Clock too fast on SMP Linux

From Finninday
Jump to: navigation, search

Tuesday, December 27th, 2005

I’m having trouble with the clock on the AMD64 SMP machine running too fast. This link from Ubuntu forums was helpful, but the clock still runs fast. Just not as fast as before. It guided me through making changes to the boot options in /boot/grub/menu.lst, specifically adding “no_timer_check”.

Another forum entry recommends booting with the option “notsc” or applying a kernel patch for this known bug. It was committed to the 2.6.14 tree on Sept 28, 2005.

Here is the full bug report stating that it was fixed in kernel

My current kernel is 2.6.12-10-amd64-k8-smp #1 SMP Fri Nov 18 12:20:27 UTC 2005 x86_64 GNU/Linux

Now I need to learn enough about apt to figure out what packages have been recently updated. Maybe I got a kernel update and haven’t rebooted to activate it yet. What I’d really like is a command to show the last 10 installed or upgraded packages.

Tuesday, January 10th, 2006

I took the plunge and built a new kernel. I followed most of the directions from this site. I didn’t trust the patch for improved performance though. Who knows what that does? So I just built the stock kernel. The cruel irony was that I couldn’t time the compile of the kernel because my clock was running too fast. I’ll have to try another kernel compile sometime now that the clock is fixed.

The NVIDIA kernel module needed to be rebuilt, so I just went through the procedure with the latest driver from their site. It is amazing how well their tool works in such an error-fraught domain.

Oh, and while in the kernel configuration, I poked around looking for a switch to enable >2GB of RAM, but didn’t find it. Huh.

But at least the server build can move forward again. Soon enough my Linux Cookbook will arrive and I’ll see if things have really changed that much since I did this last. It has a chapter on SMTP Auth and Postfix config. I could use one of those… it was so painful doing it last time. There were a few other bits that looked like it would be worthwhile to get a little broader context. I’m betting it will end up being pretty useful in this process.