linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Memory Migration functionality - linux/mm/migrate.c

 *

 * Copyright (C) 2006 Silicon Graphics, Inc., Christoph Lameter

 *

 * Page migration was first developed in the context of the memory hotplug

 * project. The main authors of the migration code are:

 *

 * IWAMOTO Toshihiro <iwamoto@valinux.co.jp>

 * Hirokazu Takahashi <taka@valinux.co.jp>

 * Dave Hansen <haveblue@us.ibm.com>

 * Christoph Lameter

 */

​

#include <linux/migrate.h>

#include <linux/export.h>

#include <linux/swap.h>

#include <linux/swapops.h>

#include <linux/pagemap.h>

#include <linux/buffer_head.h>

#include <linux/mm_inline.h>

#include <linux/nsproxy.h>

#include <linux/pagevec.h>

#include <linux/ksm.h>

#include <linux/rmap.h>

#include <linux/topology.h>

#include <linux/cpu.h>

#include <linux/cpuset.h>

#include <linux/writeback.h>

#include <linux/mempolicy.h>

#include <linux/vmalloc.h>

#include <linux/security.h>

#include <linux/backing-dev.h>

#include <linux/compaction.h>

#include <linux/syscalls.h>

#include <linux/compat.h>

#include <linux/hugetlb.h>

#include <linux/hugetlb_cgroup.h>

#include <linux/gfp.h>

#include <linux/pfn_t.h>

#include <linux/memremap.h>

#include <linux/userfaultfd_k.h>

#include <linux/balloon_compaction.h>

#include <linux/mmu_notifier.h>

#include <linux/page_idle.h>

#include <linux/page_owner.h>

#include <linux/sched/mm.h>

#include <linux/ptrace.h>

​

#include <asm/tlbflush.h>

​

#define CREATE_TRACE_POINTS

#include <trace/events/migrate.h>

​

#include "internal.h"

​

/*

 * migrate_prep() needs to be called before we start compiling a list of pages

 * to be migrated using isolate_lru_page(). If scheduling work on other CPUs is

 * undesirable, use migrate_prep_local()

 */

int migrate_prep(void)

{

    /*

     * Clear the LRU lists so pages can be isolated.

     * Note that pages may be moved off the LRU after we have

     * drained them. Those pages will fail to migrate like other

     * pages that may be busy.

     */

    lru_add_drain_all();

​

    return 0;

}

​

/* Do the necessary work of migrate_prep but not if it involves other CPUs */

int migrate_prep_local(void)

{

    lru_add_drain();

​

    return 0;

}

​

int isolate_movable_page(struct page *page, isolate_mode_t mode)

{

    struct address_space *mapping;

​

    /*

     * Avoid burning cycles with pages that are yet under __free_pages(),

     * or just got freed under us.

     *

     * In case we 'win' a race for a movable page being freed under us and