Re: [PATCH -V5 06/25] powerpc: Reduce PTE table memory wastage

"Aneesh Kumar K.V" [off-list ref] writes:

Michael Ellerman [off-list ref] writes:

quoted

On Thu, Apr 04, 2013 at 11:27:44AM +0530, Aneesh Kumar K.V wrote:

quoted

From: "Aneesh Kumar K.V" <redacted>

We allocate one page for the last level of linux page table. With THP and
large page size of 16MB, that would mean we are wasting large part
of that page. To map 16MB area, we only need a PTE space of 2K with 64K
page size. This patch reduce the space wastage by sharing the page
allocated for the last level of linux page table with multiple pmd
entries. We call these smaller chunks PTE page fragments and allocated
page, PTE page.

This is not compiling for me:

arch/powerpc/mm/mmu_context_hash64.c:118:3: error: implicit declaration of function 'reset_page_mapcount'

can you share the .config ? I have the git tree at 

git://github.com/kvaneesh/linux.git ppc64-thp-7

22b751c3d0376e86a377e3a0aa2ddbbe9d2eefc1 . Will rebase to latest linus tree.

-aneesh