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From: Hugo Villeneuve <hugo@hugovil.com>
To: gregkh@linuxfoundation.org, jirislaby@kernel.org,
	cosmin.tanislav@analog.com, andy.shevchenko@gmail.com,
	shc_work@mail.ru
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
	hugo@hugovil.com, Hugo Villeneuve <hvilleneuve@dimonoff.com>
Subject: [PATCH 06/18] serial: max310x: remove holes in struct max310x_devtype
Date: Wed, 17 Jan 2024 17:38:44 -0500	[thread overview]
Message-ID: <20240117223856.2303475-7-hugo@hugovil.com> (raw)
In-Reply-To: <20240117223856.2303475-1-hugo@hugovil.com>

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

Running pahole shows that there are some holes within the
max310x_devtype structure.

Remove holes and optimize alignment by reorganizing structure members.

This can also lead to data structure size reduction for some CPUs.

On 64-bit CPU (arm64):
Before:
    /* size: 40, cachelines: 1, members: 6 */
    /* sum members: 34, holes: 2, sum holes: 6 */
    /* last cacheline: 40 bytes */
After:
    /* size: 40, cachelines: 1, members: 6 */
    /* padding: 6 */
    /* last cacheline: 40 bytes */

On 32-bit CPU (i386):
Before:
    /* size: 32, cachelines: 1, members: 6 */
    /* sum members: 26, holes: 2, sum holes: 6 */
    /* last cacheline: 32 bytes */
After:
    /* size: 24, cachelines: 1, members: 8 */
    /* padding: 2 */
    /* last cacheline: 24 bytes */

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
 drivers/tty/serial/max310x.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c
index 27c8ec956691..21f2fa3a91e5 100644
--- a/drivers/tty/serial/max310x.c
+++ b/drivers/tty/serial/max310x.c
@@ -258,11 +258,11 @@ struct max310x_devtype {
 		unsigned short min;
 		unsigned short max;
 	} slave_addr;
-	char	name[9];
 	int	nr;
-	u8	mode1;
 	int	(*detect)(struct device *);
 	void	(*power)(struct uart_port *, int);
+	char	name[9];
+	u8	mode1;
 };
 
 struct max310x_one {
-- 
2.39.2


  parent reply	other threads:[~2024-01-17 22:39 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-17 22:38 [PATCH 00/18] serial: max310x: cleanups and improvements Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 01/18] serial: max310x: fix NULL pointer dereference in I2C instantiation Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 02/18] serial: max310x: add I2C device table for instantiation from userspace Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 03/18] serial: max310x: use i2c_get_match_data() Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 04/18] serial: max310x: use spi_get_device_match_data() Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 05/18] serial: max310x: fix syntax error in IRQ error message Hugo Villeneuve
2024-01-17 22:38 ` Hugo Villeneuve [this message]
2024-01-17 22:38 ` [PATCH 07/18] serial: max310x: add macro for max number of ports Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 08/18] serial: max310x: use separate regmap name for each port Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 09/18] serial: max310x: simplify probe() and remove() error handling Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 10/18] serial: max310x: add explicit return for some switch default cases Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 11/18] serial: max310x: use dev_err_probe() instead of dev_err() Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 12/18] serial: max310x: replace hardcoded masks with preferred GENMASK() Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 13/18] serial: max310x: use common detect function for all variants Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 14/18] serial: max310x: use common power " Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 15/18] serial: max310x: replace ENOTSUPP with preferred EOPNOTSUPP (checkpatch) Hugo Villeneuve
2024-01-17 23:24   ` Andy Shevchenko
2024-01-17 23:59     ` Hugo Villeneuve
2024-01-18  8:59       ` Andy Shevchenko
2024-01-18 13:15         ` Kent Gibson
2024-01-17 22:38 ` [PATCH 16/18] serial: max310x: replace bare use of 'unsigned' with 'unsigned int' (checkpatch) Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 17/18] serial: max310x: reformat and improve comments Hugo Villeneuve
2024-01-17 22:38 ` [PATCH 18/18] serial: max310x: fix indentation Hugo Villeneuve
2024-01-17 23:26 ` [PATCH 00/18] serial: max310x: cleanups and improvements Andy Shevchenko
2024-01-18  0:00   ` Hugo Villeneuve

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