[PATCH] CFS : Use NSEC_PER_MSEC and NSEC_PER_SEC in kernel/sched.cand kernel/sysctl.c

From: Eric Dumazet
Date: Wed Oct 31 2007 - 01:09:21 EST


1) hardcoded 1000000000 value is used five times in places where NSEC_PER_SEC might be more readable.

2) A conversion from nsec to msec uses the hardcoded 1000000 value, which is a candidate for NSEC_PER_MSEC.

Signed-off-by: Eric Dumazet <dada1@xxxxxxxxxxxxx>

diff --git a/kernel/sched.c b/kernel/sched.c
index 3f6bd11..57c539d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -75,7 +75,7 @@
*/
unsigned long long __attribute__((weak)) sched_clock(void)
{
- return (unsigned long long)jiffies * (1000000000 / HZ);
+ return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
}

/*
@@ -99,8 +99,8 @@ unsigned long long __attribute__((weak)) sched_clock(void)
/*
* Some helpers for converting nanosecond timing to jiffy resolution
*/
-#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (1000000000 / HZ))
-#define JIFFIES_TO_NS(TIME) ((TIME) * (1000000000 / HZ))
+#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
+#define JIFFIES_TO_NS(TIME) ((TIME) * (NSEC_PER_SEC / HZ))

#define NICE_0_LOAD SCHED_LOAD_SCALE
#define NICE_0_SHIFT SCHED_LOAD_SHIFT
@@ -7228,7 +7228,7 @@ static u64 cpu_usage_read(struct cgroup *cgrp, struct cftype *cft)
spin_unlock_irqrestore(&cpu_rq(i)->lock, flags);
}
/* Convert from ns to ms */
- do_div(res, 1000000);
+ do_div(res, NSEC_PER_MSEC);

return res;
}
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3b4efbe..6547f9a 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -226,9 +226,9 @@ static struct ctl_table root_table[] = {

#ifdef CONFIG_SCHED_DEBUG
static unsigned long min_sched_granularity_ns = 100000; /* 100 usecs */
-static unsigned long max_sched_granularity_ns = 1000000000; /* 1 second */
+static unsigned long max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
static unsigned long min_wakeup_granularity_ns; /* 0 usecs */
-static unsigned long max_wakeup_granularity_ns = 1000000000; /* 1 second */
+static unsigned long max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
#endif

static struct ctl_table kern_table[] = {