Ben Greear wrote:
I have a via motherboard with C3 processor and some real-tek NICs. I noticed
when using the top-of-tree that performance on it sucked (30Mbps v/s 54Mbps
network throughput in one pertinent test).
After several hours of bisecting, I see this as the culprit:
7b37b5fd9ba32c0c5afc3537eed7e7466f2173e2 is first bad commit
commit 7b37b5fd9ba32c0c5afc3537eed7e7466f2173e2
Author: Len Brown [off-list ref]
Date: Tue Dec 23 01:47:42 2008 -0500
ACPI: disable MPS when NO APIC-table found
When ACPI is asked to find an MADT (APIC table)
and fails, then ACPI expects to run in PIC mode.
However, if an MP Table is was found, IRQs will be
registered as if an IOAPIC is being used, even
though ACPI is configuring interrupt links links for PIC mode.
In this scenario, disable MPS so that IRQs
are registered in PIC mode, consistent with ACPI.
http://bugzilla.kernel.org/show_bug.cgi?id=12257
Signed-off-by: Len Brown [off-list ref]
:040000 040000 86ce74daee3a9fe6ff21ef7f8fb364af23ec0c1e 364933dfec0df34e63b1aeff6aff4092d421886b M arch
In addition, I see this warning in my logs, which is likely the symptom:
ACPI Exception (tbxface-0627): AE_NO_ACPI_TABLES, While loading namespace from ACPI tables ]
ACPI: Unable to load the System Description Tables
You're getting this on boot:
ACPI Error (tbxfroot-0218): A valid RSDP was not found [20080926]
That essentially means ACPI isn't working at all, I think. Did previous kernels produce this error? Do you have ACPI disabled in the BIOS or something?