From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH 4 of 6 v2] xen: tracing: report where a VCPU wakes up Date: Fri, 14 Dec 2012 19:57:21 +0000 Message-ID: <50CB84A1.1060205@eu.citrix.com> References: <7a199dea34425e890b31.1355280774@Solace> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <7a199dea34425e890b31.1355280774@Solace> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli Cc: "xen-devel@lists.xensource.com" , "Keir (Xen.org)" , Ian Campbell List-Id: xen-devel@lists.xenproject.org On 12/12/12 02:52, Dario Faggioli wrote: > When looking at traces, it turns out to be useful to know where a > waking-up VCPU is being queued. Yes, that is always the CPU where > it ran last, but that information can well be lost in past trace > records! When you say "lost in past trace records", do you primarily mean that the records themselves have been lost (due to the per-cpu trace buffers filling up), or do you mean that it may be way way back and you don't want to go back and find it? If the latter, I think the best thing to do would be to just augment xenalyze to keep track of that information and print it when it sees the wake record. -George