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Commit a913e182 authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

ksm: clean up obsolete references 



A few cleanups, given the munlock fix: the comment on ksm_test_exit() no
longer applies, and it can be made private to ksm.c; there's no more
reference to mmu_gather or tlb.h, and mmap.c doesn't need ksm.h.

Signed-off-by: default avatarHugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: default avatarIzik Eidus <ieidus@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8314c4f2

include/linux/ksm.h

+0 −20
Original line number Diff line number Diff line
@@ -12,8 +12,6 @@ 
#include <linux/sched.h>

#include <linux/vmstat.h>



struct mmu_gather;



#ifdef CONFIG_KSM

int ksm_madvise(struct vm_area_struct *vma, unsigned long start,

		unsigned long end, int advice, unsigned long *vm_flags);
@@ -27,19 +25,6 @@ static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) 
	return 0;

}



/*

 * For KSM to handle OOM without deadlock when it's breaking COW in a

 * likely victim of the OOM killer, exit_mmap() has to serialize with

 * ksm_exit() after freeing mm's pages but before freeing its page tables.

 * That leaves a window in which KSM might refault pages which have just

 * been finally unmapped: guard against that with ksm_test_exit(), and

 * use it after getting mmap_sem in ksm.c, to check if mm is exiting.

 */

static inline bool ksm_test_exit(struct mm_struct *mm)

{

	return atomic_read(&mm->mm_users) == 0;

}



static inline void ksm_exit(struct mm_struct *mm)

{

	if (test_bit(MMF_VM_MERGEABLE, &mm->flags))
@@ -79,11 +64,6 @@ static inline int ksm_fork(struct mm_struct *mm, struct mm_struct *oldmm) 
	return 0;

}



static inline bool ksm_test_exit(struct mm_struct *mm)

{

	return 0;

}



static inline void ksm_exit(struct mm_struct *mm)

{

}

mm/ksm.c

+13 −1
Original line number Diff line number Diff line
@@ -32,7 +32,6 @@ 
#include <linux/mmu_notifier.h>

#include <linux/ksm.h>



#include <asm/tlb.h>

#include <asm/tlbflush.h>



/*
@@ -284,6 +283,19 @@ static inline int in_stable_tree(struct rmap_item *rmap_item) 
	return rmap_item->address & STABLE_FLAG;

}



/*

 * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's

 * page tables after it has passed through ksm_exit() - which, if necessary,

 * takes mmap_sem briefly to serialize against them.  ksm_exit() does not set

 * a special flag: they can just back out as soon as mm_users goes to zero.

 * ksm_test_exit() is used throughout to make this test for exit: in some

 * places for correctness, in some places just to avoid unnecessary work.

 */

static inline bool ksm_test_exit(struct mm_struct *mm)

{

	return atomic_read(&mm->mm_users) == 0;

}



/*

 * We use break_ksm to break COW on a ksm page: it's a stripped down

 *

mm/mmap.c

+0 −1
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ 
#include <linux/mount.h>

#include <linux/mempolicy.h>

#include <linux/rmap.h>

#include <linux/ksm.h>

#include <linux/mmu_notifier.h>

#include <linux/perf_event.h>