VM question related to faults
xdivac02 at stud.fit.vutbr.cz
Sun Jul 30 20:04:01 UTC 2006
On Sun, Jul 30, 2006 at 12:57:32PM +0200, Divacky Roman wrote:
> while working on SoC linuxolator project I am in a need of this:
> I need to do some operation on memory like mem1 = mem1 + mem2 etc.
> where the mem1/mem2 access can trigger fault. (memory not mapped or something)
to make it clear.. I am trying to access user-space memory from kernel.
This needs to be atomic (its an implementation of linux futexes)
I need to check from kernel if some memory is accessible and then perform an
operation on this memory. All atomically.
hence I need two things - function which checks wheter the memory is accessible
and something which makes it atomic (some mutex/something which prevents other
process to enter VM to unmap/etc. the memory in question)
hope its a bit more clear now
More information about the freebsd-hackers