The attached change fixes the "SLOW!" timer_interrupt warning that I
occassionally see on my rp3440 (800 MHz). We need to avoid using the
expensive div/mul method. I have seen instances where it takes more
than 0x7000 cycles.
Signed-off-by: John David Anglin <dave.anglin@xxxxxxxxxxxxxx>
Dave
--
J. David Anglin dave.anglin@xxxxxxxxxxxxxx
National Research Council of Canada (613) 990-0752 (FAX: 952-6602)
diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c
index 05511cc..63071c4 100644
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -76,7 +76,7 @@ irqreturn_t __irq_entry timer_interrupt(int irq, void *dev_id)
cycles_elapsed = now - next_tick;
- if ((cycles_elapsed >> 6) < cpt) {
+ if ((cycles_elapsed >> 7) < cpt) {
/* use "cheap" math (add/subtract) instead
* of the more expensive div/mul method
*/
--
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