From: Andrew Morton <akpm@linux-foundation.org>
Date: Wed, 6 Feb 2008 09:38:06 +0000 (-0800)
Subject: speed up jiffies conversion functions if HZ==USER_HZ
X-Git-Tag: v2.6.25-rc1~664
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ec03d7073971e20a866448d62c992a168201ac82;p=linux-2.6

speed up jiffies conversion functions if HZ==USER_HZ

Avoid calling do_div(x, 1) in this case.

Cc: David Fries <david@fries.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/time.c b/kernel/time.c
index be5c8cb935..33af3e5557 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -606,8 +606,10 @@ u64 jiffies_64_to_clock_t(u64 x)
 # if HZ < USER_HZ
 	x *= USER_HZ;
 	do_div(x, HZ);
-# else
+# elif HZ > USER_HZ
 	do_div(x, HZ / USER_HZ);
+# else
+	/* Nothing to do */
 # endif
 #else
 	/*