[Xen-devel] Re: IRQs, move_in_progress, -EBUSY &c

To:	George Dunlap <George.Dunlap@xxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Jeremy Fitzhardinge <jeremy@xxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Subject:	[Xen-devel] Re: IRQs, move_in_progress, -EBUSY &c
From:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date:	Wed, 11 Aug 2010 16:04:40 +0100
Cc:
Delivery-date:	Wed, 11 Aug 2010 08:07:05 -0700
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to:	<AANLkTin2Q9pH+v=Nm=T-R_sgajrdxKy5nj+_5Ja+Wb6Y@xxxxxxxxxxxxxx>
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index:	Acs5ZVZM0PNKzfRMRZC05S/nVlusCQAAS8/n
Thread-topic:	IRQs, move_in_progress, -EBUSY &c
User-agent:	Microsoft-Entourage/12.24.0.100205

On 11/08/2010 15:56, "George Dunlap" <George.Dunlap@xxxxxxxxxxxxx> wrote:

> However, it seems that moving IRQs is not handled properly.  Either
> the pvops kernel should retry if it gets an -EBUSY, or the hypercall
> should not fail, but wait until it can return success.

Move_in_progress is a private hypervisor implementation detail. We shouldn't
make it visible to the guest via EBUSY. Worst case we should be turning the
retry into a hypercall continuation. Even better if we don't need to make
the IRQ bind request wait at all... Not sure why that needs to happen at
all.

 -- Keir

> I discovered all this by adding debug statements to the IRQ path; the
> patch is attached, if anyone else wants to use it.
> 
>  -George

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

WARNING - OLD ARCHIVES

xen-devel

[Xen-devel] Re: IRQs, move_in_progress, -EBUSY &c