On Wed, Nov 14, 2007 at 10:00:09AM +0100, Till Maas wrote: > On Mi November 14 2007, Dave Jones wrote: > > On Mon, Nov 12, 2007 at 08:08:08PM +0100, Till Maas wrote: > > > > I read > > > that the 2.6.23 kernel supports NX without the need to activate 64G > > > memory support? > > > > not true. > > Here is a kernel git changelog entry that says it is true: > > | i386: divorce CONFIG_X86_PAE from CONFIG_HIGHMEM64G > | > | PAE is useful for more than supporting more than 4GB RAM. It supports > | expanded swapspace and NX executable protections. Some users may want NX > | or expanded swapspace support without the overhead or instability of > | highmem. For these reasons, the following patch divorces CONFIG_X86_PAE > | from CONFIG_HIGHMEM64G. > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c673f1a9d994de501b674b2bb6a48bd5e912afe0 That's a really terrible exaggerated changelog entry. The 'overhead' is still there because you need to use 3-level 64bit pagetables. As for 'instability', well if there are bugs, how about we fix them? (crazy idea I know, it'll never catch on). So all this really buys you is the inability to use memory past 4G if present. For people with <4G, it's no different. They still need PAE enabled to use NX. Dave -- http://www.codemonkey.org.uk -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
