[PATCH] dyn-tick3 tweaks

From: Con Kolivas
Date: Thu Aug 04 2005 - 19:29:11 EST


On Fri, 5 Aug 2005 10:05 am, Con Kolivas wrote:
> Looking yet further into this, if it gotos monotonic_base it will return
> without using any of these variables so it's a harmless warning but we may
> as well initialise them to quieten it.

Something like this on top is cleaner and quieter. I'll add this to pending
changes for another version.

Cheers,
Con
---


Index: linux-2.6.13-rc5-ck2/arch/i386/kernel/timers/timer_tsc.c
===================================================================
--- linux-2.6.13-rc5-ck2.orig/arch/i386/kernel/timers/timer_tsc.c 2005-08-03 11:29:29.000000000 +1000
+++ linux-2.6.13-rc5-ck2/arch/i386/kernel/timers/timer_tsc.c 2005-08-05 10:22:25.000000000 +1000
@@ -167,10 +167,20 @@ static void delay_tsc(unsigned long loop
} while ((now-bclock) < loops);
}

+/* update the monotonic base value */
+static inline void update_monotonic_base(unsigned long long last_offset)
+{
+ unsigned long long this_offset;
+
+ this_offset = ((unsigned long long)last_tsc_high << 32) | last_tsc_low;
+ monotonic_base += cycles_2_ns(this_offset - last_offset);
+ write_sequnlock(&monotonic_lock);
+}
+
#ifdef CONFIG_HPET_TIMER
static void mark_offset_tsc_hpet(void)
{
- unsigned long long this_offset, last_offset;
+ unsigned long long last_offset;
unsigned long offset, temp, hpet_current;

write_seqlock(&monotonic_lock);
@@ -198,10 +208,7 @@ static void mark_offset_tsc_hpet(void)
}
hpet_last = hpet_current;

- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- monotonic_base += cycles_2_ns(this_offset - last_offset);
- write_sequnlock(&monotonic_lock);
+ update_monotonic_base(last_offset);

/* calculate delay_at_last_interrupt */
/*
@@ -347,7 +354,7 @@ static void mark_offset_tsc(void)
int count;
int countmp;
static int count1 = 0;
- unsigned long long this_offset, last_offset;
+ unsigned long long last_offset;
static int lost_count = 0;

write_seqlock(&monotonic_lock);
@@ -368,8 +375,10 @@ static void mark_offset_tsc(void)

rdtsc(last_tsc_low, last_tsc_high);

- if (dyn_tick_enabled())
- goto monotonic_base;
+ if (dyn_tick_enabled()) {
+ update_monotonic_base(last_offset);
+ return;
+ }

spin_lock(&i8253_lock);
outb_p(0x00, PIT_MODE); /* latch the count ASAP */
@@ -439,15 +448,7 @@ static void mark_offset_tsc(void)
} else
lost_count = 0;

- monotonic_base:
-
- /* update the monotonic base value */
- this_offset = ((unsigned long long)last_tsc_high<<32)|last_tsc_low;
- monotonic_base += cycles_2_ns(this_offset - last_offset);
- write_sequnlock(&monotonic_lock);
-
- if (dyn_tick_enabled())
- return;
+ update_monotonic_base(last_offset);

/* calculate delay_at_last_interrupt */
count = ((LATCH-1) - count) * TICK_SIZE;