From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dor Laor <dlaor@redhat.com>
Subject: Re: [RFC PATCH 0/3] Avoid soft lockup message when KVM is stopped
 by host
Date: Thu, 04 Aug 2011 11:37:12 +0300
Message-ID: <4E3A5A38.9080406@redhat.com>
References: <1312381501-27746-1-git-send-email-emunson@mgebm.net>
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Cc: kvm@vger.kernel.org, kvm-ia64@vger.kernel.org,
	kvm-ppc@vger.kernel.org, avi@redhat.com, riel@redhat.com,
	glommer@redhat.com, linux-kernel@vger.kernel.org,
	aliguori@us.ibm.com, raharper@us.ibm.com,
	Glauber Costa <glommer@gmail.com>
To: Eric B Munson <emunson@mgebm.net>
Return-path: <kvm-ppc-owner@vger.kernel.org>
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On 08/03/2011 05:24 PM, Eric B Munson wrote:
> This set is just a rough first pass at avoiding soft lockup warnings when a host
> pauses the execution of a guest.  A flag is set by the host in the shared page
> used for the pvclock when the host goes to stop the guest.  When the guest
> resumes and detects a soft lockup, this flag is checked and cleared and the soft
> lockup message is skipped.

While this will cover the case were the host stops a guest, there will 
be other plain cases where the host is just over committed and will 
cause a softlockup false positive on the guest.

Softlockup should use stolen time that makes use of the guest running 
info would cover both cases

>
> This currently breaks the build for non-x86 architectures but part of what I am
> looking for here is how to go about adding the function stubs for everything
> else.
>
> Eric B Munson (3):
>    Add flag to indicate that a vm was stopped by the host
>    Add functions to check if the host has stopped the vm
>    Add check for suspended vm in softlockup detector
>
>   arch/x86/include/asm/pvclock-abi.h |    1 +
>   arch/x86/include/asm/pvclock.h     |    3 +++
>   arch/x86/kernel/kvmclock.c         |   12 ++++++++++++
>   kernel/watchdog.c                  |   11 +++++++++++
>   4 files changed, 27 insertions(+), 0 deletions(-)
>