public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: Dan Aloni <dan@kernelim.com>
Cc: stable@vger.kernel.org,
	Linux Kernel List <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Bin Gao <bin.gao@linux.intel.com>
Subject: Re: TSC x86 fixes for LTS kernel 4.9.x
Date: Wed, 13 Dec 2017 10:03:35 +0100	[thread overview]
Message-ID: <20171213090335.GA5496@kroah.com> (raw)
In-Reply-To: <20171213083352.GA15356@gmail.com>

On Wed, Dec 13, 2017 at 10:33:52AM +0200, Dan Aloni wrote:
> Hi all,
> 
> I've tested the following changes, belonging to merge commit f7dd3b1734e,
> on top of 4.9.68 after a very easy backport from 4.10, and I think it
> may be worthwhile adding them to 4.9.x:
> 
>       x86/tsc: Limit the adjust value further
>       x86/tsc: Annotate printouts as firmware bug
>       x86/tsc: Force TSC_ADJUST register to value >= zero
>       x86/tsc: Validate TSC_ADJUST after resume
>       x86/tsc: Validate cpumask pointer before accessing it
>       x86/tsc: Fix broken CONFIG_X86_TSC=n build
>       x86/tsc: Try to adjust TSC if sync test fails
>       x86/tsc: Prepare warp test for TSC adjustment
>       x86/tsc: Move sync cleanup to a safe place
>       x86/tsc: Sync test only for the first cpu in a package
>       x86/tsc: Verify TSC_ADJUST from idle
>       x86/tsc: Store and check TSC ADJUST MSR
>       x86/tsc: Detect random warps
>       x86/tsc: Use X86_FEATURE_TSC_ADJUST in detect_art()
>       x86/tsc: Finalize the split of the TSC_RELIABLE flag
>       x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs
>       x86/tsc: Mark Intel ATOM_GOLDMONT TSC reliable
>       x86/tsc: Mark TSC frequency determined by CPUID as known
>       x86/tsc: Add X86_FEATURE_TSC_KNOWN_FREQ flag

I need git commit ids to be able to do anything :)

> 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.x

Why not just use 4.14 instead?  That's much easier than trying to use an
old kernel like 4.9, right?

thanks,

greg k-h

  reply	other threads:[~2017-12-13  9:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-12-13  8:33 TSC x86 fixes for LTS kernel 4.9.x Dan Aloni
2017-12-13  9:03 ` Greg KH [this message]
2017-12-13  9:45   ` Dan Aloni
2017-12-13  9:57     ` Greg KH
2017-12-13 10:14       ` Dan Aloni
2017-12-13 15:07       ` Thomas Gleixner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20171213090335.GA5496@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=bin.gao@linux.intel.com \
    --cc=dan@kernelim.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox