From: Thomas Gleixner <tglx@linutronix.de>
To: Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>,
Bruce Schlobohm <bruce.schlobohm@intel.com>,
Roland Scheidegger <rscheidegger_lists@hispeed.ch>,
Kevin Stanton <kevin.b.stanton@intel.com>,
Allen Hung <allen_hung@dell.com>,
stable@vger.kernel.org
Subject: Re: [patch 2/2] x86/tsc: Force TSC_ADJUST register to value >= zero
Date: Fri, 16 Dec 2016 12:53:24 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1612161252110.3470@nanos> (raw)
In-Reply-To: <20161216115254.GA18902@gmail.com>
On Fri, 16 Dec 2016, Ingo Molnar wrote:
> * Thomas Gleixner <tglx@linutronix.de> wrote:
>
> > We have two options:
> >
> > 1) Disable TSC deadline timer by default and force users with sane machines
> > to enable it on the kernel command line.
> >
> > Upside: Very small patch
> >
> > Downside: Degrades existing setups on sane machines, keeps TSC unusable
> > on affected machines. We have no idea what other hidden side
> > effects the TSC_ADJUST tinkering has. If there are any, they
> > ain't be nice ones.
> >
> > 2) Push the whole TSC_ADJUST sanitizing machinery into stable
> >
> > Upside: Does not affect sane machines and gives a benefit to users of
> > affected machines
> >
> > Downside: Rather large patch, but not that risky either. Needs a few
> > eyes and good test coverage though
> >
> > Thoughts?
>
> I'd go for #2, because #1 is essentially turning it off for almost everyone.
>
> We can still do #1 and push it back to -stable as well if #2 fails.
>
> But I'd suggest we delay the stable backporting until it's been upstream a bit.
I agree. None of these patches is tagged stable. I just wanted to mention
it so it can be discussed before distros/stable users are swamped with
failure reports.
Thanks,
tglx
next prev parent reply other threads:[~2016-12-16 11:56 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-13 13:14 [patch 0/2] tsc/adjust: Cure suspend/resume issues and prevent TSC deadline timer irq storm Thomas Gleixner
2016-12-13 13:14 ` [patch 1/2] x86/tsc: Validate TSC_ADJUST after resume Thomas Gleixner
2016-12-13 13:22 ` Peter Zijlstra
2016-12-13 13:23 ` Thomas Gleixner
2016-12-15 10:52 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2016-12-13 13:14 ` [patch 2/2] x86/tsc: Force TSC_ADJUST register to value >= zero Thomas Gleixner
2016-12-13 13:43 ` Peter Zijlstra
2016-12-13 15:49 ` Thomas Gleixner
2016-12-15 10:53 ` [tip:x86/timers] " tip-bot for Thomas Gleixner
2016-12-16 11:46 ` [patch 2/2] " Thomas Gleixner
2016-12-16 11:52 ` Ingo Molnar
2016-12-16 11:53 ` Thomas Gleixner [this message]
2016-12-16 13:33 ` Thomas Gleixner
2016-12-13 16:34 ` [patch 0/2] tsc/adjust: Cure suspend/resume issues and prevent TSC deadline timer irq storm Roland Scheidegger
2016-12-13 16:46 ` Thomas Gleixner
2016-12-14 1:36 ` Roland Scheidegger
2016-12-14 7:31 ` Thomas Gleixner
2016-12-14 20:59 ` Thomas Gleixner
2016-12-14 21:40 ` Thomas Gleixner
2016-12-14 22:54 ` Roland Scheidegger
2016-12-15 9:31 ` Thomas Gleixner
2017-01-26 23:40 ` Stanton, Kevin B
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=alpine.DEB.2.20.1612161252110.3470@nanos \
--to=tglx@linutronix.de \
--cc=allen_hung@dell.com \
--cc=bp@alien8.de \
--cc=bruce.schlobohm@intel.com \
--cc=kevin.b.stanton@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=rscheidegger_lists@hispeed.ch \
--cc=stable@vger.kernel.org \
--cc=x86@kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).