| 2016-02-24 21:40:17 |
Andy Whitcroft |
bug |
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added bug |
| 2016-02-24 21:40:25 |
Andy Whitcroft |
linux (Ubuntu): status |
New |
In Progress |
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| 2016-02-24 21:40:28 |
Andy Whitcroft |
linux (Ubuntu): importance |
Undecided |
Medium |
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| 2016-02-24 21:40:29 |
Andy Whitcroft |
linux (Ubuntu): assignee |
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Andy Whitcroft (apw) |
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| 2016-02-25 13:51:50 |
Andy Whitcroft |
linux (Ubuntu): status |
In Progress |
Fix Committed |
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| 2016-02-28 17:23:14 |
Tim Gardner |
nominated for series |
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Ubuntu Xenial |
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| 2016-02-28 17:23:14 |
Tim Gardner |
bug task added |
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linux (Ubuntu Xenial) |
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| 2016-03-02 01:34:34 |
Launchpad Janitor |
branch linked |
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lp:ubuntu/trusty-proposed/linux-lts-xenial |
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| 2016-03-02 12:32:04 |
Launchpad Janitor |
linux (Ubuntu Xenial): status |
Fix Committed |
Fix Released |
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| 2016-03-21 21:27:10 |
dann frazier |
linux (Ubuntu Xenial): assignee |
Andy Whitcroft (apw) |
dann frazier (dannf) |
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| 2016-03-21 21:27:12 |
dann frazier |
linux (Ubuntu Xenial): status |
Fix Released |
Confirmed |
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| 2016-03-29 16:43:09 |
Launchpad Janitor |
linux (Ubuntu Xenial): status |
Confirmed |
Fix Released |
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| 2016-04-08 16:29:59 |
dann frazier |
linux (Ubuntu Xenial): status |
Fix Released |
Confirmed |
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| 2016-04-11 19:56:15 |
dann frazier |
linux (Ubuntu Xenial): status |
Confirmed |
In Progress |
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| 2016-04-11 22:19:36 |
dann frazier |
description |
This series from linux-next prevents guest hangs when ntpd is running
on the host.
The following changes since commit 736667efc11e42284c0572d8cc9a3aa4a1842b55:
i40e/i40evf: Bump i40e to 1.4.25 and i40evf to 1.4.15 (2016-02-19
16:22:01 -0700)
are available in the git repository at:
git://kernel.ubuntu.com/dannf/ubuntu-xenial.git hrtimer-C_M_R
for you to fetch changes up to 7dd9854d8674144013c3678bceba1b6a626db36d:
KVM: arm/arm64: timer: Switch to CLOCK_MONOTONIC_RAW (2016-02-22
13:13:18 -0700) |
SRU Justification:
Impact: KVM guests hang on arm64 host running ntpd
Fix: From linux-next:
commit 1c5631c73fc2261a5df64a72c155cb53dcdc0c45
Author: Marc Zyngier <marc.zyngier@arm.com>
Date: Wed Apr 6 09:37:22 2016 +0100
KVM: arm/arm64: Handle forward time correction gracefully
BugLink: http://bugs.launchpad.net/bugs/1549494
On a host that runs NTP, corrections can have a direct impact on
the background timer that we program on the behalf of a vcpu.
In particular, NTP performing a forward correction will result in
a timer expiring sooner than expected from a guest point of view.
Not a big deal, we kick the vcpu anyway.
But on wake-up, the vcpu thread is going to perform a check to
find out whether or not it should block. And at that point, the
timer check is going to say "timer has not expired yet, go back
to sleep". This results in the timer event being lost forever.
There are multiple ways to handle this. One would be record that
the timer has expired and let kvm_cpu_has_pending_timer return
true in that case, but that would be fairly invasive. Another is
to check for the "short sleep" condition in the hrtimer callback,
and restart the timer for the remaining time when the condition
is detected.
This patch implements the latter, with a bit of refactoring in
order to avoid too much code duplication.
Testcase:
A) Install ntp on the host (I'm using a 2 socket ThunderX)
B) Boot up a large VM (95 CPUs/4G memory)
C) Within the VM, rebuild the Ubuntu kernel package
If it doesn't hang - bug is gone. |
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| 2016-04-13 21:28:37 |
dann frazier |
linux (Ubuntu Xenial): status |
In Progress |
Fix Committed |
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| 2016-04-19 18:39:47 |
Launchpad Janitor |
linux (Ubuntu Xenial): status |
Fix Committed |
Fix Released |
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| 2016-04-19 18:39:47 |
Launchpad Janitor |
cve linked |
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2016-2847 |
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