clocksource: Restructure clocksource struct members

Group the hot path members of struct clocksource together so we have a
better cache line footprint. Make it cacheline aligned.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/%3C20110518210136.003081882%40linutronix.de%3E
This commit is contained in:
Thomas Gleixner 2011-05-18 21:33:40 +00:00
parent a18f22a968
commit 369db4c952

View File

@ -159,42 +159,38 @@ extern u64 timecounter_cyc2time(struct timecounter *tc,
*/
struct clocksource {
/*
* First part of structure is read mostly
* Hotpath data, fits in a single cache line when the
* clocksource itself is cacheline aligned.
*/
const char *name;
struct list_head list;
int rating;
cycle_t (*read)(struct clocksource *cs);
int (*enable)(struct clocksource *cs);
void (*disable)(struct clocksource *cs);
cycle_t cycle_last;
cycle_t mask;
u32 mult;
u32 shift;
u64 max_idle_ns;
unsigned long flags;
cycle_t (*vread)(void);
void (*suspend)(struct clocksource *cs);
void (*resume)(struct clocksource *cs);
#ifdef CONFIG_IA64
void *fsys_mmio; /* used by fsyscall asm code */
#define CLKSRC_FSYS_MMIO_SET(mmio, addr) ((mmio) = (addr))
#else
#define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0)
#endif
/*
* Second part is written at each timer interrupt
* Keep it in a different cache line to dirty no
* more than one cache line.
*/
cycle_t cycle_last ____cacheline_aligned_in_smp;
const char *name;
struct list_head list;
int rating;
cycle_t (*vread)(void);
int (*enable)(struct clocksource *cs);
void (*disable)(struct clocksource *cs);
unsigned long flags;
void (*suspend)(struct clocksource *cs);
void (*resume)(struct clocksource *cs);
#ifdef CONFIG_CLOCKSOURCE_WATCHDOG
/* Watchdog related data, used by the framework */
struct list_head wd_list;
cycle_t wd_last;
#endif
};
} ____cacheline_aligned;
/*
* Clock source flags bits::