From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] Allocate vmcs pages when system booting Date: Thu, 12 Nov 2009 15:04:02 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Jiang, Yunhong" , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 12/11/2009 14:58, "Jiang, Yunhong" wrote: >> Can you try this alternative fix please? > > Yes, spin_debug_disable() is the first idea come into my mind, I change my > mind because the spin_debug is a global variable. disable spin_debug() before > start_secondary means maybe we can't catch error happens at that window, so I > choose this method. Previously I thought high-end system support cpu hotplug > may not care about the 64 pages :$ CONFIG_HOTPLUG_CPU is not a user-accessible build option. In fact manually disabling it in config.h resulted in a broken build, and now I basically stripped out the non-HOTPLUG_CPU code (in c/s 20431). So this would be an overhead for absolutely everyone. > Or you assume this window is quite small, and we can assume safely if a error > happening at this window, it will happen in other timeslot in the end, > sepecially this function itself don't need the check? Exactly. The spinlock debug checking can be best effort. I did think about allowing the checks to be disabled per-cpu, but I don't think it's worth it. I will check in my suggested fix, then. -- Keir