From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rayson Ho Subject: Re: Tracing KVM with Systemtap Date: Tue, 21 Sep 2010 08:58:07 -0400 Message-ID: <1285073887.2566.39.camel@computer> References: <1283952030.2631.19.camel@computer> <1284988762.2500.13.camel@computer> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, systemtap@sources.redhat.com, Prerna Saxena To: Stefan Hajnoczi Return-path: Received: from mx1.redhat.com ([209.132.183.28]:3727 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754703Ab0IUNAS (ORCPT ); Tue, 21 Sep 2010 09:00:18 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Mon, 2010-09-20 at 14:36 +0100, Stefan Hajnoczi wrote: > Right now there are few pre-defined probes ("trace events" in QEMU > tracing speak). As I develop I try to be mindful of new ones I create > and whether they would be generally useful. I intend to contribute > more probes and hope others will too! I am still looking at/hacking the QEMU code. I have looked at the following places in the code that I think can be useful to have statistics gathered: net.c qemu_deliver_packet(), etc - network statistics /op_helper.c global_cpu_lock(), tlb_fill() - lock & unlock, and TLB refill statistics balloon.c, hw/virtio-balloon.c - ballooning information. Besides the ballooning part, which I know what it is but don't fully understand how it works, the other parts can be implemented as Systemtap tapsets (~ "DTrace scripts") in the initial stage. I will see what other probes are useful for the end users. Also, are there developer documentations for KVM? (I googled but found a lot of presentations about KVM but not a lot of info about the internals.) Rayson > > Prerna is also looking at adding useful probes. > > Stefan