Re: [Qemu-devel] [PATCH 2/3] scsi: replace 'tag' with 'hba_private' pointer

[Hannes Reinecke]

On 07/01/2011 10:27 AM, Paolo Bonzini wrote:
> On 07/01/2011 09:42 AM, Hannes Reinecke wrote:
> > 'tag' is just an abstraction to identify the command
> > from the driver. So we should make that explicit by
> > replacing 'tag' with a driver-defined pointer 'hba_private'.
> > This saves the lookup for driver handling several commands
> > in parallel.
>
> This makes tracing a bit harder to follow. Perhaps you can keep the
> transport tag (a uint64_t) in the SCSIRequest for debugging purposes?
Hmm. The transport tag wouldn't have any meaning outside scsi-bus.c.
And it's a 64-bit value. So why can't we use the hba_private pointer 
directly here?
After some I/O has been ongoing the linear 'tag' number becomes 
unreadable very quickly, so there's not much difference here ...

Cheers,

Hannes
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Dr. Hannes Reinecke                   zSeries & Storage
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