Re: CONFIG_PREEMPT and server workloads

[William Lee Irwin III <wli@holomorphy.com>]

On Wed, Mar 24, 2004 at 02:57:20PM +0100, Takashi Iwai wrote:
> 	http://www.alsa-project.org/~iwai/audio-latency.pdf
> the data there are already old (based on 2.6.0-test9), and were
> measured by the old version of latency-test program (modifed version
> from Benno Senor's latencytest suite).
> basically, the latency-test program measures the latency between the
> time of (periodical) irq and the time when user RT-thread is woken
> up under different workloads.  the user thread can perform an
> artificial CPU load (busy loop) to simulate the situation that any RT
> process does a heavy job.
> the resultant plot shows the critical deadline, the total latency and
> the CPU latency (busy loop) responses, as you can see in the above
> pdf.
> the latest version of latency-test suite is found at
> 	http://www.alsa-project.org/~iwai/latencytest-0.5.3.tar.gz
> it uses its own kernel module to generate irqs from RTC and to trace
> stacks.
> i'll show the results of the recent kernels tomorrow...

Very nice. This document is the kind of thing I wanted to see.


-- wli