[Intel-gfx] [PATCH 1/2] drm/i915: Introduce execlist_port_* accessors

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> Quoting Mika Kuoppala (2017-11-02 10:38:30)
>> Chris Wilson <chris at chris-wilson.co.uk> writes:
>> 
>> > Quoting Mika Kuoppala (2017-10-31 15:27:33)
>> >> +static inline struct execlist_port *
>> >> +execlists_port_next(struct intel_engine_execlists * const execlists,
>> >> +                   const struct execlist_port * const port)
>> >> +{
>> >> +       const unsigned int n = __port_add(port_index(port, execlists),
>> >> +                                         1,
>> >> +                                         execlists->port_mask);
>> >
>> > How does this compare to
>> >
>> >       if (port++ == execlists->port + execlists->port_mask)
>> >               port = execlists->port;
>> >
>> >       return port;
>> > ?
>> 
>> add/remove: 0/0 grow/shrink: 1/1 up/down: 29/-29 (0)
>> function                                     old     new   delta
>> i915_guc_irq_handler                        2584    2613     +29
>> intel_lrc_irq_handler                       2963    2934     -29
>> Total: Before=1123627, After=1123627, chg +0.00%
>
> Hmm, your functions saw little difference and are twice as big as
> mine... Weird.
>
> I used gcc version 6.3.0 20170516 (Debian 6.3.0-18) with defconfig.
> Yourself?

I had debugs on, sigh...

Now with the defconfig and gcc (Ubuntu 6.3.0-12ubuntu2) 6.3.0 20170406:

add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-139 (-139)
function                                     old     new   delta
i915_guc_irq_handler                        1620    1617      -3
intel_lrc_irq_handler                       1926    1790    -136

So we have a clear winner.

-Mika