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* [PATCH 3/15] arch/ia64: Use DIV_ROUND_CLOSEST
@ 2009-08-02  8:45 Julia Lawall
  2009-08-04 22:09 ` [PATCH 1/4] Bug Fix drivers/pci/intel-iommu.c: correct sglist size calculation Fenghua Yu
  2009-08-05 23:22 ` [PATCH 3/15] arch/ia64: Use DIV_ROUND_CLOSEST Yu, Fenghua
  0 siblings, 2 replies; 4+ messages in thread
From: Julia Lawall @ 2009-08-02  8:45 UTC (permalink / raw)
  To: fenghua.yu, tony.luck, linux-ia64, linux-kernel, kernel-janitors

From: Julia Lawall <julia@diku.dk>

The kernel.h macro DIV_ROUND_CLOSEST performs the computation (x + d/2)/d
but is perhaps more readable.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@haskernel@
@@

#include <linux/kernel.h>

@depends on haskernel@
expression x,__divisor;
@@

- (((x) + ((__divisor) / 2)) / (__divisor))
+ DIV_ROUND_CLOSEST(x,__divisor)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 arch/ia64/kernel/time.c             |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 4990495..aaa6651 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -314,7 +314,7 @@ ia64_init_itm (void)
 
 	itc_freq = (platform_base_freq*itc_ratio.num)/itc_ratio.den;
 
-	local_cpu_data->itm_delta = (itc_freq + HZ/2) / HZ;
+	local_cpu_data->itm_delta = DIV_ROUND_CLOSEST(itc_freq, HZ);
 	printk(KERN_DEBUG "CPU %d: base freq=%lu.%03luMHz, ITC ratio=%u/%u, "
 	       "ITC freq=%lu.%03luMHz", smp_processor_id(),
 	       platform_base_freq / 1000000, (platform_base_freq / 1000) % 1000,
@@ -330,9 +330,11 @@ ia64_init_itm (void)
 
 	local_cpu_data->proc_freq = (platform_base_freq*proc_ratio.num)/proc_ratio.den;
 	local_cpu_data->itc_freq = itc_freq;
-	local_cpu_data->cyc_per_usec = (itc_freq + USEC_PER_SEC/2) / USEC_PER_SEC;
-	local_cpu_data->nsec_per_cyc = ((NSEC_PER_SEC<<IA64_NSEC_PER_CYC_SHIFT)
-					+ itc_freq/2)/itc_freq;
+	local_cpu_data->cyc_per_usec =
+		DIV_ROUND_CLOSEST(itc_freq, USEC_PER_SEC);
+	local_cpu_data->nsec_per_cyc =
+		DIV_ROUND_CLOSEST(NSEC_PER_SEC << IA64_NSEC_PER_CYC_SHIFT,
+				  itc_freq);
 
 	if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) {
 #ifdef CONFIG_SMP


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2009-08-05 23:22 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-08-02  8:45 [PATCH 3/15] arch/ia64: Use DIV_ROUND_CLOSEST Julia Lawall
2009-08-04 22:09 ` [PATCH 1/4] Bug Fix drivers/pci/intel-iommu.c: correct sglist size calculation Fenghua Yu
2009-08-05  7:59   ` David Woodhouse
2009-08-05 23:22 ` [PATCH 3/15] arch/ia64: Use DIV_ROUND_CLOSEST Yu, Fenghua

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