Jan 30 2008

arch/x86/kernel/io_apic_{64,32}.c: use time_before 

Author: Julia Lawall <julia@diku.dk>

The functions time_before, time_before_eq, time_after, and time_after_eq
are more robust for comparing jiffies against other values.

A simplified version of the semantic patch making this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@ change_compare_np @
expression E;
@@

(
- jiffies <= E
+ time_before_eq(jiffies,E)
|
- jiffies >= E
+ time_after_eq(jiffies,E)
|
- jiffies < E
+ time_before(jiffies,E)
|
- jiffies > E
+ time_after(jiffies,E)
)

@ include depends on change_compare_np @
@@

#include 

@ no_include depends on !include && change_compare_np @
@@

  #include 
+ #include 
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner 

---
 arch/x86/kernel/io_apic_32.c | 5 +++--
 arch/x86/kernel/io_apic_64.c | 3 ++-
 2 files changed, 5 insertions(+), 3 deletions(-)
 
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 0d20423..4ca5486 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -35,6 +35,7 @@
 #include <linux/htirq.h>
 #include <linux/freezer.h>
 #include <linux/kthread.h>
+#include <linux/jiffies.h>	/* time_after() */
 
 #include <asm/io.h>
 #include <asm/smp.h>
@@ -349,7 +350,7 @@ static void set_ioapic_affinity_irq(unsigned int irq, cpumask_t cpumask)
 # include <asm/processor.h>	/* kernel_thread() */
 # include <linux/kernel_stat.h>	/* kstat */
 # include <linux/slab.h>		/* kmalloc() */
-# include <linux/timer.h>	/* time_after() */
+# include <linux/timer.h>
 
 #define IRQBALANCE_CHECK_ARCH -999
 #define MAX_BALANCED_IRQ_INTERVAL	(5*HZ)
@@ -1898,7 +1899,7 @@ static int __init timer_irq_works(void)
 	 * might have cached one ExtINT interrupt.  Finally, at
 	 * least one tick may be lost due to delays.
 	 */
-	if (jiffies - t1 > 4)
+	if (time_after(jiffies, t1 + 4))
 		return 1;
 
 	return 0;
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index f914d84..1627c0d 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -32,6 +32,7 @@
 #include <linux/msi.h>
 #include <linux/htirq.h>
 #include <linux/dmar.h>
+#include <linux/jiffies.h>
 #ifdef CONFIG_ACPI
 #include <acpi/acpi_bus.h>
 #endif
@@ -1299,7 +1300,7 @@ static int __init timer_irq_works(void)
 	 */
 
 	/* jiffies wrap? */
-	if (jiffies - t1 > 4)
+	if (time_after(jiffies, t1 + 4))
 		return 1;
 	return 0;
 }

qlambert