Broken /proc/stat

[linkfanel]

Using linux 2.6.39 and grsecurity-2.2.2-2.6.39-201105251736.patch, CPU usage times reported in /proc/stat seem a bit off... A sample line:

cpu 22602 0 0 0 0 209909 0 0 0 0

top reports 100% in hi when the system should be idle. That's on i386; it seems to work fine on my 64 bit machine.

[spender]

I'm not able to reproduce this on either i386 or amd64. Have you tried a vanilla kernel?

-Brad

[linkfanel]

Yes, it works fine with a vanilla kernel. Here's my .config: http://www.linkfanel.net/stuff/config-2.6.39-grsec

[spender]

Can you link to the vanilla config as well? Enabling grsecurity toggles some vanilla kernel config settings, so I'd want to make sure it wasn't due to one of those. I'll give it a look tonight. In the meantime, you could also try a binary search to find the problematic option if grsec is at fault.

-Brad

[linkfanel]

Vanilla config: http://www.linkfanel.net/stuff/config-2.6.39
The problem happens even with grsecurity disabled altogether.

[spender]

Can you test a kernel with just the latest PaX patch applied?

-Brad

[linkfanel]

I tested a kernel with just the PaX patch, and PaX disabled, but the problem is still there.

[PaX Team]

I tested a kernel with just the PaX patch, and PaX disabled, but the problem is still there.

can you disable CGROUPS and tell me if you still see the problem? (mind you, stat/top are fine here even with the CGROUPS options enabled) also, does anyone else have this problem?

[linkfanel]

Yes, I disabled CGROUPS and the problem is still there.

[PaX Team]

the latest patches should fix the issue.

[linkfanel]

Yes, this issue is fixed. Thanks!