mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 18:39:59 +00:00
2c281f54f5
Let's factor out actual disabling of KSM. The existing "mm->def_flags &= ~VM_MERGEABLE;" was essentially a NOP and can be dropped, because def_flags should never include VM_MERGEABLE. Note that we don't currently prevent re-enabling KSM. This should now be faster in case KSM was never enabled, because we only conditionally iterate all VMAs. Further, it certainly looks cleaner. Link: https://lkml.kernel.org/r/20230422210156.33630-1-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Janosch Frank <frankja@linux.ibm.com> Acked-by: Stefan Roesch <shr@devkernel.io> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Rik van Riel <riel@surriel.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
129 lines
3.2 KiB
C
129 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#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>
|
|
#include <linux/sched/coredump.h>
|
|
|
|
#ifdef CONFIG_KSM
|
|
int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end, int advice, unsigned long *vm_flags);
|
|
|
|
void ksm_add_vma(struct vm_area_struct *vma);
|
|
int ksm_enable_merge_any(struct mm_struct *mm);
|
|
int ksm_disable_merge_any(struct mm_struct *mm);
|
|
int ksm_disable(struct mm_struct *mm);
|
|
|
|
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)
|
|
{
|
|
int ret;
|
|
|
|
if (test_bit(MMF_VM_MERGEABLE, &oldmm->flags)) {
|
|
ret = __ksm_enter(mm);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
if (test_bit(MMF_VM_MERGE_ANY, &oldmm->flags))
|
|
set_bit(MMF_VM_MERGE_ANY, &mm->flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline void ksm_exit(struct mm_struct *mm)
|
|
{
|
|
if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
|
|
__ksm_exit(mm);
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
|
|
void rmap_walk_ksm(struct folio *folio, struct rmap_walk_control *rwc);
|
|
void folio_migrate_ksm(struct folio *newfolio, struct folio *folio);
|
|
|
|
#ifdef CONFIG_MEMORY_FAILURE
|
|
void collect_procs_ksm(struct page *page, struct list_head *to_kill,
|
|
int force_early);
|
|
#endif
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
long ksm_process_profit(struct mm_struct *);
|
|
#endif /* CONFIG_PROC_FS */
|
|
|
|
#else /* !CONFIG_KSM */
|
|
|
|
static inline void ksm_add_vma(struct vm_area_struct *vma)
|
|
{
|
|
}
|
|
|
|
static inline int ksm_disable(struct mm_struct *mm)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
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_MEMORY_FAILURE
|
|
static inline void collect_procs_ksm(struct page *page,
|
|
struct list_head *to_kill, int force_early)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#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 void rmap_walk_ksm(struct folio *folio,
|
|
struct rmap_walk_control *rwc)
|
|
{
|
|
}
|
|
|
|
static inline void folio_migrate_ksm(struct folio *newfolio, struct folio *old)
|
|
{
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
#endif /* !CONFIG_KSM */
|
|
|
|
#endif /* __LINUX_KSM_H */
|