Being of type unsigned long, the struct clock_event_device's ->retries
member is incremented in clockevents_program_min_delta() and used for
diagnostic purposes in /proc/timer_list only.
Turning ->retries' type into unsigned int avoids the introduction of
some padding with future reorderings of struct clock_event_device for the
case of sizeof(unsigned long) == sizeof(void*) == 8. This is turn prevents
these reorganizations from making sizeof(struct clock_event_device) cross
a multiple of the cacheline size, assumed to be equal to 64 bytes.
For the case of HZ=1000, this change still allows for
2^32 / HZ / (3600*24) = 49 days without overwrap, even in the highly
unrealistic case of one clockevents_program_min_delta() invocation per
tick.
Thus, change ->retries' type from unsigned long to unsigned int. Adapt
the format specifier or /proc/timer_list accordingly.
Signed-off-by: Nicolai Stange <nicsta...@gmail.com>
---
include/linux/clockchips.h | 2 +-
kernel/time/timer_list.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
index e07f421..878a802 100644
--- a/include/linux/clockchips.h
+++ b/include/linux/clockchips.h
@@ -115,7 +115,7 @@ struct clock_event_device {
u32 shift;
enum clock_event_state state_use_accessors:8;
unsigned int features:24;
- unsigned long retries;
+ unsigned int retries;
int (*set_state_periodic)(struct clock_event_device
*);
int (*set_state_oneshot)(struct clock_event_device
*);
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 9067760..6a8d54f 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -271,7 +271,7 @@ print_tickdevice(struct seq_file *m, struct tick_device
*td, int cpu)
SEQ_printf(m, " event_handler: ");
print_name_offset(m, dev->event_handler);
SEQ_printf(m, "\n");
- SEQ_printf(m, " retries: %lu\n", dev->retries);
+ SEQ_printf(m, " retries: %u\n", dev->retries);
SEQ_printf(m, "\n");
}
--
2.10.2
