From: David Lechner <david@lechnology.com>
To: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"William Breathitt Gray" <vilhelm.gray@gmail.com>
Cc: linux-iio@vger.kernel.org, kernel@pengutronix.de
Subject: Re: [PATCH] counter: ti-eqep: Use container_of instead of struct counter_device::priv
Date: Mon, 13 Dec 2021 09:50:02 -0600 [thread overview]
Message-ID: <759aa00b-89b4-e1b9-bfbc-bda2e96d0bd7@lechnology.com> (raw)
In-Reply-To: <20211213114312.1406562-1-u.kleine-koenig@pengutronix.de>
On 12/13/21 5:43 AM, Uwe Kleine-König wrote:
> Using counter->priv is a memory read and so more expensive than
> container_of which is only an addition. (In this case even a noop
> because the offset is 0.)
>
> So container_of is expected to be a tad faster, it's type-safe, and
> produces smaller code (ARCH=arm allmodconfig):
>
> $ source/scripts/bloat-o-meter drivers/counter/ti-eqep.o-pre drivers/counter/ti-eqep.o
> add/remove: 0/0 grow/shrink: 0/9 up/down: 0/-108 (-108)
> Function old new delta
> ti_eqep_position_enable_write 132 120 -12
> ti_eqep_position_enable_read 260 248 -12
> ti_eqep_position_ceiling_write 132 120 -12
> ti_eqep_position_ceiling_read 236 224 -12
> ti_eqep_function_write 220 208 -12
> ti_eqep_function_read 372 360 -12
> ti_eqep_count_write 312 300 -12
> ti_eqep_count_read 236 224 -12
> ti_eqep_action_read 664 652 -12
> Total: Before=4598, After=4490, chg -2.35%
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
Acked-by: David Lechner <david@lechnology.com>
next prev parent reply other threads:[~2021-12-13 15:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-13 11:43 [PATCH] counter: ti-eqep: Use container_of instead of struct counter_device::priv Uwe Kleine-König
2021-12-13 15:50 ` David Lechner [this message]
2021-12-16 5:25 ` William Breathitt Gray
2021-12-16 10:49 ` Uwe Kleine-König
2021-12-16 23:31 ` William Breathitt Gray
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