Re: low-latency patches

From: Robert Love (rml@tech9.net)
Date: Sat Oct 06 2001 - 17:22:09 EST


On Sat, 2001-10-06 at 18:00, Mike Fedyk wrote:
> And exactly how is low latency going to hurt the majority?

The problem is people argue that a preemptible kernel lowers throughput
since I/O is now interrupted. Of course, if they fear that, maybe we
should switch to cooperative multitasking!

Anyhow, tests show the preemptible kernel has a negligible effect on
throughput -- in fact in some cases we improve it since overtime we
better distribute system load. This is one reason why I ask for dbench
or bonnie benchmarks from the preemption users. Results are good.

The other concern is that added complexity is a Bad Thing, and I agree,
but the complexity of preemption is insanely low. In fact, since we use
so many preexisting constructs (such as SMP locks), its practically
nothing.

> This reminds me of when 4GB on ia32 was enough, or 16 bit UIDs, or...
>
> Should those have been left out too just because the people who needed them
> were few?

Agreed.

> If the requirements for manufacturing control, or audio processing, or etc
> will make my home box, or my server work better then why not include it?

That is my thought process, too.

        Robert Love

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sun Oct 07 2001 - 21:00:43 EST