On Thu, Jan 27, 2005, Jacques Fourie wrote: > Hi, > > Yes, I am trying to patch a piece of code in the kernel. The strange > thing is that this code works without a problem on FreeBSD 4.8 - has > the VM system changed to such an extent between 4.8 and 4.9 that the > pages in the kernel code segment are not writeable anymore? > > Thanks for the bit about the compiler optimization - at least I > understand that part now :)
The idea that the compiler is responsible for the different behavior between 4.8 and 4.9 is just a theory, but it really doesn't matter; it's not so easy to dynamically change the code for a function. In addition to the protection bits, you also have to worry about synchronization with calls to that function, and about the possibility that a processor may have the old code in its instruction cache. _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
