Re: Interface for SCSI transactions ?

[olafBuddenhagen]

Hi again,

On Fri, Sep 23, 2011 at 10:33:58PM +0200, Thomas Schmitt wrote:

> Am i allowed to make the RPC ugly if it reduces system load ?
> 
> 
> There seems to be an inavoidable performance penalty with my naive
> idea to allow an arbitrary reversible transformation from struct
> to byte array.
> In this case i have to copy the possibly fat payload buffer more often
> than i would have to if i get it separately and without need for
> conversion.
> 
> Separate payload buffers would yield a bloated RPC definition and
> C function prototype, i fear:
> 
>   routine device_transact_native(
>              device          : device_t;
>        in    function_code   : unsigned int;
>        in    in_ctrl         : ^ array[] of unsigned char;
>        in    in_data         : ^ array[] of unsigned char;
>        out   out_ctrl        : ^ array[] of unsigned char;
>        out   out_data        : ^ array[] of unsigned char
>        );

Well, in view of my other mail, you might see that I actually consider
this a step in the right direction... ;-)

But it makes it even more obvious that a generic device_transact() is a
bad idea.

-antrik-