#define __MM_INTERNAL_H
#include <linux/mm.h>
+#include <linux/rmap.h>
void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling);
extern int isolate_lru_page(struct page *page);
extern void putback_lru_page(struct page *page);
+/*
+ * in mm/rmap.c:
+ */
+extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
+
/*
* in mm/page_alloc.c
*/
{
if (TestClearPageMlocked(page)) {
unsigned long flags;
+ int nr_pages = hpage_nr_pages(page);
local_irq_save(flags);
- __dec_zone_page_state(page, NR_MLOCK);
+ __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
SetPageMlocked(newpage);
- __inc_zone_page_state(newpage, NR_MLOCK);
+ __mod_zone_page_state(page_zone(newpage), NR_MLOCK, nr_pages);
local_irq_restore(flags);
}
}
#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
#define ALLOC_CMA 0x80 /* allow allocations from CMA areas */
+/*
+ * Unnecessary readahead harms performance, especially for SSD devices, where
+ * large reads are significantly more expensive than small ones.
+ * These implements simple swap random access detection. In swap page fault: if
+ * the page is found in swapcache, decrease a counter in the vma, otherwise we
+ * need to perform sync swapin and the counter is increased. Optionally swapin
+ * will perform readahead if the counter is below a threshold.
+ */
+#ifdef CONFIG_SWAP
+#define SWAPRA_MISS_THRESHOLD (100)
+#define SWAPRA_MAX_MISS ((SWAPRA_MISS_THRESHOLD) * 10)
+static inline void swap_cache_hit(struct vm_area_struct *vma)
+{
+ if (vma && vma->anon_vma)
+ atomic_dec_if_positive(&vma->anon_vma->swapra_miss);
+}
+
+static inline void swap_cache_miss(struct vm_area_struct *vma)
+{
+ if (!vma || !vma->anon_vma)
+ return;
+ if (atomic_read(&vma->anon_vma->swapra_miss) < SWAPRA_MAX_MISS)
+ atomic_inc(&vma->anon_vma->swapra_miss);
+}
+
+static inline int swap_cache_skip_readahead(struct vm_area_struct *vma)
+{
+ if (!vma || !vma->anon_vma)
+ return 0;
+ return atomic_read(&vma->anon_vma->swapra_miss) >
+ SWAPRA_MISS_THRESHOLD;
+}
+#else
+static inline void swap_cache_hit(struct vm_area_struct *vma)
+{
+}
+
+static inline void swap_cache_miss(struct vm_area_struct *vma)
+{
+}
+
+static inline int swap_cache_skip_readahead(struct vm_area_struct *vma)
+{
+ return 0;
+}
+#endif /* CONFIG_SWAP */
+
#endif /* __MM_INTERNAL_H */