Hi

I am developing a bridge device driver for PCI. In my system, we will have 4GB physical memory. During my driver initialization, I need map all pci bar space to the user mode in order to access the hardware register directly from the user mode and lock 1GB user mode memory into the physical pages to ensure scatter/gather list DMA succeed all the time.

Since we all know that there are only 4GB virtual address space available, 2GB for user and 2GB for kernel. My understanding is that mapping pcibar space and lock the user memory will reserve more than 1GB virtual address space in user mode and make it unavailable for the rest of application. My question is that if there is any chance that we run out of virtual address space on Win32 OS? Since I may want to use the prelocked user memory in the kernel, is it possible to use /3GB option

Thanks

zhong