Re: MSEC_TO_JIFFIES is messed up...

On Wed, 12 May 2004 22:50:28 +0200, Ingo Molnar said:

1) - 1)

 
 #endif
+
+/*
+ * Convert jiffies to milliseconds and back.
+ *
+ * Avoid unnecessary multiplications/divisions in the
+ * two most common HZ cases:
+ */
+#if HZ == 1000
+# define JIFFIES_TO_MSECS(x)	(x)
+# define MSECS_TO_JIFFIES(x)	(x)
+#elif HZ == 100
+# define JIFFIES_TO_MSECS(x)	((x) * 10)
+# define MSECS_TO_JIFFIES(x)	((x) / 10)
+#else
+# define JIFFIES_TO_MSECS(x)	((x) * 1000 / HZ)
+# define MSECS_TO_JIFFIES(x)	((x) * HZ / 1000)
+#endif
+

Looks good to me.. :)

On Wed, 12 May 2004 Valdis.Kletnieks@vt.edu wrote:

On Wed, 12 May 2004 22:50:28 +0200, Ingo Molnar said:

quoted

Content-Disposition: attachment; filename="hz-cleanup-2.6.6-A2"

--- linux/include/linux/time.h.orig	
+++ linux/include/linux/time.h	

@@ -177,6 +177,24 @@ struct timezone {
 	(SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 

1) - 1)

quoted

 
 #endif
+
+/*
+ * Convert jiffies to milliseconds and back.
+ *
+ * Avoid unnecessary multiplications/divisions in the
+ * two most common HZ cases:
+ */
+#if HZ == 1000
+# define JIFFIES_TO_MSECS(x)	(x)
+# define MSECS_TO_JIFFIES(x)	(x)
+#elif HZ == 100
+# define JIFFIES_TO_MSECS(x)	((x) * 10)
+# define MSECS_TO_JIFFIES(x)	((x) / 10)
+#else
+# define JIFFIES_TO_MSECS(x)	((x) * 1000 / HZ)
+# define MSECS_TO_JIFFIES(x)	((x) * HZ / 1000)
+#endif
+

Looks good to me.. :)

Guys, why don't you leave the compiler to do its job?



- Davide