From: Keir Fraser <keir.xen@gmail.com>
To: Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
xen-devel@lists.xensource.com
Cc: Ian Jackson <Ian.Jackson@eu.citrix.com>,
Ian Campbell <Ian.Campbell@citrix.com>
Subject: Re: default timer_mode in xen and in libxl
Date: Thu, 25 Apr 2013 18:25:23 +0100 [thread overview]
Message-ID: <CD9F2593.50A40%keir.xen@gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1304251810470.4180@kaball.uk.xensource.com>
On 25/04/2013 18:13, "Stefano Stabellini" <stefano.stabellini@eu.citrix.com>
wrote:
> Hi all,
> I have just noticed that the timer mode default in libxl is not the
> default in Xen.
> The Xen default is HVMPTM_delay_for_missed_ticks, while libxl by
> default sets it to LIBXL_TIMER_MODE_NO_DELAY_FOR_MISSED_TICKS that
> obviously is HVMPTM_no_delay_for_missed_ticks.
>
> Is there a reason for this?
> If so, should we change the defalt in Xen too?
Default in Xen is the original mode before multiple modes were supported. We
kept that as default for old/other toolstacks, to avoid surprising change in
behaviour (e.g., when they restore old saved guests).
Default in libxl is the sane one for newly-created guests. Hardly any guests
care about or even want time to be delayed until timer interrupts are fired
off.
-- Keir
> commit 2d058a444a1fa71ec47a673d08c2e74790ae67fb
> Author: Ian Campbell <ian.campbell@citrix.com>
> Date: Thu Mar 1 12:26:13 2012 +0000
>
> libxl: use an explicit LIBXL_TIMER_MODE_DEFAULT value
>
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2013-04-25 17:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-25 17:13 default timer_mode in xen and in libxl Stefano Stabellini
2013-04-25 17:25 ` Keir Fraser [this message]
2013-04-26 8:10 ` Ian Campbell
2013-04-26 9:59 ` Stefano Stabellini
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