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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2013-11-14 14:31:53 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-15 09:32:20 +0900 |
| commit | ea1e7ed33708c7a760419ff9ded0a6cb90586a50 (patch) | |
| tree | 553c0c4024639bf2b1706d144fd6bb8ada63861e | |
| parent | 539edb5846c740d78a8b6c2e43a99ca4323df68f (diff) | |
| download | linux-ea1e7ed33708c7a760419ff9ded0a6cb90586a50.tar.gz linux-ea1e7ed33708c7a760419ff9ded0a6cb90586a50.tar.bz2 linux-ea1e7ed33708c7a760419ff9ded0a6cb90586a50.zip | |
mm: create a separate slab for page->ptl allocation
If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64
is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab,
so we loose 24 on each. An average system can easily allocate few tens
thousands of page->ptl and overhead is significant.
Let's create a separate slab for page->ptl allocation to solve this.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/mm.h | 9 | ||||
| -rw-r--r-- | init/main.c | 2 | ||||
| -rw-r--r-- | mm/memory.c | 7 |
3 files changed, 17 insertions, 1 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 1cedd000cf29..0548eb201e05 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1318,6 +1318,7 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a #if USE_SPLIT_PTE_PTLOCKS #if BLOATED_SPINLOCKS +void __init ptlock_cache_init(void); extern bool ptlock_alloc(struct page *page); extern void ptlock_free(struct page *page); @@ -1326,6 +1327,7 @@ static inline spinlock_t *ptlock_ptr(struct page *page) return page->ptl; } #else /* BLOATED_SPINLOCKS */ +static inline void ptlock_cache_init(void) {} static inline bool ptlock_alloc(struct page *page) { return true; @@ -1378,10 +1380,17 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd) { return &mm->page_table_lock; } +static inline void ptlock_cache_init(void) {} static inline bool ptlock_init(struct page *page) { return true; } static inline void pte_lock_deinit(struct page *page) {} #endif /* USE_SPLIT_PTE_PTLOCKS */ +static inline void pgtable_init(void) +{ + ptlock_cache_init(); + pgtable_cache_init(); +} + static inline bool pgtable_page_ctor(struct page *page) { inc_zone_page_state(page, NR_PAGETABLE); diff --git a/init/main.c b/init/main.c index 6ad1a533a8c7..5f191133376f 100644 --- a/init/main.c +++ b/init/main.c @@ -473,7 +473,7 @@ static void __init mm_init(void) mem_init(); kmem_cache_init(); percpu_init_late(); - pgtable_cache_init(); + pgtable_init(); vmalloc_init(); } diff --git a/mm/memory.c b/mm/memory.c index 5d9025f3b3e1..0409e8f43fa0 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4272,6 +4272,13 @@ void copy_user_huge_page(struct page *dst, struct page *src, #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */ #if USE_SPLIT_PTE_PTLOCKS && BLOATED_SPINLOCKS +static struct kmem_cache *page_ptl_cachep; +void __init ptlock_cache_init(void) +{ + page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(spinlock_t), 0, + SLAB_PANIC, NULL); +} + bool ptlock_alloc(struct page *page) { spinlock_t *ptl; |