vserver 1.9.3

[linux-2.6.git] / include / linux / acct.h

diff --git a/include/linux/acct.h b/include/linux/acct.h
index b46ce1a..a6ab17c 100644 (file)
--- a/include/linux/acct.h
+++ b/include/linux/acct.h
@@ -172,17 +172,24 @@ static inline u32 jiffies_to_AHZ(unsigned long x)
 #endif
 }
 
-static inline u64 jiffies_64_to_AHZ(u64 x)
+static inline u64 nsec_to_AHZ(u64 x)
 {
-#if (TICK_NSEC % (NSEC_PER_SEC / AHZ)) == 0
-#if HZ != AHZ
-       do_div(x, HZ / AHZ);
-#endif
-#else
-       x *= TICK_NSEC;
+#if (NSEC_PER_SEC % AHZ) == 0
        do_div(x, (NSEC_PER_SEC / AHZ));
+#elif (AHZ % 512) == 0
+       x *= AHZ/512;
+       do_div(x, (NSEC_PER_SEC / 512));
+#else
+       /*
+         * max relative error 5.7e-8 (1.8s per year) for AHZ <= 1024,
+         * overflow after 64.99 years.
+         * exact for AHZ=60, 72, 90, 120, 144, 180, 300, 600, 900, ...
+         */
+       x *= 9;
+       do_div(x, (unsigned long)((9ull * NSEC_PER_SEC + (AHZ/2))
+                                 / AHZ));
 #endif
-       return x;
+       return x;
 }
 
 #endif  /* __KERNEL */