On Wed, Dec 13, 2017 at 10:57:55AM +0100, Greg KH wrote:
On Wed, Dec 13, 2017 at 11:45:20AM +0200, Dan Aloni wrote:
git cherry-pick -x 16588f659257 # x86/tsc: Annotate printouts as firmware bug git cherry-pick -x 8c9b9d87b855 # x86/tsc: Limit the adjust value further
There's a conflict only in a one small place in the first few patches.
[..] That's a lot of changes to be backported. I'm _really_ hesitant to do this, unless the maintainer of the code agrees it is ok...
I guessed so, that's why I probed. Otherwise I would have just sent out patches.
These changes percisely fix an issue I am having with a relatively new 8-core Intel(R) Core(TM) i7-7820X with an updated ASUS BIOS (December 2017).
Under v4.9.68, the kernel fallbacks on the chosen clocksource to HPET which just doesn't work - there is over a 200ms time drift that does not go away even after repeated ntpdate sync attempts.
For further testing I've posted a branch for these changes here:
https://github.com/kernelim/linux tsc-fix-for-4.9.xWhy not just use 4.14 instead? That's much easier than trying to use an old kernel like 4.9, right?
Yes, however the milage of 4.9.x seems more appealing somewhat.
Why? 4.14 should be much better, it's newer, has more hardware support, more bugs fixed, and more new things left to debug :)
I always enjoy debugging :)
I'll give 4.14.x a try mostly to see whether it solves hard locks that I've seen with 4.13.x (all Fedora-based stable kernels) on three of my machines -- an unrelated issue, and the main reason why I gave one of the LTS branches a try.
You really should report that. Without that, odds are it will not be fixed.
I am still collecting data, but these systems are being used rather constantly so the downtime is problematic. It's a) a rather new workstation, 2) an Intel Nuc, and 3) An old Lenovo Carbon X1 Gen 3.
I should have also used a vanilla build because I know that on LKML it has preference over the Fedora-based patchset. I will try to see if it produces on 4.14.x and perhaps kdump will be able to capture it this time.