Re: Performance/resume issues on Toshiba NB305

From: Burt Triplett
Date: Sun Feb 27 2011 - 15:18:17 EST

On 02/26/2011 07:00 AM, Seth Forshee wrote:
On Fri, Feb 25, 2011 at 09:58:25PM -0800, Burt Triplett wrote:
Looks like the Toshiba NB305 has an Intel Atom processor in it.
bits-327, released today, now detects Intel Atom processors, and no
longer shows them as unknown. We don't have any processor-specific
tests for Atom yet, though we may add some in the future. All of
the general tests should work, however.

The new release detects the Atom processor okay, but in bits-327 the
system resets during the SMI frequency/latency test, whereas it didn't
with bits-316.

The SMI Frequency and Latency test should be fixed in bits-329.

Can you provide more details on which MSRs show up as inconsistent
on your system? They might represent actual bugs in your BIOS, but
we might just need to add a few more entries to the Atom
CPU-specific MSR blacklist as expected inconsistencies.

Here's what it says:

(MSR 0x39 consistent): FAIL
(MSR 0x199 consistent): FAIL
(MSR 0x1a0 consistent): FAIL
Summary: 7917 passed, 3 failed

I have 3 systems with this same processor, and they all report the same
thing here.

To get more information on how the MSRs differ between CPUs, you can turn on verbose mode. Go to the GRUB command line by hitting 'c', and enter "test_options -v 2". Then hit Esc to go back to the menu, and re-run the MSR consistency check. It will now show you the value of the MSR on each CPU.

MSR 0x1a0 is IA32_MISC_ENABLE, and generally any inconsistency in that MSR represents a BIOS bug: it didn't enable features identically on all CPUs. Once you see which bits differ, you can look at the Intel Software Developer's Manual (specifically volume 3B) to find out what those bits mean and which specific features the BIOS inconsistently enabled.

MSR 0x199 is IA32_PERF_CTL. A difference in that MSR usually means the BIOS left CPUs in different P-states when booting, which it really shouldn't do. Again, you can decode the result with the Intel SDM.

Looking into MSR 0x39.

- Burt Triplett
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