From 47c61bc22285224ee24a7cbfa822c481f1155a81 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 7 Oct 2014 14:07:00 +0200 Subject: [PATCH 42/43] trace: add systemtap-initscript README file to RPM Message-id: <1412690820-31016-12-git-send-email-stefanha@redhat.com> Patchwork-id: 61616 O-Subject: [RHEL7.1 qemu-kvm PATCH 11/11] trace: add systemtap-initscript README file to RPM Bugzilla: 1088112 RH-Acked-by: Miroslav Rezanina RH-Acked-by: Laszlo Ersek RH-Acked-by: Paolo Bonzini The downstream systemtap-initscript integration is undocumented. Fix that with a brief guide containing usage instructions. Signed-off-by: Stefan Hajnoczi (cherry picked from commit d73b49dbbce7535531da5aa1dc640208f18979d2) Signed-off-by: Stefan Hajnoczi Signed-off-by: Miroslav Rezanina Conflicts: redhat/qemu-kvm.spec.template This patch is forward-ported from RHEL 6 qemu-kvm. RHEL 7's qemu-kvm.spec.template is significantly different from RHEL 6 so adjustments are necessary to include README.systemtap in the RPM. --- README.systemtap | 43 +++++++++++++++++++++++++++++++++++++++++++ redhat/qemu-kvm.spec.template | 3 ++- 2 files changed, 45 insertions(+), 1 deletion(-) create mode 100644 README.systemtap diff --git a/README.systemtap b/README.systemtap new file mode 100644 index 0000000..ad913fc --- /dev/null +++ b/README.systemtap @@ -0,0 +1,43 @@ +QEMU tracing using systemtap-initscript +--------------------------------------- + +You can capture QEMU trace data all the time using systemtap-initscript. This +uses SystemTap's flight recorder mode to trace all running guests to a +fixed-size buffer on the host. Old trace entries are overwritten by new +entries when the buffer size wraps. + +1. Install the systemtap-initscript package: + # yum install systemtap-initscript + +2. Install the systemtap scripts and the conf file: + # cp /usr/share/qemu-kvm/systemtap/script.d/qemu_kvm.stp /etc/systemtap/script.d/ + # cp /usr/share/qemu-kvm/systemtap/conf.d/qemu_kvm.conf /etc/systemtap/conf.d/ + +The set of trace events to enable is given in qemu_kvm.stp. This SystemTap +script can be customized to add or remove trace events provided in +/usr/share/systemtap/tapset/qemu-kvm-simpletrace.stp. + +SystemTap customizations can be made to qemu_kvm.conf to control the flight +recorder buffer size and whether to store traces in memory only or disk too. +See stap(1) for option documentation. + +3. Start the systemtap service. +　# service systemtap start qemu_kvm + +4. Make the service start at boot time. +　# chkconfig systemtap on + +5. Confirm that the service works. + # service systemtap status qemu_kvm + qemu_kvm is running... + +When you want to inspect the trace buffer, perform the following steps: + +1. Dump the trace buffer. + # staprun -A qemu_kvm >/tmp/trace.log + +2. Start the systemtap service because the preceding step stops the service. + # service systemtap start qemu_kvm + +3. Translate the trace record to readable format. + # /usr/share/qemu-kvm/simpletrace.py --no-header /usr/share/qemu-kvm/trace-events /tmp/trace.log -- 1.8.3.1