Subject: Re: splx() optimization [was Re: SMP re-eetrancy in "bottom half"
To: None <jonathan@dsg.stanford.edu>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: tech-kern
Date: 06/08/2005 07:56:19
> >> Besides, I'm impatient, I want to start working on SMP-safe network
> >> drivers, oh, last month.
> >
> >then, why don't you learn and work on audio drivers?
> 
> Because, I personally, have basically zero interest in SMP audio
> drivers??  (btw, I feel reasonably sure I said so, the last time you
> suggested audio.)

then why don't you just lower IPL_AUDIO in your local tree?

> On the other hand, I have considerable interest in delivering 10Gbit
> of TCP traffic -- or as close as I can get. And I'm very, _very_ sure
> that I can get closer by using more CPUs.

what you're saying here is that you want performance but
are not intersted in necessary work (== audio).
i don't think it's reasonable.

besides, i don't think you can achieve your desired performance with
lock-per-IPL.  the frequent locking due to spl operations will easily kill
any performance benefits from concurrency.

YAMAMOTO Takashi