[linux-audio-user] Squeezing any more performance out of this old laptop...

[Spencer Russell]

With all this talk about laptops, I was wondering if there's anything
I can do to make mine usable. My main audio computer has been on the
fritz recently, so I'd like to be able to work with my laptop while
I'm troubleshooting. The problem is that the best latency I can get is
2x1024 frames, which comes out to 42.7 ms at 48000 Hz. This is clearly
not usable for live processing work. The laptop is a couple years old,
and has a 1GHz AMD Duron processor and 256MB of RAM.

I've got a 2.6.20 kernel patched with ingo's RT patch, set to full
preemption, and with all power management disabled. I'm using Debian's
most recent PAM package to give my regular user realtime privileges
and the following in my limits.conf:

@audio          -       rtprio 99
@audio          -       memlock 100000
@audio          -       nice -10

Jackd doesn't complain about not being able to get realtime, so I
think that's working. Also, when I use chrt to look at the priorities
of the jackd threads, there are 2 of them running SCHED_FIFO with
priorities of 20 and 10.

/proc/interrupts tells me that VIA686A (my onboard chipset) is the
only thing on IRQ10, and chrt tells me that IRQ10 is running
SCHED_FIFO at priority 50, as are all the other IRQ threads. Boosting
the priority to 60 doesn't seem to make a difference.

Is there anything more I can do?

Thanks,
spencer