From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 7/7] trace: Trace virtqueue operations Date: Tue, 25 May 2010 16:52:34 +0300 Message-ID: <4BFBD622.20100@redhat.com> References: <1274783056-14759-1-git-send-email-stefanha@linux.vnet.ibm.com> <1274783056-14759-8-git-send-email-stefanha@linux.vnet.ibm.com> <4BFBBCC3.2080905@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Stefan Hajnoczi , qemu-devel@nongnu.org, kvm@vger.kernel.org, Jan Kiszka , Prerna Saxena , Anthony Liguori To: Stefan Hajnoczi Return-path: Received: from mx1.redhat.com ([209.132.183.28]:24171 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756440Ab0EYNwm (ORCPT ); Tue, 25 May 2010 09:52:42 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 05/25/2010 04:27 PM, Stefan Hajnoczi wrote: > On Tue, May 25, 2010 at 1:04 PM, Avi Kivity wrote: > >> Those %ps are more or less useless. We need better ways of identifying >> them. >> > You're right, the vq pointer is useless in isolation. We don't know > which virtio device or which virtqueue number. > > With the full context of a trace it would be possible to correlate the > vq pointer if we had trace events for vdev and vq setup. > > Adding custom formatters is could be tricky since the format string is > passed only to tracing backends that use it, like UST. And UST uses > its own sprintf implementation which we don't have direct control > over. > Hm. Perhaps we can convert %{type} to %p for backends which don't support it, and to whatever format they do support for those that do. -- error compiling committee.c: too many arguments to function