Re: [linux-audio-user] Linux for live performance

From: Frank Barknecht <fbar@email-addr-hidden>
Date: Wed Mar 29 2006 - 12:07:23 EEST

Lee Revell hat gesagt: // Lee Revell wrote:
> Yes, in theory. So presumably if you found good anecdotal evidence that
> a given laptop is good for live audio with Windows it *should* be OK for
> Linux...

I found this, which mentions the System Management Mode (SMM) as well
as a source of realtime problems:

The subchapter "Hardware causes of ISR latency" says this:

  Power management, especially on portable devices, creates occasional
  long-latency events when the CPU is put in a low-power-consumption
  state after a period of inactivity. Such problems are usually quite
  easy to detect. A typical system can disable those features via BIOS
  Some systems, again typically notebooks, use the Pentium processor's
  System Management Mode (SMM) to perform specialized keystroke or
  other processing in BIOS firmware. While in SMM, the processor does
  not field interrupts that adds to ISR latencies.
  Fortunately new generations of system platforms, starting with ACPI
  platforms and Windows 2000, use the operating system and not BIOS,
  to provide power management. As a result, these sources of latency
  are now minimal.

The last paragraph indicates that there might be hope.


 Frank Barknecht                 _ ______footils.org_ __goto10.org__
Received on Wed Mar 29 12:15:09 2006

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