On 11/24/10 11:06 PM, cpolish@surewest.net wrote:
http://www.centos.org/docs/4/html/release-notes/as-x86/ Red Hat Enterprise Linux 4 includes a kernel known as the hugemem kernel. This kernel supports a 4GB per-process user space (versus 3GB for the other kernels), and a 4GB direct kernel space. Using this kernel allows Red Hat Enterprise Linux to run on systems with up to 64GB of main memory. The hugemem kernel is required in order to use all the memory in system configurations containing more than 16GB of memory. The hugemem kernel can also benefit configurations running with less memory (if running an application that could benefit from the larger per-process user space, for example.)
that kernel will also greatly increase overhead of all system calls as they will require pagetable swaps on every transition from user -> kernel and back, and any arguments to kernel calls will have to be copied to a static shared buffer (and results copied back). large arguments will be particularlly ugly.