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authorPeter Zijlstra <peterz@infradead.org>2013-11-14 14:31:52 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-15 09:32:20 +0900
commit539edb5846c740d78a8b6c2e43a99ca4323df68f (patch)
treedd03e1a7149f101f42311eac41e2857816cce36c /include
parent49076ec2ccaf68610aa03d96bced9a6694b93ca1 (diff)
downloadlinux-0-day-539edb5846c740d78a8b6c2e43a99ca4323df68f.tar.gz
linux-0-day-539edb5846c740d78a8b6c2e43a99ca4323df68f.tar.xz
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')
-rw-r--r--include/linux/mm.h24
-rw-r--r--include/linux/mm_types.h9
2 files changed, 18 insertions, 15 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index d0339741b6cee..1cedd000cf293 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 423da79877e6a..10f5a7272b804 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 */