2007/2/25, Mansha Linux <mansha.linux@xxxxxxxxx>:
hi all, For a 32-bit machine, there is total 4GB of memory(Physiacl addresses). So in that 1 GB for Kernel and 3GB for User Space.
The kernel (on the x86 architecture, in the default configuration) splits the 4-GB *virtual address space* between user-space and the kernel; the same set of mappings is used in both contexts. A typical split dedicates 3 GB to user space, and 1 GB for kernel space.
So, kernel won't access that 3GB of memory, right? All the kernel code is exist in 1 GB of memory.... CMIIW
All the kernel code is linked using 0xC0000000(3GB, also virtual address) as the base address.
So, my doubt is the DMA(0-16MB),NORMAL(16-896MB),HIGH(896MB-) memory divided within this 4GB of memory ,right?
Within 4GB physical addresses space.
if we allocate the pages using alloc_pages, from which region the pages are allocated for the kernel modules. is it from Physical RAM memory or from 1GB of kernel space ?? From physical memory.
-- Best regards, Jarod Wang ---- Wuhan University of Technology, Wuhan, P. R. China -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
