Bug 212268 – ~sys-kernel/gentoo-sources-2.6.23 rounded ping problem

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description jergendutch 2008-03-04 12:11:34 UTC]

I have two boxes, on one box I get my ping times rounded to the nearest 4 ms, so I often get ping times of 4.00 ms or 0.000 ms.
On the other box, which is almost identical, I get normal (correct) ping times, e.g. 3.16 ms, 1.41 ms

From a hardware perspective, the box with the bad ping times has an extra processor and a bit more ram.

From a configuration perspective, both boxes have the same .config file and no differing sysctl settings.
CONFIG_HZ_250=y and CONFIG_HZ=250 are set (1000/4=250 so might be useful)

The problem occurs on 2.6.23-gentoo-r9, 2.6.23-gentoo-r8.
Downgrading to the previously used kernel, linux-2.6.19-gentoo-r5, resolves the problem.

Reproducible: Always

[Comment 1 Mike Pagano 2008-03-06 01:24:21 UTC]

What happens with 2.6.24-r3? If that also fails, can you try the latest development kernel which is vanilla 2.6.25-rc4 right now?

[Comment 2 jergendutch 2008-03-06 10:04:37 UTC]

This is on a production box, and I can't reproduce it on other hardware.
I can't install a development kernel on it, but I can certainly install the next production kernel when it comes out.

[Comment 3 Daniel Drake (RETIRED) 2008-03-11 16:52:48 UTC]

please post .configs from both systems
i suspect one system has NO_HZ or hrtimer enabled and the other doesn't

[Comment 4 jergendutch 2008-03-12 07:48:45 UTC]

Both servers have identical output from /proc/config.gz

[Comment 5 Daniel Drake (RETIRED) 2008-03-12 09:55:16 UTC]

please post the config anyway

[Comment 6 jergendutch 2008-03-17 08:56:03 UTC]

Problem gone in 2.6.24-r3

[Comment 7 Daniel Drake (RETIRED) 2008-03-17 09:43:22 UTC]

Great, thanks for letting us know.