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authorTony Luck <tony.luck@intel.com>2005-09-08 14:27:13 -0700
committerTony Luck <tony.luck@intel.com>2005-09-08 14:27:13 -0700
commit344a076110f4ecb16ea6d286b63be696604982ed (patch)
treedef6e229efdb6ee91b631b6695bf7f9ace8e2719 /kernel/timer.c
parent9b17e7e74e767d8a494a74c3c459aeecd1e08c5f (diff)
parent1b11d78cf87a7014f96e5b7fa2e1233cc8081a00 (diff)
[IA64] Manual merge fix for 3 files
arch/ia64/Kconfig arch/ia64/kernel/acpi.c include/asm-ia64/irq.h Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'kernel/timer.c')
-rw-r--r--kernel/timer.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/kernel/timer.c b/kernel/timer.c
index 5377f40723ff..13e2b513be01 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -950,6 +950,7 @@ void do_timer(struct pt_regs *regs)
{
jiffies_64++;
update_times();
+ softlockup_tick(regs);
}
#ifdef __ARCH_WANT_SYS_ALARM
@@ -1428,7 +1429,7 @@ static inline u64 time_interpolator_get_cycles(unsigned int src)
}
}
-static inline u64 time_interpolator_get_counter(void)
+static inline u64 time_interpolator_get_counter(int writelock)
{
unsigned int src = time_interpolator->source;
@@ -1442,6 +1443,15 @@ static inline u64 time_interpolator_get_counter(void)
now = time_interpolator_get_cycles(src);
if (lcycle && time_after(lcycle, now))
return lcycle;
+
+ /* When holding the xtime write lock, there's no need
+ * to add the overhead of the cmpxchg. Readers are
+ * force to retry until the write lock is released.
+ */
+ if (writelock) {
+ time_interpolator->last_cycle = now;
+ return now;
+ }
/* Keep track of the last timer value returned. The use of cmpxchg here
* will cause contention in an SMP environment.
*/
@@ -1455,7 +1465,7 @@ static inline u64 time_interpolator_get_counter(void)
void time_interpolator_reset(void)
{
time_interpolator->offset = 0;
- time_interpolator->last_counter = time_interpolator_get_counter();
+ time_interpolator->last_counter = time_interpolator_get_counter(1);
}
#define GET_TI_NSECS(count,i) (((((count) - i->last_counter) & (i)->mask) * (i)->nsec_per_cyc) >> (i)->shift)
@@ -1467,7 +1477,7 @@ unsigned long time_interpolator_get_offset(void)
return 0;
return time_interpolator->offset +
- GET_TI_NSECS(time_interpolator_get_counter(), time_interpolator);
+ GET_TI_NSECS(time_interpolator_get_counter(0), time_interpolator);
}
#define INTERPOLATOR_ADJUST 65536
@@ -1490,7 +1500,7 @@ static void time_interpolator_update(long delta_nsec)
* and the tuning logic insures that.
*/
- counter = time_interpolator_get_counter();
+ counter = time_interpolator_get_counter(1);
offset = time_interpolator->offset + GET_TI_NSECS(counter, time_interpolator);
if (delta_nsec < 0 || (unsigned long) delta_nsec < offset)