| Message ID | 1351520658-23028-1-git-send-email-linus.walleij@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Oct 29, 2012 at 02:24:18PM +0000, Linus Walleij wrote: > This will make the two crucial integer divisions in the generic > ARM arch timer used for ARMv8 use the kernel DIV_ROUND_CLOSEST() > helper inline from <linux/kernel.h> so they get more precise. > > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> BTW, would this go through John's tree? I'm happy to push it as well. Thanks.
On 10/29/2012 07:24 AM, Linus Walleij wrote: > This will make the two crucial integer divisions in the generic > ARM arch timer used for ARMv8 use the kernel DIV_ROUND_CLOSEST() > helper inline from <linux/kernel.h> so they get more precise. > > Cc: Marc Zyngier <marc.zyngier@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Applied. Thanks -john
diff --git a/drivers/clocksource/arm_generic.c b/drivers/clocksource/arm_generic.c index c4d9f95..6cd1b30 100644 --- a/drivers/clocksource/arm_generic.c +++ b/drivers/clocksource/arm_generic.c @@ -127,7 +127,7 @@ static void __init arch_timer_calibrate(void) /* Cache the sched_clock multiplier to save a divide in the hot path. */ - sched_clock_mult = NSEC_PER_SEC / arch_timer_rate; + sched_clock_mult = DIV_ROUND_CLOSEST(NSEC_PER_SEC, arch_timer_rate); pr_info("Architected local timer running at %u.%02uMHz.\n", arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100); @@ -221,7 +221,7 @@ int __init arm_generic_timer_init(void) clocksource_register_hz(&clocksource_counter, arch_timer_rate); /* Calibrate the delay loop directly */ - lpj_fine = arch_timer_rate / HZ; + lpj_fine = DIV_ROUND_CLOSEST(arch_timer_rate, HZ); /* Immediately configure the timer on the boot CPU */ arch_timer_setup(per_cpu_ptr(&arch_timer_evt, smp_processor_id()));
This will make the two crucial integer divisions in the generic ARM arch timer used for ARMv8 use the kernel DIV_ROUND_CLOSEST() helper inline from <linux/kernel.h> so they get more precise. Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- drivers/clocksource/arm_generic.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)