From: Anthony Liguori <aliguori@us.ibm.com>
To: kvm-ia64@vger.kernel.org
Subject: Re: [RFC PATCH 0/3] Avoid soft lockup message when KVM is stopped
Date: Thu, 04 Aug 2011 18:46:42 +0000 [thread overview]
Message-ID: <4E3AE912.7050402@us.ibm.com> (raw)
In-Reply-To: <1312381501-27746-1-git-send-email-emunson@mgebm.net>
On 08/04/2011 03:37 AM, Dor Laor wrote:
> 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
At least in the current steal time implementation, there are numerous
cases where steal time is not accounted but you'd hit a soft lockup.
Pausing an idle guest via (qemu) stop is an example. Likewise, a guest
that is descheduled while idle but then not scheduled for prolonged
periods of time would also not be accounted as steal time.
Regards,
Anthony Liguori
prev parent reply other threads:[~2011-08-04 18:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-03 14:24 [RFC PATCH 0/3] Avoid soft lockup message when KVM is stopped by host Eric B Munson
2011-08-04 8:37 ` [RFC PATCH 0/3] Avoid soft lockup message when KVM is stopped Dor Laor
2011-08-04 16:29 ` [RFC PATCH 0/3] Avoid soft lockup message when KVM is stopped by Marcelo Tosatti
2011-08-04 18:46 ` Anthony Liguori [this message]
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=4E3AE912.7050402@us.ibm.com \
--to=aliguori@us.ibm.com \
--cc=kvm-ia64@vger.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 read-only IMAP folder(s) and NNTP newsgroup(s).