Arch Linux

archbaby

Member

Registered: 2022-09-02

Posts: 20

[SOLVED] How do I install the CFQ IO scheduler?

$ cat /sys/block/sdb/queue/scheduler
[none] mq-deadline kyber bfq

As you can see from the output of cat /sys/block/sdb/queue/scheduler, the CFQ IO scheduler is not there.
Now How do I install it?
Or is it already installed but not enabled?
Do I have to use another kernel version from the Arch repo?
Or do I have to compile a kernel version from kernel.org?

I'm currently using linux-lts 5.15.64-1 from the Arch repo.

Here are the outputs of the uname command:

$ uname -a
Linux ArchBaby 5.15.64-1-lts #1 SMP Wed, 31 Aug 2022 17:46:31 +0000 x86_64 GNU/Linux

$ uname -r
5.15.64-1-lts

Oh, and I'm using the "none" scheduler because I tried mq-deadline, kyber, and bfq, and "none" seemed to worked better with my slow USB stick (where I have Arch installed). I couldn't try out CFQ because it's not on the list.

I just want to know how to get the CFQ IO scheduler on Arch.

Thanks for all the help in advance.

Last edited by archbaby (2022-09-26 10:24:27)

stanczew

Member

Registered: 2021-03-02

Posts: 63

Re: [SOLVED] How do I install the CFQ IO scheduler?

CFQ was removed in 5.0:
https://en.wikipedia.org/wiki/Completel … 019-03-03)
https://git.kernel.org/pub/scm/linux/ke … 7883d4f217

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,645

Re: [SOLVED] How do I install the CFQ IO scheduler?

BFQ maps the most to what CFQ used to be and has similar scheduling policies support for setting batch io and the like.

archbaby

Member

Registered: 2022-09-02

Posts: 20

Re: [SOLVED] How do I install the CFQ IO scheduler?

Thanks, stanczew and V1del, for the answers. Love you both!

How do I mark a a question "answered or solved"? Do I edit and append "[solved]" to the post's subject?

Last edited by archbaby (2022-09-23 08:38:13)

archbaby

Member

Registered: 2022-09-02

Posts: 20

Re: [SOLVED] How do I install the CFQ IO scheduler?

Oh, and one more question: is using "none" as my IO scheduler safe?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 21,645

Re: [SOLVED] How do I install the CFQ IO scheduler?

Yes add it ot the title by editing your first post. Depends on how you define "safe" none simply means your USB will be given all IO directly with any scheduling/priorisation happening that's generally not a pleasant experience on a slow USB stick if you do a lot of IO but it shouldn't be inherently more dangerous than doing anything else (... all of the writes will happen eventually anyway) the main benefits of the schedulers are mostly visible on HDDs to optimize head seek/movment times.