timer: Use hlist for the timer wheel hash buckets
This reduces the size of struct tvec_base by 50% and results in
slightly smaller code as well.
Before:
struct tvec_base: size: 8256, cachelines: 129
text data bss dec hex filename
17698 13297 8256 39251 9953 ../build/kernel/time/timer.o
After:
struct tvec_base: 4160, cachelines: 65
text data bss dec hex filename
17491 9201 4160 30852 7884 ../build/kernel/time/timer.o
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Joonwoo Park <joonwoop@codeaurora.org>
Cc: Wenbo Wang <wenbo.wang@memblaze.com>
Link: http://lkml.kernel.org/r/20150526224511.854731214@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/timer.h b/include/linux/timer.h
index fbb80e0..064ee24 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -14,7 +14,7 @@
* All fields that change during normal runtime grouped to the
* same cacheline
*/
- struct list_head entry;
+ struct hlist_node entry;
unsigned long expires;
struct tvec_base *base;
@@ -71,7 +71,7 @@
#define TIMER_FLAG_MASK 0x3LU
#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
- .entry = { .prev = TIMER_ENTRY_STATIC }, \
+ .entry = { .next = TIMER_ENTRY_STATIC }, \
.function = (_function), \
.expires = (_expires), \
.data = (_data), \
@@ -168,7 +168,7 @@
*/
static inline int timer_pending(const struct timer_list * timer)
{
- return timer->entry.next != NULL;
+ return timer->entry.pprev != NULL;
}
extern void add_timer_on(struct timer_list *timer, int cpu);