From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ky Srinivasan" Subject: Re: Re: [PATCH] SMP dom0 boot fix Date: Fri, 28 Oct 2005 11:27:10 -0600 Message-ID: <4362272C.E57C.0030.0@novell.com> References: <5916684ed3d62883c5aa18c358b24b21@cl.cam.ac.uk> <20051028145930.GL22394@us.ibm.com> <537fa3b9fb43e4581f282edb2ced8627@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <537fa3b9fb43e4581f282edb2ced8627@cl.cam.ac.uk> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: Ian Pratt , xen-devel , Ryan Harper List-Id: xen-devel@lists.xenproject.org Thanks Kier. With this fix applied, I am able to boot SMP dom0. The box I am testing on is x86_64 machine with two hardware threads. However, if I turn on SMT in the Linux configuration, the kernel takes a fault in early startup (a NULL pointer reference at find_busiest_group +144). It appears that the sched domain hierarchy is not correctly set up here. Looking at the new smpboot.c, is turning on SMT support no longer valid? K. Y >>> Keir Fraser 10/28/05 11:45 am >>> On 28 Oct 2005, at 16:15, Keir Fraser wrote: > > On 28 Oct 2005, at 15:59, Ryan Harper wrote: > >> At this point send_IPI_allbutself() has been invoked and the system >> just sits and waits on CPU1 to run the function. But, CPU1's >> evtchn_upcall_mask was set (1), so I'm guessing the pending interrupt >> is never acknowledged. > > Okay, the good news is that's the same bug I was able to repro last > week. Turns out that CPU1's upcall mask is getting weirdly set under > its feet. Since it's waiting on the big kernel lock, which is held by > CPU0, which is waiting for acknowledgement of an interrupt in CPU1, we > have a deadlock. > > Given the problem is in that one changeset, this can't be hard to > track down now. Now fixed in our staging tree. sizeof_vcpu_shift in arch/xen/x86_64/xen_entry.S should be 4, not 3. -- Keir _______________________________________________ Xen- devel mailing list Xen- devel@lists.xensource.com http://lists.xensource.com/xen- devel