Re: [Qemu-devel] [PATCH] kvm: add flightrecorder script

[Marcelo Tosatti]

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 <address@hidden>
> ---
>  scripts/kvm/kvm_flightrecorder |  126 
> ++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 126 insertions(+), 0 deletions(-)
>  create mode 100755 scripts/kvm/kvm_flightrecorder

Applied to uq/master, thanks.