109 lines
2.8 KiB
C
109 lines
2.8 KiB
C
#ifndef __LINUX_KSM_H
|
|
#define __LINUX_KSM_H
|
|
/*
|
|
* Memory merging support.
|
|
*
|
|
* This code enables dynamic sharing of identical pages found in different
|
|
* memory areas, even if they are not shared by fork().
|
|
*/
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/rmap.h>
|
|
#include <linux/sched.h>
|
|
|
|
struct stable_node;
|
|
struct mem_cgroup;
|
|
|
|
#ifdef CONFIG_KSM
|
|
int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end, int advice, unsigned long *vm_flags);
|
|
int __ksm_enter(struct mm_struct *mm);
|
|
void __ksm_exit(struct mm_struct *mm);
|
|
|
|
static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
|
|
{
|
|
if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags))
|
|
return __ksm_enter(mm);
|
|
return 0;
|
|
}
|
|
|
|
static inline void ksm_exit(struct mm_struct *mm)
|
|
{
|
|
if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
|
|
__ksm_exit(mm);
|
|
}
|
|
|
|
static inline struct stable_node *page_stable_node(struct page *page)
|
|
{
|
|
return PageKsm(page) ? page_rmapping(page) : NULL;
|
|
}
|
|
|
|
static inline void set_page_stable_node(struct page *page,
|
|
struct stable_node *stable_node)
|
|
{
|
|
page->mapping = (void *)((unsigned long)stable_node | PAGE_MAPPING_KSM);
|
|
}
|
|
|
|
/*
|
|
* When do_swap_page() first faults in from swap what used to be a KSM page,
|
|
* no problem, it will be assigned to this vma's anon_vma; but thereafter,
|
|
* it might be faulted into a different anon_vma (or perhaps to a different
|
|
* offset in the same anon_vma). do_swap_page() cannot do all the locking
|
|
* needed to reconstitute a cross-anon_vma KSM page: for now it has to make
|
|
* a copy, and leave remerging the pages to a later pass of ksmd.
|
|
*
|
|
* We'd like to make this conditional on vma->vm_flags & VM_MERGEABLE,
|
|
* but what if the vma was unmerged while the page was swapped out?
|
|
*/
|
|
struct page *ksm_might_need_to_copy(struct page *page,
|
|
struct vm_area_struct *vma, unsigned long address);
|
|
|
|
int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
|
|
void ksm_migrate_page(struct page *newpage, struct page *oldpage);
|
|
|
|
#else /* !CONFIG_KSM */
|
|
|
|
static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void ksm_exit(struct mm_struct *mm)
|
|
{
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
static inline int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end, int advice, unsigned long *vm_flags)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline struct page *ksm_might_need_to_copy(struct page *page,
|
|
struct vm_area_struct *vma, unsigned long address)
|
|
{
|
|
return page;
|
|
}
|
|
|
|
static inline int page_referenced_ksm(struct page *page,
|
|
struct mem_cgroup *memcg, unsigned long *vm_flags)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int rmap_walk_ksm(struct page *page,
|
|
struct rmap_walk_control *rwc)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void ksm_migrate_page(struct page *newpage, struct page *oldpage)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
#endif /* !CONFIG_KSM */
|
|
|
|
#endif /* __LINUX_KSM_H */
|