vanilla kernel 2.4.17: [see below for ingo's patch results]
*****************************************
Process fork+exit: 171.0303 microseconds 
Process fork+execve: 1582.7500 microseconds 
Process fork+/bin/sh -c: 7813.0000 microseconds 

Process fork+exit: 172.7500 microseconds 
Process fork+execve: 1567.0000 microseconds 
Process fork+/bin/sh -c: 7795.0000 microseconds 

Process fork+exit: 171.7812 microseconds 
Process fork+execve: 1580.2500 microseconds 
Process fork+/bin/sh -c: 7810.0000 microseconds 

Process fork+exit: 177.9062 microseconds 
Process fork+execve: 1592.7500 microseconds 
Process fork+/bin/sh -c: 7781.0000 microseconds 

Process fork+exit: 175.7188 microseconds 
Process fork+execve: 1602.2500 microseconds 
Process fork+/bin/sh -c: 7800.0000 microseconds 

Process fork+exit: 180.5667 microseconds 
Process fork+execve: 1567.5000 microseconds 
Process fork+/bin/sh -c: 7789.0000 microseconds 

Process fork+exit: 183.7000 microseconds 
Process fork+execve: 1580.2500 microseconds 
Process fork+/bin/sh -c: 7812.0000 microseconds 

Process fork+exit: 179.5333 microseconds 
Process fork+execve: 1578.5000 microseconds 
Process fork+/bin/sh -c: 7833.0000 microseconds 

Process fork+exit: 180.6000 microseconds 
Process fork+execve: 1582.2500 microseconds 
Process fork+/bin/sh -c: 7801.0000 microseconds 

Process fork+exit: 181.1935 microseconds 
Process fork+execve: 1570.5000 microseconds 
Process fork+/bin/sh -c: 7789.0000 microseconds 

Process fork+exit: 182.5000 microseconds 
Process fork+execve: 1588.7500 microseconds 
Process fork+/bin/sh -c: 7824.0000 microseconds 

Process fork+exit: 185.3333 microseconds 
Process fork+execve: 1590.7500 microseconds 
Process fork+/bin/sh -c: 7815.0000 microseconds 

Process fork+exit: 181.4667 microseconds 
Process fork+execve: 1580.2500 microseconds 
Process fork+/bin/sh -c: 7831.0000 microseconds 

Process fork+exit: 183.7333 microseconds 
Process fork+execve: 1569.2500 microseconds 
Process fork+/bin/sh -c: 7829.0000 microseconds 

Process fork+exit: 177.3548 microseconds 
Process fork+execve: 1592.2500 microseconds 
Process fork+/bin/sh -c: 7827.0000 microseconds 

Process fork+exit: 178.7812 microseconds 
Process fork+execve: 1598.2500 microseconds 
Process fork+/bin/sh -c: 7810.0000 microseconds 

**********************************************
ingo molnar patch applied kernel :

Process fork+exit: 193.1071 microseconds 
Process fork+execve: 1658.5000 microseconds 
Process fork+/bin/sh -c: 7994.0000 microseconds 

Process fork+exit: 187.8276 microseconds 
Process fork+execve: 1657.0000 microseconds 
Process fork+/bin/sh -c: 7983.0000 microseconds 

Process fork+exit: 206.2222 microseconds 
Process fork+execve: 1672.7500 microseconds 
Process fork+/bin/sh -c: 7960.0000 microseconds 

Process fork+exit: 193.5000 microseconds 
Process fork+execve: 1677.0000 microseconds 
Process fork+/bin/sh -c: 7986.0000 microseconds 

Process fork+exit: 205.0000 microseconds 
Process fork+execve: 1675.7500 microseconds 
Process fork+/bin/sh -c: 7977.0000 microseconds 

Process fork+exit: 200.7407 microseconds 
Process fork+execve: 1665.2500 microseconds 
Process fork+/bin/sh -c: 7976.0000 microseconds 

Process fork+exit: 190.2069 microseconds 
Process fork+execve: 1662.2500 microseconds 
Process fork+/bin/sh -c: 7991.0000 microseconds 

Process fork+exit: 193.7586 microseconds 
Process fork+execve: 1661.5000 microseconds 
Process fork+/bin/sh -c: 7992.0000 microseconds 

Process fork+exit: 199.5000 microseconds 
Process fork+execve: 1680.7500 microseconds 
Process fork+/bin/sh -c: 7965.0000 microseconds 

Process fork+exit: 200.3214 microseconds 
Process fork+execve: 1662.2500 microseconds 
Process fork+/bin/sh -c: 7983.0000 microseconds 

Process fork+exit: 188.1724 microseconds 
Process fork+execve: 1650.7500 microseconds 
Process fork+/bin/sh -c: 7987.0000 microseconds 

Process fork+exit: 199.7143 microseconds 
Process fork+execve: 1645.7500 microseconds 
Process fork+/bin/sh -c: 8075.0000 microseconds 

Process fork+exit: 207.3704 microseconds 
Process fork+execve: 1645.7500 microseconds 
Process fork+/bin/sh -c: 8034.0000 microseconds 

Process fork+exit: 213.0357 microseconds 
Process fork+execve: 1660.0000 microseconds 
Process fork+/bin/sh -c: 8004.0000 microseconds 

Process fork+exit: 202.3929 microseconds 
Process fork+execve: 1649.0000 microseconds 
Process fork+/bin/sh -c: 7979.0000 microseconds 

Process fork+exit: 197.3929 microseconds 
Process fork+execve: 1744.5000 microseconds 
Process fork+/bin/sh -c: 7972.0000 microseconds 

Process fork+exit: 209.5000 microseconds 
Process fork+execve: 1644.0000 microseconds 
Process fork+/bin/sh -c: 7980.0000 microseconds 

Process fork+exit: 208.7308 microseconds 
Process fork+execve: 1644.7500 microseconds 
Process fork+/bin/sh -c: 7994.0000 microseconds 

Process fork+exit: 206.4815 microseconds 
Process fork+execve: 1654.2500 microseconds 
Process fork+/bin/sh -c: 8003.0000 microseconds 

Process fork+exit: 197.4643 microseconds 
Process fork+execve: 1645.7500 microseconds 
Process fork+/bin/sh -c: 7989.0000 microseconds 

Process fork+exit: 210.6154 microseconds 
Process fork+execve: 1645.7500 microseconds 
Process fork+/bin/sh -c: 8014.0000 microseconds 

Process fork+exit: 190.1034 microseconds 
Process fork+execve: 1637.2500 microseconds 
Process fork+/bin/sh -c: 8023.0000 microseconds