yes. But in future no. 4.11 will introduce mq-deadline. 4.12 will introduce Kyber. So it would be 3 -mq schedulers in total in 4.12.

[nanonyme]

Why BFQ won't be the default scheduler?

It seriously doesn't matter what the default is as long as it's acceptable for all workloads. (doesn't need to be the best) You can set override as kernel parameter and eg grub2 in most distro integrations supports automatically appending hardcoded variables onto kernel lines so it will stick over kernel upgrasese

[Azrael5]

It seriously doesn't matter what the default is as long as it's acceptable for all workloads. (doesn't need to be the best) You can set override as kernel parameter and eg grub2 in most distro integrations supports automatically appending hardcoded variables onto kernel lines so it will stick over kernel upgrasese

Are you able to make this?

[starshipeleven]

Are you able to make this?

Unsure of what you are asking for. You can change default scheduler on boot by adding "elevator=scheduler-name-here" to your kernel command line.
http://www.techrepublic.com/article/...it-your-needs/

The kernel should accept that kernel command line argument as long as there is more than 1 scheduler. So as long as your distro mantainers don't disable it for lulz it should be easy to use it even if not default.

[Cape]

This post is sponsored by the BFQgang

"CFQ is kill! Go Paolo, go!"
- The BFQgang

:horn:, :horn: :horn: :horn: :horn:, :horn:, :horn: