linux-imx

/*

 * mm/page-writeback.c

 *

 * Copyright (C) 2002, Linus Torvalds.

 * Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra

 *

 * Contains functions related to writing back dirty pages at the

 * address_space level.

 *

 * 10Apr2002    Andrew Morton

 *      Initial version

 */

​

#include <linux/kernel.h>

#include <linux/export.h>

#include <linux/spinlock.h>

#include <linux/fs.h>

#include <linux/mm.h>

#include <linux/swap.h>

#include <linux/slab.h>

#include <linux/pagemap.h>

#include <linux/writeback.h>

#include <linux/init.h>

#include <linux/backing-dev.h>

#include <linux/task_io_accounting_ops.h>

#include <linux/blkdev.h>

#include <linux/mpage.h>

#include <linux/rmap.h>

#include <linux/percpu.h>

#include <linux/smp.h>

#include <linux/sysctl.h>

#include <linux/cpu.h>

#include <linux/syscalls.h>

#include <linux/buffer_head.h> /* __set_page_dirty_buffers */

#include <linux/pagevec.h>

#include <linux/timer.h>

#include <linux/sched/rt.h>

#include <linux/sched/signal.h>

#include <linux/mm_inline.h>

#include <trace/events/writeback.h>

​

#include "internal.h"

​

/*

 * Sleep at most 200ms at a time in balance_dirty_pages().

 */

#define MAX_PAUSE       max(HZ/5, 1)

​

/*

 * Try to keep balance_dirty_pages() call intervals higher than this many pages

 * by raising pause time to max_pause when falls below it.

 */

#define DIRTY_POLL_THRESH   (128 >> (PAGE_SHIFT - 10))

​

/*

 * Estimate write bandwidth at 200ms intervals.

 */

#define BANDWIDTH_INTERVAL  max(HZ/5, 1)

​

#define RATELIMIT_CALC_SHIFT    10

​

/*

 * After a CPU has dirtied this many pages, balance_dirty_pages_ratelimited