Messages in this thread | | | Subject | RE: powernow-k8: out of sync on Athlon64 x2 3800+ | Date | Wed, 1 Feb 2006 18:05:00 -0600 | From | "shin, jacob" <> |
| |
Hello,
I don't think this is a BIOS issue, but a kernel bug in the i386 tree. I believe this was recently discussed and hopefully fixed by Andi Kleen in the kernel mailing list:
http://lkml.org/lkml/2006/1/9/442
This is a critical bug especially for systems running AMD Dual-Core Processors on i386 kernel configuration w/ powernow-k8.
The reason for "powernow-k8 - out of sync" errors is because the cpufreq driver is not aware [or has the wrong idea] about which CPUs are tied together, because cpu_core_id and phy_proc_id data is wrong.
Now this is fairly harmless as Mark mentioned, but only on single socket Dual Core systems.
On a multi-socket multi-core system, it will result in something like: (2 dual-core Opterons)
cpu0: drwxr-xr-x 2 root root 0 Nov 3 09:51 cpufreq
cpu1: drwxr-xr-x 2 root root 0 Nov 3 09:51 cpufreq
cpu2: lrwxrwxrwx 1 root root 0 Nov 3 09:51 cpufreq -> ../../../../devices/system/cpu/cpu1/cpufreq
cpu3: lrwxrwxrwx 1 root root 0 Nov 3 09:51 cpufreq -> ../../../../devices/system/cpu/cpu1/cpufreq
In this configuration, the second processors will never be able to be managed by a governor.
I was wondering if anyone has already tested Andi's patch, if it successfully solves this problem, and if the patch has made it into the git yet.
Thanks,
-Jacob Shin AMD, Inc.
On cpufreq-bounces@lists.linux.org.uk wrote: >>> You'll get that message on an Athlon X2 if you're using an >>> old version of the driver that doesn't fully support >>> dual core or if your part is being reported to Linux as 2 single core parts. >>> >>> Neither of those should be happening with the 2.6.15.1 kernel. >> >> OK, seems we've really found a bug then. > > Yes, but it's a BIOS bug. > >>> Could you send me the results of `dmesg | grep powern` immediately >>> after boot? >> >> Sure: >> # dmesg|grep powern >> powernow-k8: Found 2 AMD Athlon 64 / Opteron processors (version 1.50.4) >> powernow-k8: 0 : fid 0xc (2000 MHz), vid 0x8 (1350 mV) >> powernow-k8: 1 : fid 0xa (1800 MHz), vid 0xa (1300 mV) >> powernow-k8: 2 : fid 0x2 (1000 MHz), vid 0x12 (1100 mV) >> powernow-k8: 0 : fid 0xc (2000 MHz), vid 0x8 (1350 mV) >> powernow-k8: 1 : fid 0xa (1800 MHz), vid 0xa (1300 mV) >> powernow-k8: 2 : fid 0x2 (1000 MHz), vid 0x12 (1100 mV) > > You're using a driver that supports dual-core, but the BIOS > is reporting the two cores as two separate processors. > They've probably got the APICIDs misconfigured. > > I've reported it to FSC and I advise you to do the same. > >> powernow-k8: error - out of sync, fix 0xc 0x2, vid 0x8 0x12 >> powernow-k8: error - out of sync, fix 0x2 0xa, vid 0x12 0xa >> powernow-k8: error - out of sync, fix 0xa 0xc, vid 0xa 0x8 >> powernow-k8: error - out of sync, fix 0xc 0x2, vid 0x8 0x12 >> powernow-k8: error - out of sync, fix 0x2 0xc, vid 0x12 0x8 >> powernow-k8: error - out of sync, fix 0xc 0x2, vid 0x8 0x12 > > These messages are mostly harmless, by the way, but some > people have seen system instability. I would enable > pmtimer support as your clock source, but that's advisable > when running a single dual-core anyway. > > -Mark Langsdorf > AMD, Inc. > > > _______________________________________________ > Cpufreq mailing list > Cpufreq@lists.linux.org.uk > http://lists.linux.org.uk/mailman/listinfo/cpufreq
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |