Re: a joint letter on low latency and Linux

[Ingo Molnar]

On Thu, 29 Jun 2000, Paul Barton-Davis wrote:

> I am a little confused, Ingo. There were several exchanges that you
> had with Linus about the patches in which you put forward several
> arguments in favor of their inclusion. These culminated in Linus
> saying point blank that he would not do so.

that was a completely different patch. It was a different approach than
the 'low latency patch', it was about making the kernel preemptable.
Making a kernel preemptable is not an easy area, so disagreement was IMO
natural.

I'm going to do the same lowlatency patch for 2.4 what i did for 2.2. Note
that 2.4 already has a couple of lowlatency-related enhancements. (i
remember Andrea has added a better swapinfo/meminfo algorithm some time
ago for exactly this reason - and other areas improved as well.)

Btw., the lowlatency patch was written via looking at latency-profiling
output, where i used Benno's soundcard-latency-testing utility on a real
soundcard. That is a latency area we really care about. I didnt use
lmbench for _this_ patch btw., because the 'did the soundcard skip a
buffer, and how many times' metric is that i think is the most RL-relevant
number.

	Ingo