Current File : //usr/lib/modules/3.10.0-957.21.3.el7.centos.plus.x86_64/source/arch/x86/include/asm/mm_track.h
/*
* Routines and structures for building a bitmap of
* dirty pages in a live system. For use in memory mirroring
* or migration applications.
*
* Copyright (C) 2006, 2010 Stratus Technologies Bermuda Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef __X86_64_MMTRACK_H__
#define __X86_64_MMTRACK_H__
#ifndef CONFIG_TRACK_DIRTY_PAGES
static inline void mm_track_pte(pte_t *ptep) {}
static inline void mm_track_pmd(pmd_t *pmdp) {}
static inline void mm_track_pud(pud_t *pudp) {}
static inline void mm_track_pgd(pgd_t *pgdp) {}
static inline void mm_track_phys(void *physp) {}
static inline int harvest_user(void) { return 0; }
#else
#include <asm/page.h>
#include <asm/atomic.h>
#include <linux/static_key.h>
/*
* For memory-tracking purposes, if active is enabled, the other
* elements of the structure are available for use. Each time mm_track_pte
* is called, it increments count and sets a bit in the bitvector table.
* Each bit in the bitvector represents a physical page in memory.
*
* This is declared in arch/x86_64/mm/track.c.
*
* The in_use element is used in the code which drives the memory tracking
* environment. When tracking is complete, the vector may be freed, but
* only after the active key is disabled and the in_use count goes to
* zero.
*
* The count element indicates how many pages have been stored in the
* bitvector. This is an optimization to avoid counting the bits in the
* vector between harvest operations.
*/
struct mm_tracker {
struct static_key active; /* TRUE if this structure is in use */
atomic_t count; /* number of pages tracked by mm_track() */
unsigned long *vector; /* bit vector of modified pages */
unsigned long bitcnt; /* number of bits in vector */
};
extern struct mm_tracker mm_tracking_struct;
extern int mm_track_init(long);
extern void mm_track_exit(void);
extern void do_mm_track_pte(void *);
extern void do_mm_track_pmd(void *);
extern void do_mm_track_pud(void *);
extern void do_mm_track_pgd(void *);
extern void do_mm_track_phys(void *);
extern int harvest_user(void);
/*
* The mm_track routine is needed by macros in pgtable.h
*/
static inline void mm_track_pte(pte_t *ptep)
{
if (static_key_false(&mm_tracking_struct.active))
do_mm_track_pte(ptep);
}
static inline void mm_track_pmd(pmd_t *pmdp)
{
if (static_key_false(&mm_tracking_struct.active))
do_mm_track_pmd(pmdp);
}
static inline void mm_track_pud(pud_t *pudp)
{
if (static_key_false(&mm_tracking_struct.active))
do_mm_track_pud(pudp);
}
static inline void mm_track_pgd(pgd_t *pgdp)
{
if (static_key_false(&mm_tracking_struct.active))
do_mm_track_pgd(pgdp);
}
static inline void mm_track_phys(void *physp)
{
if (static_key_false(&mm_tracking_struct.active))
do_mm_track_phys(physp);
}
#endif /* CONFIG_TRACK_DIRTY_PAGES */
#endif /* __X86_64_MMTRACK_H__ */
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