From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:35548) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7bTY-00019V-Oj for qemu-devel@nongnu.org; Tue, 13 Mar 2012 19:50:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1S7bTX-0005GC-3c for qemu-devel@nongnu.org; Tue, 13 Mar 2012 19:49:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7252) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1S7bTW-0005Fo-S9 for qemu-devel@nongnu.org; Tue, 13 Mar 2012 19:49:55 -0400 Date: Tue, 13 Mar 2012 20:46:52 -0300 From: Marcelo Tosatti Message-ID: <20120313234652.GA15362@amt.cnet> References: <1331302420-29737-1-git-send-email-stefanha@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1331302420-29737-1-git-send-email-stefanha@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH] kvm: add flightrecorder script List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Anthony Liguori , qemu-devel@nongnu.org, kvm@vger.kernel.org, Avi Kivity On Fri, Mar 09, 2012 at 02:13:40PM +0000, Stefan Hajnoczi wrote: > The kvm kernel module includes a number of trace events which can be > useful when debugging system behavior. Even on production systems these > trace events can be used to observe guest behavior and identify the > source of problems. > > The kvm_flightrecorder script is a command-line wrapper for the > /sys/kernel/debug/tracing interface. Kernel symbols do not need to be > installed. > > This script captures a fixed-size buffer of KVM trace events. Recent > events overwrite the oldest events when the buffer size is exceeded and > it is possible to leave KVM tracing enabled for any period of time with > just a fixed-size buffer. If the buffer is large enough this script is > a useful tool for collecting detailed information after an issue occurs > with a guest. Hence the name "flight recorder". > > The script can also be used in 'tail' mode to simply view KVM trace > events as they occur. This is handy for development and to ensure that > the guest is indeed running. > > Signed-off-by: Stefan Hajnoczi > --- > scripts/kvm/kvm_flightrecorder | 126 ++++++++++++++++++++++++++++++++++++++++ > 1 files changed, 126 insertions(+), 0 deletions(-) > create mode 100755 scripts/kvm/kvm_flightrecorder Applied to uq/master, thanks.