BFS vs CFS schedulers kernel?

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BFS vs CFS schedulers kernel?

Postby AstorBG » Nov 13th, '15, 13:55

Hi guys!
I know that M5 uses CFS scheduler. I just was wondering are there any particular advantages over BFS, specific for M5?
Some distros are using BFS but most distros use CFS. Is it for generality or support or ...?

Thx!
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Re: BFS vs CFS schedulers kernel?

Postby doktor5000 » Nov 13th, '15, 20:34

Well, probably the advantage that cfq scheduler is maintained upstream and bfs is an out-of-tree patchset. And that cfq is the default scheduler.
You should keep in mind that bfs is not intended to be a general-purpose scheduler. But it's still available in our kernel packages so you can use it if you want.

FWIW, I know only three distros offhand that are BFS-enabled ...

And related to your question:
http://askubuntu.com/questions/339951/w ... ntu-kernel
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Re: BFS vs CFS schedulers kernel?

Postby AstorBG » Nov 14th, '15, 10:29

Thanks dok! I thought so.

But I read somwhere that brain-fuck cpu scheduler (BFS) makes programs open/run slightly faster than
completely fair scheduler (CFS) but it's almost un-noticable form the user viewpoint. Anyway, I will stick to CFS.

Regards,,
Astor
Last edited by doktor5000 on Nov 14th, '15, 17:31, edited 1 time in total.
Reason: removed fullquote
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Re: BFS vs CFS schedulers kernel?

Postby doktor5000 » Nov 14th, '15, 17:33

Well you can easily switch the scheduler to BFS to see if it brings improvements for your installation.
See e.g. http://stackoverflow.com/questions/1009 ... -scheduler which links to upstream kernel documentation and explains how to switch the scheduler.
But keep in mind you have to load the module beforehand via
Code: Select all
modprobe bfs
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Re: BFS vs CFS schedulers kernel?

Postby ozky » Jan 18th, '16, 12:54

Thomas backlund aka tmb have enabled it in he own testing kernel build install it with this.
Code: Select all
urpmi kernel-tmb-desktop-latest

https://wiki.mageia.org/en/Kernel_flavo ... _.22tmb.22
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