@@ -18,16 +18,16 @@ struct plat_serial8250_port {
unsigned long iobase; /* io base address */
void __iomem *membase; /* ioremap cookie or NULL */
resource_size_t mapbase; /* resource base */
+ unsigned int uartclk; /* UART clock rate */
unsigned int irq; /* interrupt number */
unsigned long irqflags; /* request_irq flags */
- unsigned int uartclk; /* UART clock rate */
void *private_data;
unsigned char regshift; /* register shift */
unsigned char iotype; /* UPIO_* */
unsigned char hub6;
unsigned char has_sysrq; /* supports magic SysRq */
- upf_t flags; /* UPF_* flags */
unsigned int type; /* If UPF_FIXED_TYPE */
+ upf_t flags; /* UPF_* flags */
unsigned int (*serial_in)(struct uart_port *, int);
void (*serial_out)(struct uart_port *, int, int);
void (*set_termios)(struct uart_port *,
Group some variables based on their sizes to reduce hole and avoid padding. On x86_64, this shrinks the size of 'struct plat_serial8250_port' from 144 to 128 bytes. It saves a few bytes of memory. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- Using pahole Before: ====== struct plat_serial8250_port { long unsigned int iobase; /* 0 8 */ void * membase; /* 8 8 */ resource_size_t mapbase; /* 16 8 */ unsigned int irq; /* 24 4 */ /* XXX 4 bytes hole, try to pack */ long unsigned int irqflags; /* 32 8 */ unsigned int uartclk; /* 40 4 */ /* XXX 4 bytes hole, try to pack */ void * private_data; /* 48 8 */ unsigned char regshift; /* 56 1 */ unsigned char iotype; /* 57 1 */ unsigned char hub6; /* 58 1 */ unsigned char has_sysrq; /* 59 1 */ /* XXX 4 bytes hole, try to pack */ /* --- cacheline 1 boundary (64 bytes) --- */ upf_t flags; /* 64 8 */ unsigned int type; /* 72 4 */ /* XXX 4 bytes hole, try to pack */ unsigned int (*serial_in)(struct uart_port *, int); /* 80 8 */ void (*serial_out)(struct uart_port *, int, int); /* 88 8 */ void (*set_termios)(struct uart_port *, struct ktermios *, const struct ktermios *); /* 96 8 */ void (*set_ldisc)(struct uart_port *, struct ktermios *); /* 104 8 */ unsigned int (*get_mctrl)(struct uart_port *); /* 112 8 */ int (*handle_irq)(struct uart_port *); /* 120 8 */ /* --- cacheline 2 boundary (128 bytes) --- */ void (*pm)(struct uart_port *, unsigned int, unsigned int); /* 128 8 */ void (*handle_break)(struct uart_port *); /* 136 8 */ /* size: 144, cachelines: 3, members: 21 */ /* sum members: 128, holes: 4, sum holes: 16 */ /* last cacheline: 16 bytes */ }; After: ===== struct plat_serial8250_port { long unsigned int iobase; /* 0 8 */ void * membase; /* 8 8 */ resource_size_t mapbase; /* 16 8 */ unsigned int uartclk; /* 24 4 */ unsigned int irq; /* 28 4 */ long unsigned int irqflags; /* 32 8 */ void * private_data; /* 40 8 */ unsigned char regshift; /* 48 1 */ unsigned char iotype; /* 49 1 */ unsigned char hub6; /* 50 1 */ unsigned char has_sysrq; /* 51 1 */ unsigned int type; /* 52 4 */ upf_t flags; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */ unsigned int (*serial_in)(struct uart_port *, int); /* 64 8 */ void (*serial_out)(struct uart_port *, int, int); /* 72 8 */ void (*set_termios)(struct uart_port *, struct ktermios *, const struct ktermios *); /* 80 8 */ void (*set_ldisc)(struct uart_port *, struct ktermios *); /* 88 8 */ unsigned int (*get_mctrl)(struct uart_port *); /* 96 8 */ int (*handle_irq)(struct uart_port *); /* 104 8 */ void (*pm)(struct uart_port *, unsigned int, unsigned int); /* 112 8 */ void (*handle_break)(struct uart_port *); /* 120 8 */ /* size: 128, cachelines: 2, members: 21 */ }; --- include/linux/serial_8250.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)