From e496cf3d782135c1cca0d154d4b924517ff58de0 Mon Sep 17 00:00:00 2001 From: Kirill A. Shutemov Date: Tue, 26 Jul 2016 15:26:35 -0700 Subject: thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE For file mappings, we don't deposit page tables on THP allocation because it's not strictly required to implement split_huge_pmd(): we can just clear pmd and let following page faults to reconstruct the page table. But Power makes use of deposited page table to address MMU quirk. Let's hide THP page cache, including huge tmpfs, under separate config option, so it can be forbidden on Power. We can revert the patch later once solution for Power found. Link: http://lkml.kernel.org/r/1466021202-61880-36-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Cc: Aneesh Kumar K.V Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/Kconfig | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'mm/Kconfig') diff --git a/mm/Kconfig b/mm/Kconfig index 3e2daef3c946..3c81803b00a3 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -439,6 +439,14 @@ choice benefit. endchoice +# +# We don't deposit page tables on file THP mapping, +# but Power makes use of them to address MMU quirk. +# +config TRANSPARENT_HUGE_PAGECACHE + def_bool y + depends on TRANSPARENT_HUGEPAGE && !PPC + # # UP and nommu archs use km based percpu allocator # -- cgit v1.2.3-55-g7522