Re: [Qemu-devel] Libvirt add ftrace option

[Gadre Nayan]

Ok. so I will then shift to using system tap, Are the timestamps
generated for events compatible with the ftrace timestamps? so that I
can still merge the traces using TSC_OFFSET.

Thanks,

On Tue, Aug 16, 2016 at 8:05 PM, Daniel P. Berrange <address@hidden> wrote:
> On Tue, Aug 16, 2016 at 07:54:50PM +0530, Gadre Nayan wrote:
>> Hi,
>>
>> I have setup the merging of traces from Guest QEMU and Host using the
>> TSC_OFFSET. So I would like to work with ftrace backend of QEMU. So
>> how can I add this option in libvirt tools to enable ftrace backends
>> with my custom qemu source built using --enable-trace-backends=ftrace.
>>
>> I would have to make changes to virt-install python script in the
>> virt-manager tools for starters ( to parse the trace options :). Where
>> else ?
>
> The need to modify the downstream tools to statically configure
> tracing parameters for VMs is exactly why we don't want to support
> things like ftrace in libvirt and recommend use of fully dymamic
> tracing like dtrace/systemd/ltt-ust.
>
> Regards,
> Daniel
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