diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2013-11-14 14:31:51 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-15 09:32:20 +0900 |
| commit | 49076ec2ccaf68610aa03d96bced9a6694b93ca1 (patch) | |
| tree | 876564edb5cd164c7f9eaf39008f8f01fb164db6 /include/linux/mm_types.h | |
| parent | f820e2805c7acb157a78438d07e47f4fc57fe679 (diff) | |
mm: dynamically allocate page->ptl if it cannot be embedded to struct page
If split page table lock is in use, we embed the lock into struct page
of table's page. We have to disable split lock, if spinlock_t is too
big be to be embedded, like when DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC
enabled.
This patch add support for dynamic allocation of split page table lock
if we can't embed it to struct page.
page->ptl is unsigned long now and we use it as spinlock_t if
sizeof(spinlock_t) <= sizeof(long), otherwise it's pointer to spinlock_t.
The spinlock_t allocated in pgtable_page_ctor() for PTE table and in
pgtable_pmd_page_ctor() for PMD table. All other helpers converted to
support dynamically allocated page->ptl.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mm_types.h')
| -rw-r--r-- | include/linux/mm_types.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 934261099975..423da79877e6 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -147,7 +147,10 @@ struct page { * system if PG_buddy is set. */ #if USE_SPLIT_PTE_PTLOCKS - spinlock_t ptl; + unsigned long ptl; /* It's spinlock_t if it fits to long, + * otherwise it's pointer to dynamicaly + * allocated spinlock_t. + */ #endif struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */ struct page *first_page; /* Compound tail pages */ |