WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] Re: [Patch] Enable "sysrq c" handler for domU coredump

To: Akio Takebe <takebe_akio@xxxxxxxxxxxxxx>
Subject: [Xen-devel] Re: [Patch] Enable "sysrq c" handler for domU coredump
From: Horms <horms@xxxxxxxxxxxx>
Date: Tue, 1 Aug 2006 18:26:23 +0900
Cc: Muli Ben-Yehuda <muli@xxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Kouya Shimura <kouya@xxxxxxxxxxxxxx>
Delivery-date: Wed, 02 Aug 2006 01:52:19 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <50C6B549C9FCF3takebe_akio@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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20060801064805.GA14886@xxxxxxxxxxxx> <50C6B549C9FCF3takebe_akio@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.12-2006-07-14
On Tue, Aug 01, 2006 at 06:06:35PM +0900, Akio Takebe wrote:
> >On Tue, Aug 01, 2006 at 01:39:23PM +0900, Akio Takebe wrote:
> >> Hi, Horms
> >> 
> >> >
> >> >That seems fine to me. Though there was some resistance to a
> >> >patch I sent which adds a panic option to xen-console, which
> >> >is the hypervisor equivalent of sysrq.
> >> >
> >> This patch focus only manually dumping domU's core.
> >> How can I use the panic option of xen-console?
> >> I thought your patch to panic xen.
> >> Can I dump domU's core with the option?
> >
> >Sorry, I was not clear.
> >
> >Yes, my patch is to panic (or more recently cause a crash dump) 
> >in the hypervisor. It does not give any special behaviour to
> >the domains.
> >
> >What I meant was, that the idea of adding a panic to domU's sysrq
> >is similar to my idea of adding panic to the xen console. And I was
> >asked to change this patch to make it trigger a kdump directly,
> >rather than a panic.
> >
> >I think that your sysrq patch and my xen-console panic patches
> >are related, and I wanted to bring that into the discussion.
> >
> Horms, what you said, that I had better call crash_kexec() 
> than panic() on dom0?

Thats not what I was thinking, but now you mention it...

> If so, I agree for dom0 directly calling crash_kexec().
> But because now vmlinux is used as both dom0 and domU,
> we cannot use ifdef for separateing dom0 and domU.
> So I call panic() on both dom0 and domU.
> I also think option like a unknown_nmi_panic is useful 
> and necessary for dump and debug.
> 
> Everyone, how about the below?
> 1. If crash_kexec() is called on dom0, dom0 do hypercall
>    then xen do kexec/kdump
> 2. If crash_kexec() is called on domU, domU do hypercall
>    then xen do panic_domain(), and domU's core is dumped.

I think that is a good idea, because it gives consistent behaviour
for dom0 and domU, even though the mechanics differ. Though if
kexec for domU is merged, things may change at that time.

> So I don't need to modify linux code. :-)

:-)

> Or How about "xm dump"?
> (Probably I use panic_domain() by hypercall.
> This way can probably dump HVM domain.)

That is also a good idea, though it could be done as well,
rather than instead of your crash_kexec() -> hypercall idea.

> I think we need to have the way manually to dump domU, or Xen.
> (Because for the time when domU or Xen don't panic 
> and spinloop and so on) 

That is a good point, which makes your xm dump idea somewhat
more attactive than the crash_kexec() -> hypercall idea.
But I still think they both make sense.

-- 
Horms
  H: http://www.vergenet.net/~horms/
  W: http://www.valinux.co.jp/en/


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

<Prev in Thread] Current Thread [Next in Thread>