From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Jeff Dike <jdike@addtoit.com>
Cc: Nix <nix@esperi.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org,
user-mode-linux-devel@lists.sourceforge.net, dhazelton@enter.net
Subject: Re: [uml-devel] [PATCH 1/6] UML - Deal with host time going backwards
Date: Wed, 04 Jun 2008 21:05:11 +0100 [thread overview]
Message-ID: <4846F577.10603@goop.org> (raw)
In-Reply-To: <20080604193715.GA11943@c2.user-mode-linux.org>
Jeff Dike wrote:
> On Wed, Jun 04, 2008 at 03:31:58PM +0100, Jeremy Fitzhardinge wrote:
>
>> Shouldn't UML use a monotonic host clock for guest timekeeping?
>>
>
> Indeed, Eric pointed out the posix timers, which I had forgotten
> about. On the face of it, a monotonic timer should do the trick, but
> it's not obvious how to get it to behave like a monotonic
> gettimeofday...
You can either read the monotonic clock directly, or use it as a time
source for a monotonic timer. clock_gettime(CLOCK_MONOTONIC, &ts) will
return the time in ns, and you can just feed that directly into the
guest as a clocksource.
J
-------------------------------------------------------------------------
Check out the new SourceForge.net Marketplace.
It's the best place to buy or sell services for
just about anything Open Source.
http://sourceforge.net/services/buy/index.php
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
WARNING: multiple messages have this Message-ID (diff)
From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Jeff Dike <jdike@addtoit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Nix <nix@esperi.org.uk>,
dhazelton@enter.net, linux-kernel@vger.kernel.org,
user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [PATCH 1/6] UML - Deal with host time going backwards
Date: Wed, 04 Jun 2008 21:05:11 +0100 [thread overview]
Message-ID: <4846F577.10603@goop.org> (raw)
In-Reply-To: <20080604193715.GA11943@c2.user-mode-linux.org>
Jeff Dike wrote:
> On Wed, Jun 04, 2008 at 03:31:58PM +0100, Jeremy Fitzhardinge wrote:
>
>> Shouldn't UML use a monotonic host clock for guest timekeeping?
>>
>
> Indeed, Eric pointed out the posix timers, which I had forgotten
> about. On the face of it, a monotonic timer should do the trick, but
> it's not obvious how to get it to behave like a monotonic
> gettimeofday...
You can either read the monotonic clock directly, or use it as a time
source for a monotonic timer. clock_gettime(CLOCK_MONOTONIC, &ts) will
return the time in ns, and you can just feed that directly into the
guest as a clocksource.
J
next prev parent reply other threads:[~2008-06-04 20:05 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-03 19:02 [uml-devel] [PATCH 1/6] UML - Deal with host time going backwards Jeff Dike
2008-06-03 19:02 ` Jeff Dike
2008-06-03 19:32 ` [uml-devel] " Andrew Morton
2008-06-03 19:32 ` Andrew Morton
2008-06-03 19:43 ` [uml-devel] " Daniel Hazelton
2008-06-03 19:43 ` Daniel Hazelton
2008-06-03 19:52 ` [uml-devel] " Nix
2008-06-03 19:52 ` Nix
2008-06-03 20:07 ` [uml-devel] " Andrew Morton
2008-06-03 20:07 ` Andrew Morton
2008-06-03 20:37 ` [uml-devel] " Daniel Hazelton
2008-06-03 20:37 ` Daniel Hazelton
2008-06-03 21:00 ` [uml-devel] " Jeff Dike
2008-06-03 21:00 ` Jeff Dike
2008-06-04 1:50 ` [uml-devel] " Eric W. Biederman
2008-06-04 1:50 ` Eric W. Biederman
2008-06-04 3:15 ` [uml-devel] " Jeff Dike
2008-06-04 3:15 ` Jeff Dike
2008-06-04 5:12 ` [uml-devel] " Daniel Hazelton
2008-06-04 5:12 ` Daniel Hazelton
2008-06-04 14:31 ` [uml-devel] " Jeremy Fitzhardinge
2008-06-04 14:31 ` Jeremy Fitzhardinge
2008-06-04 19:37 ` [uml-devel] " Jeff Dike
2008-06-04 19:37 ` Jeff Dike
2008-06-04 20:05 ` Jeremy Fitzhardinge [this message]
2008-06-04 20:05 ` Jeremy Fitzhardinge
2008-06-05 15:30 ` [uml-devel] " Jeff Dike
2008-06-05 15:30 ` Jeff Dike
2008-06-05 18:14 ` [uml-devel] " Nix
2008-06-05 18:14 ` Nix
2008-06-05 19:47 ` [uml-devel] " Jeff Dike
2008-06-05 19:47 ` Jeff Dike
2008-06-05 21:41 ` [uml-devel] " Nix
2008-06-05 21:41 ` Nix
2008-06-05 18:19 ` [uml-devel] " Nix
2008-06-05 18:19 ` Nix
-- strict thread matches above, loose matches on Subject: below --
2008-06-03 19:59 [uml-devel] " devzero
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=4846F577.10603@goop.org \
--to=jeremy@goop.org \
--cc=akpm@linux-foundation.org \
--cc=dhazelton@enter.net \
--cc=jdike@addtoit.com \
--cc=linux-kernel@vger.kernel.org \
--cc=nix@esperi.org.uk \
--cc=user-mode-linux-devel@lists.sourceforge.net \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.