[Qemu-devel] Re: [PATCH 7/7] trace: Trace virtqueue operations

[Avi Kivity <avi@redhat.com>]

On 05/25/2010 04:27 PM, Stefan Hajnoczi wrote:
> On Tue, May 25, 2010 at 1:04 PM, Avi Kivity<avi@redhat.com>  wrote:
>    
>> Those %ps are more or less useless.  We need better ways of identifying
>> them.
>>      
> You're right, the vq pointer is useless in isolation.  We don't know
> which virtio device or which virtqueue number.
>
> With the full context of a trace it would be possible to correlate the
> vq pointer if we had trace events for vdev and vq setup.
>
> Adding custom formatters is could be tricky since the format string is
> passed only to tracing backends that use it, like UST.  And UST uses
> its own sprintf implementation which we don't have direct control
> over.
>    

Hm.  Perhaps we can convert %{type} to %p for backends which don't 
support it, and to whatever format they do support for those that do.

-- 
error compiling committee.c: too many arguments to function