Re: userspace irq balancer

Martin J. Bligh
2003-05-20T05:40:27Z

--Dave Hansen <haveblue@us.ibm.com> wrote (on Monday, May 19, 2003 22:03:50 -0700):

> On Mon, 2003-05-19 at 20:46, William Lee Irwin III wrote:
>> On Mon, May 19, 2003 at 08:25:31PM -0700, David S. Miller wrote:
>> > The in-kernel stuff MUST go. It went in because "some benchmark went
>> > faster", but with no "why" describing why it might have improved
>> > performance. We KNOW it absolutely sucks for routing and firewall
>> > applications. The in-kernel bits were all a shamans dance, with zero
>> > technical "here is why this makes things go faster" description
>> > attached. If I remember properly, the changelog message when the
>> > in-kernel irq balancing went in was of the form "this makes some
>> > specweb run go faster".
>>
>> Absolutely. Not to mention the code for the in-kernel algorithm has
>> historically broken i386 ports using certain modes of Intel's
>> interrupt controllers.
>
> OK, I just went and actually looked at the code again. After
> suppressing my gag reflex, I started to remember all of the problems
> we've had with it, including fixing it for Intel's own clustered APIC
> mode.
>
> Does anyone have a patch to tear it out already? Is the current proc
> interface acceptable, or do we want a syscall interface like wli
> suggests?

I have no frigging idea why you'd want to tear something out that works
well already, and has a shitload of work put into it.

Make it a config option if you don't like it, Keith has a patch to do
that already - it's trivial. That way everyone can have what they want.

M.