2007-01-09 02:11:26

by Jeff Dike

[permalink] [raw]
Subject: [PATCH 2/7] UML - Make time data per-cpu

prev_nsecs and delta need to be arrays, and indexed by CPU number.

Signed-off-by: Jeff Dike <[email protected]>
--
arch/um/kernel/time.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)

Index: linux-2.6.18-mm/arch/um/kernel/time.c
===================================================================
--- linux-2.6.18-mm.orig/arch/um/kernel/time.c 2007-01-08 14:55:49.000000000 -0500
+++ linux-2.6.18-mm/arch/um/kernel/time.c 2007-01-08 16:14:01.000000000 -0500
@@ -35,31 +35,31 @@ unsigned long long sched_clock(void)
return (unsigned long long)jiffies_64 * (1000000000 / HZ);
}

-static unsigned long long prev_nsecs;
+static unsigned long long prev_nsecs[NR_CPUS];
#ifdef CONFIG_UML_REAL_TIME_CLOCK
-static long long delta; /* Deviation per interval */
+static long long delta[NR_CPUS]; /* Deviation per interval */
#endif

void timer_irq(union uml_pt_regs *regs)
{
unsigned long long ticks = 0;
-
#ifdef CONFIG_UML_REAL_TIME_CLOCK
- if(prev_nsecs){
+ int c = cpu();
+ if(prev_nsecs[c]){
/* We've had 1 tick */
unsigned long long nsecs = os_nsecs();

- delta += nsecs - prev_nsecs;
- prev_nsecs = nsecs;
+ delta[c] += nsecs - prev_nsecs[c];
+ prev_nsecs[c] = nsecs;

/* Protect against the host clock being set backwards */
- if(delta < 0)
- delta = 0;
+ if(delta[c] < 0)
+ delta[c] = 0;

- ticks += (delta * HZ) / BILLION;
- delta -= (ticks * BILLION) / HZ;
+ ticks += (delta[c] * HZ) / BILLION;
+ delta[c] -= (ticks * BILLION) / HZ;
}
- else prev_nsecs = os_nsecs();
+ else prev_nsecs[c] = os_nsecs();
#else
ticks = 1;
#endif
@@ -69,8 +69,8 @@ void timer_irq(union uml_pt_regs *regs)
}
}

+/* Protects local_offset */
static DEFINE_SPINLOCK(timer_spinlock);
-
static unsigned long long local_offset = 0;

static inline unsigned long long get_time(void)