"Stephane E. Potvin" wrote: > > How often must this be allocated? > > > > How many of them are needed? > > > > If you only need a small set number of them, then they can be > > allocated very early on in the system lifetime, which means > > you should allocate them in machdep.c, with the rest of the > > memory overlay which attempts to make memory in protected mode > > look like physical RAM. > > I need one per process to hold the L1PT of the process' vm space. I will > probably implement a cache to avoid creating/destroying repetitively but I > don't think that it's reasonable to preallocate them as it will wire too > much physical memory.
So your answers are: o Allocated on every fork, freed on every exit o One per process I don't know how you have the ARM memory map laid out. One thing that FreeBSD does -- and why I suggested machdep.c -- is to map out page mappings, without providing backing store for those mappings until later. I guess I need a clarification on your original statement: > > > table of the StrongARM processor is four pages. These pages > > > need to be allocated contiguously. The questions are: o Contiguous in physical memory? yes/no o Contiguous in kernel virtual memory? yes/no o Mapped at all in user virtual memory? yes/no o Contiguous in user virtual memory? yes/no If it's just in kernel virtual memory, then the approach I suggested -- using machdep.c -- is the correct one. -- Terry To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
