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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2005-05-01 08:58:57 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-01 08:58:57 -0700
commit4b7e0706620e3947dc1685dfdbc1413404afb545 (patch)
treec5ba1c919b6d1ca1141fbb0b6e9e0e933a51cc89 /arch/s390/kernel/time.c
parentb2c6678c858c5e54d95b996754adfb319cf65735 (diff)
[PATCH] s390: idle timer setup
Fix overflow in calculation of the new tod value in stop_hz_timer and fix wrong virtual timer list idle time in case the virtual timer is already expired in stop_cpu_timer. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/s390/kernel/time.c')
-rw-r--r--arch/s390/kernel/time.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 061e81138dc..8ca48567678 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -244,7 +244,7 @@ int sysctl_hz_timer = 1;
*/
static inline void stop_hz_timer(void)
{
- __u64 timer;
+ __u64 timer, todval;
if (sysctl_hz_timer != 0)
return;
@@ -265,8 +265,14 @@ static inline void stop_hz_timer(void)
* for the next event.
*/
timer = (__u64) (next_timer_interrupt() - jiffies) + jiffies_64;
- timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
- asm volatile ("SCKC %0" : : "m" (timer));
+ todval = -1ULL;
+ /* Be careful about overflows. */
+ if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
+ timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
+ if (timer >= jiffies_timer_cc)
+ todval = timer;
+ }
+ asm volatile ("SCKC %0" : : "m" (todval));
}
/*