> On Mon, Jan 28, 2008 at 01:18:03AM +1100, Simon Burge wrote: > > At least MIPS and PowerPC will generate "pref" and "dcbt" instructions > > respectively that point to potentially invalid addresses with the code > > as it currently is. > > I remember some discussion of the Power4 modifications for Linux to map > NULL for the same reason. If in doubt, we can conditionalize that > statement for platforms that don't have a save prefetch. > > Joerg just FYI: http://www.kerneltraffic.org/kernel-traffic/kt20031006_234.html#3 (i don't know if __builtin_prefetch can produce the relevant instructions.) YAMAMOTO Takashi