linux-kernel - Re: [PATCH] gpio: reduce descriptor validation code size

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Date:   Thu, 21 Dec 2017 13:53:45 +0100
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Rasmus Villemoes <linux@...musvillemoes.dk>
Cc:     linux-gpio@...r.kernel.org,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] gpio: reduce descriptor validation code size

On Thu, Dec 21, 2017 at 1:27 AM, Rasmus Villemoes
<linux@...musvillemoes.dk> wrote:

> While we do need macros to be able to return from the "calling"
> function, we can still factor the checks done by the VALIDATE_DESC*
> macros into a real helper function. This reduces the backslashtitis,
> avoids duplicating the logic in the two macros and saves about 1K of
> generated code:
>
> $ scripts/bloat-o-meter drivers/gpio/gpiolib.o.{0,1}
> add/remove: 1/0 grow/shrink: 0/15 up/down: 104/-1281 (-1177)
> Function                                     old     new   delta
> validate_desc                                  -     104    +104
> gpiod_set_value                              192     135     -57
> gpiod_set_raw_value                          125      67     -58
> gpiod_direction_output                       412     351     -61
> gpiod_set_value_cansleep                     150      70     -80
> gpiod_set_raw_value_cansleep                 132      52     -80
> gpiod_get_raw_value                          139      54     -85
> gpiod_set_debounce                           226     140     -86
> gpiod_direction_output_raw                   124      38     -86
> gpiod_get_value                              161      74     -87
> gpiod_cansleep                               126      39     -87
> gpiod_get_raw_value_cansleep                 130      39     -91
> gpiod_get_value_cansleep                     152      59     -93
> gpiod_is_active_low                          128      33     -95
> gpiod_request                                299     184    -115
> gpiod_direction_input                        386     266    -120
> Total: Before=25460, After=24283, chg -4.62%
>
> Signed-off-by: Rasmus Villemoes <linux@...musvillemoes.dk>

Excellent patch! Very happy with this.

Patch applied, naturally :)

Yours,
Linus Walleij