On 7/16/2014 9:11 AM, Chris Cappuccio wrote:
Josh Hoppes [josh.hop...@gmail.com] wrote:
Hello, I've got a few machines I'm setting up which I noticed ACPI0 is
generating a lot of constant interrupts which appears to be consuming
system time on CPU0 up to 80%. I think other interrupts are still
getting time to process, but I'm not sure if it could still cause a
performance impact as I'm looking to use these systems to handle
filtering and queuing on the edge of our network. Any ideas or
suggestions would be appreciated.
For your interrupt storm, you might want to test the latest BIOS and/or
the latest OpenBSD snapshot to see where things are at.
For your system in general, you'll get the best performance by disabling
hyper-threading, and if your CPU supports "turbo" mode, enable that.
I was just seeing the same issue when setting up a couple of R320s (with
latest BIOS) for similar purpose.
I was going to try a later snapshot, but thought I'd dig a bit more
first, since I was sure this wasn't happening when first installed. I
found that the ACPI interrupts started when I changed the BIOS system
profile from the default "Performance per watt" to plain "Performance".
Reverting that setting made things go back to normal.
The "Performance" profile made these changes:
CPU power management "System DBPM (DAPC)" -> "Maximum performance"
C1E -> disabled
C states -> disabled.
A quick check through the permutations shows that having cpu power
management set other than "System DBPM (DAPC)" causes the issue.
Don't know if that's of any interest, I'm probably going to try a newer
snapshot anyway now!
Graham
