[linux-audio-user] Linux for live performance
Frank Barknecht
fbar at footils.org
Wed Mar 29 04:07:23 EST 2006
Hallo,
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:
http://msdn.microsoft.com/library/en-us/dnxpembed/html/hardrealtime.asp?frame=true
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
setup.
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.
Ciao
--
Frank Barknecht _ ______footils.org_ __goto10.org__
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