Re: [PATCH] Time sliced CFQ #2

Jens Axboe
2004-12-06T07:14:20Z

On Sun, Dec 05 2004, Jeff Sipek wrote:
> On Sun, Dec 05, 2004 at 07:58:45PM +0100, Jens Axboe wrote:
> > It should be really easy to try some rudimentary prio io support - just
> > scale the time slice based on process priority. A few lines of code
> > change, and io priority now follows process cpu scheduler priority. To
> > work really well, the code probably needs a few more limits besides just
> > slice time.
>
> I started working on the rudimentary io prio code, and it got me
> thinking... Why use the cpu scheduler priorities? Wouldn't it make
> more sense to add io_prio to task_struct? This way you can have a
> process which you know needs a lot of CPU but not as much io, or the
> other way around.
>
> What do you think?

I don't like tieing them together, see various threads in the list
archives for discussions about that. I just said that it would be easy
to test basic support this way, since you only have to change a few
lines.

I've already posted the glue code to set/query process priorities, I
would plan on just using something like that again.

--
Jens Axboe