On 4 Jan 2005, at 13:11, Kenneth Porter wrote:
I just saw the announcement of a new Fedora kernel with this change
note:
> A large change over previous kernels has been made. The 4G:4G memory
> split patch has been dropped, and Fedora kernels now revert back to
> the upstream 3G:1G kernel/userspace split.
A bit of googling indicates that the 4G:4G patch is needed for systems
with a lot of RAM (eg. 32 GB or more) because the kernel memory tables
scale with the size of physical memory and a 32 GB system uses 0.5 GB
for the table, half the kernel space available to a 3G:1G system. A 64
GB system won't boot because all of kernel memory is needed for the
table.
<
http://www.uwsg.iu.edu/hypermail/linux/kernel/0307.1/0246.html>
Was this reversion done for performance or for some other reason? I'd
guess most consumer systems won't need 4G:4G as they won't have
anything like that much memory, and it only makes sense for an
enterprise class server.
Maybe the 4-level Pagetable changes Andrea Arcangeli introduced into
2.6.10 are related?