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From: hiro <23hiro@gmail.com>
To: 9front@9front.org
Subject: Re: [9front] qemu clock/timer issue
Date: Sat, 5 Feb 2022 18:04:16 +0100	[thread overview]
Message-ID: <CAFSF3XMXafw5Fvugd8ZFMvGvCrise-_XznyKVj=cUdSpofqS-A@mail.gmail.com> (raw)
In-Reply-To: <CAGw6cBvo+bA9BCOdXtM8O6vezod1szmVgKj0g-YnNYagf5++hw@mail.gmail.com>

do you have timesync running twice? check in ps output.

On 2/5/22, Michael Forney <mforney@mforney.org> wrote:
> I was recently running 9front in a VM on linux (qemu, with
> -enable-kvm), and noticed several weird timing/clock issues. The date
> command gives wildly varying results +- 1 minute:
>
> cpu% date
> Fri Feb  4 17:39:23 PST 2022
> cpu% date
> Fri Feb  4 17:39:12 PST 2022
> cpu% date
> Fri Feb  4 17:40:19 PST 2022
> cpu% date
> Fri Feb  4 17:39:18 PST 2022
>
> `sleep 1` exits pretty much instantly, stats moves through the entire
> width in a second or two, and clicking in scrollbars starts repeating
> immediately.
>
> I notice the following messages in my dmesg:
> kvm: vcpu 3: requested 38141 ns lapic timer period limited to 200000 ns
> kvm: vcpu 1: requested 9449 ns lapic timer period limited to 200000 ns
> kvm: vcpu 2: requested 51204 ns lapic timer period limited to 200000 ns
> kvm: vcpu 0: requested 74421 ns lapic timer period limited to 200000 ns
>
> I don't remember this problem last time I ran 9front in qemu (around a
> year ago), so I looked through commit history and found one commit
> that seemed like it might be related:
> http://git.9front.org/plan9front/plan9front/a05bab362f66ddd6fa65f2e7cda9eaaa0217ec08/commit.html
>
> To check, I tried setting *nohpet=1 in my plan9.ini, which *seems* to
> have solved the problem, though I still see those same messages in
> dmesg on the linux host (but now the requested lapic timer period is
> always around 100000 ns or greater).
>
> Anyone know what's going on here?
>

  reply	other threads:[~2022-02-05 17:42 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-05  2:04 Michael Forney
2022-02-05 17:04 ` hiro [this message]
2022-02-05 18:14 ` Nick Owens
2022-02-18  3:25   ` Michael Forney
2022-02-21 22:35     ` cinap_lenrek

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