# Installing ck-sources (USE=bfsonly)

## sdz

I am trying to install the BFS I/O scheduler.  However, it does not appear in the list of schedulers.

Also, I cannot find installation instructions in the package or online.  (Please provide link to documentation if mistaken.)

Before installation:

```

root ~ # uname -r

3.8.13-gentoo

root ~ # ll /usr/src/linux -d

lrwxrwxrwx 1 root root 19 May 19 12:34 /usr/src/linux -> linux-3.8.13-gentoo

```

Steps taken:

```

echo 'sys-kernel/ck-sources bfsonly' >> /etc/portage/package.use

echo '=sys-kernel/ck-sources-3.8.13 ~amd64' >> /etc/portage/package.keywords

emerge =sys-kernel/ck-sources-3.8.13

mount /boot

cd /usr/src/linux

make && make install

reboot

```

After reboot:

```

root ~ # cat /sys/block/sda/queue/scheduler 

noop [cfq] 

```

What are the installation instructions for ck-sources (with USE=bfsonly)?

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## aCOSwt

 *sdz wrote:*   

> I am trying to install the BFS I/O scheduler.  However, it does not appear in the list of schedulers...
> 
> ```
> 
> root ~ # cat /sys/block/sda/queue/scheduler 
> ...

 

I am afraid there is some misunderstanding.

BFS is a CPU scheduler, not an I/O scheduler.

If you actually want an I/O scheduler, then would you mean the BFQ ?

If yes then

 *sdz wrote:*   

> Installing ck-sources (USE=bfsonly)

 

wont be of any help.

The ck-sources / ck-patchset / ck-whatever have absolutely nothing to do with the BFQ that they even do not recommend as the preferred choice for queuing I/O.

I am not aware of any gentoo package installing the BFQ as a standalone or automagically patching your existing kernel-sources package.

So either you patch your gentoo-sources kernel yourself (you'll be on your own) or you use the sys-kernel/pf-sources linux fork which implements the BFQ and misc other things. (but take care, apart from the 3.9.2, I fear that all the releases made available are concerned with more or less severe security issues)

 *sdz wrote:*   

> What are the installation instructions for ck-sources (with USE=bfsonly)?

 

They are absolutely identical to those related to any gentoo supported kernel : http://www.gentoo.org/doc/en/handbook/handbook-amd64.xml?part=1&chap=7

For more details about the use flags, you can refer to : https://forums.gentoo.org/viewtopic-t-941030-start-0.html

These kernel sources actually implement the BFS cpu scheduler, but, once again, I do not understand from your post that this is what you want.

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