diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-07-26 15:26:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-26 16:19:19 -0700 |
| commit | e496cf3d782135c1cca0d154d4b924517ff58de0 (patch) | |
| tree | 884ae0082c0b344dd9200b28ca087a3cc0973fed /include/linux/shmem_fs.h | |
| parent | f3f0e1d2150b2b99da2cbdfaad000089efe9bf30 (diff) | |
| download | linux-0-day-e496cf3d782135c1cca0d154d4b924517ff58de0.tar.gz linux-0-day-e496cf3d782135c1cca0d154d4b924517ff58de0.tar.xz | |
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 <kirill.shutemov@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/shmem_fs.h')
| -rw-r--r-- | include/linux/shmem_fs.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 0890f700a5465..54fa28dfbd89d 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -54,7 +54,6 @@ extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags); extern int shmem_lock(struct file *file, int lock, struct user_struct *user); extern bool shmem_mapping(struct address_space *mapping); -extern bool shmem_huge_enabled(struct vm_area_struct *vma); extern void shmem_unlock_mapping(struct address_space *mapping); extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, pgoff_t index, gfp_t gfp_mask); @@ -112,4 +111,13 @@ static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a) #endif +#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE +extern bool shmem_huge_enabled(struct vm_area_struct *vma); +#else +static inline bool shmem_huge_enabled(struct vm_area_struct *vma) +{ + return false; +} +#endif + #endif |