zero huge_page can save a lot of RAM in some situations on systems that have transparent_hugepage=always.
A discussion on zero huge_page may be read at http://comments.gmane.org/gmane.linux.kernel.mm/85623
And the patch may be found at http://git.kernel.org/?p=linux/kernel/g ... 88000edc18
But the patch will be merged for Linux 3.8. Towo, would you consider backporting this patch to 3.7, or we'll just have to wait for 3.8?
It would be interesting to see how this change will affect memory usage, particularly in my system where having transparent_hugepages=always results in large RSS values for Firefox. Here's a bug report on that: https://bugzilla.mozilla.org/show_bug.cgi?id=770612