On 9/3/05, Raghu Vadapalli <iprsvp@xxxxxxxxx> wrote: > Does it mean that if I have RAM > 1GB on my m/c it's not of any use ? > Can somebody please clarify. or Only kernel space code + data can't > be more than 1GB ?. User space can always get the rest of the RAM ? > No, The Kernel Space uses all the physical RAM available on the System and that is upto 64GB on the x86 Architecture ..... The 0 to 896MB RAM is directly mapped by the kernel and the above 896MB RAM is accesses through creating temporary mappings with-in its 1G of Vitual Address Space. This 3G/1G things are for the Virtual Addresses that a processor can access through its 32bit-registers and the 1G for kernel is actually mapped to 0 to 896MB of physical memory. And user 3G Virtual Address is not directly mapped to physical memory. User Space also uses physical memory, but user space memory is subject to be swapped out but kernel won't. So Kernel will use all available physical memory always and user space gets the memory when needed ....... -- Fawad Lateef -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
