diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2013-11-14 14:31:52 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-15 09:32:20 +0900 |
| commit | 539edb5846c740d78a8b6c2e43a99ca4323df68f (patch) | |
| tree | dd03e1a7149f101f42311eac41e2857816cce36c /include/linux | |
| parent | 49076ec2ccaf68610aa03d96bced9a6694b93ca1 (diff) | |
| download | lwn-539edb5846c740d78a8b6c2e43a99ca4323df68f.tar.gz lwn-539edb5846c740d78a8b6c2e43a99ca4323df68f.zip | |
mm: properly separate the bloated ptl from the regular case
Use kernel/bounds.c to convert build-time spinlock_t size check into a
preprocessor symbol and apply that to properly separate the page::ptl
situation.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 24 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 9 |
2 files changed, 18 insertions, 15 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index d0339741b6ce..1cedd000cf29 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1317,27 +1317,29 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a #endif /* CONFIG_MMU && !__ARCH_HAS_4LEVEL_HACK */ #if USE_SPLIT_PTE_PTLOCKS -bool __ptlock_alloc(struct page *page); -void __ptlock_free(struct page *page); +#if BLOATED_SPINLOCKS +extern bool ptlock_alloc(struct page *page); +extern void ptlock_free(struct page *page); + +static inline spinlock_t *ptlock_ptr(struct page *page) +{ + return page->ptl; +} +#else /* BLOATED_SPINLOCKS */ static inline bool ptlock_alloc(struct page *page) { - if (sizeof(spinlock_t) > sizeof(page->ptl)) - return __ptlock_alloc(page); return true; } + static inline void ptlock_free(struct page *page) { - if (sizeof(spinlock_t) > sizeof(page->ptl)) - __ptlock_free(page); } static inline spinlock_t *ptlock_ptr(struct page *page) { - if (sizeof(spinlock_t) > sizeof(page->ptl)) - return (spinlock_t *) page->ptl; - else - return (spinlock_t *) &page->ptl; + return &page->ptl; } +#endif /* BLOATED_SPINLOCKS */ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd) { @@ -1354,7 +1356,7 @@ static inline bool ptlock_init(struct page *page) * slab code uses page->slab_cache and page->first_page (for tail * pages), which share storage with page->ptl. */ - VM_BUG_ON(page->ptl); + VM_BUG_ON(*(unsigned long *)&page->ptl); if (!ptlock_alloc(page)) return false; spin_lock_init(ptlock_ptr(page)); diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 423da79877e6..10f5a7272b80 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -147,10 +147,11 @@ struct page { * system if PG_buddy is set. */ #if USE_SPLIT_PTE_PTLOCKS - unsigned long ptl; /* It's spinlock_t if it fits to long, - * otherwise it's pointer to dynamicaly - * allocated spinlock_t. - */ +#if BLOATED_SPINLOCKS + spinlock_t *ptl; +#else + spinlock_t ptl; +#endif #endif struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */ struct page *first_page; /* Compound tail pages */ |