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serial: max310x: remove holes in struct max310x_devtype

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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 */

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Link: https://lore.kernel.org/r/20240118152213.2644269-7-hugo@hugovil.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hugo Villeneuve 2024-01-18 10:22:02 -05:00 committed by Greg Kroah-Hartman
parent 8ede8c6f47
commit eaf29135ab
1 changed files with 2 additions and 2 deletions
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4
drivers/tty/serial/max310x.c
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@ -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 {