Commit 485ba3c3 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds

[PATCH] rmap-5-swap_unplug-page-revert

Revert the pre-2.6.6 per-address-space unplugging changes.  This removes a
swapper_space exceptionality, syncs things with Andrea and provides for
simplification of the swap unplug function.
parent c78a6f26
......@@ -181,6 +181,8 @@ extern int vm_swappiness;
extern int shmem_unuse(swp_entry_t entry, struct page *page);
#endif /* CONFIG_MMU */
extern void swap_unplug_io_fn(struct backing_dev_info *);
#ifdef CONFIG_SWAP
/* linux/mm/page_io.c */
extern int swap_readpage(struct file *, struct page *);
......@@ -216,7 +218,7 @@ extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
extern struct swap_info_struct *get_swap_info_struct(unsigned);
extern int can_share_swap_page(struct page *);
extern int remove_exclusive_swap_page(struct page *);
extern void swap_unplug_io_fn(struct page *);
struct backing_dev_info;
extern struct swap_list_t swap_list;
extern spinlock_t swaplock;
......@@ -250,7 +252,6 @@ extern spinlock_t swaplock;
#define move_from_swap_cache(p, i, m) 1
#define __delete_from_swap_cache(p) /*NOTHING*/
#define delete_from_swap_cache(p) /*NOTHING*/
#define swap_unplug_io_fn(p) /*NOTHING*/
static inline int remove_exclusive_swap_page(struct page *p)
{
......
......@@ -127,7 +127,7 @@ static inline int sync_page(struct page *page)
if (mapping->a_ops && mapping->a_ops->sync_page)
return mapping->a_ops->sync_page(page);
} else if (PageSwapCache(page)) {
swap_unplug_io_fn(page);
swap_unplug_io_fn(NULL);
}
return 0;
}
......
......@@ -18,6 +18,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
......@@ -571,3 +572,7 @@ unsigned long get_unmapped_area(struct file *file, unsigned long addr,
void pte_chain_init(void)
{
}
void swap_unplug_io_fn(struct backing_dev_info *)
{
}
......@@ -25,13 +25,13 @@ static struct address_space_operations swap_aops = {
};
static struct backing_dev_info swap_backing_dev_info = {
.state = 0, /* uncongested */
.memory_backed = 1, /* Does not contribute to dirty memory */
.unplug_io_fn = swap_unplug_io_fn,
};
struct address_space swapper_space = {
.page_tree = RADIX_TREE_INIT(GFP_ATOMIC),
.tree_lock = SPIN_LOCK_UNLOCKED,
.nrpages = 0, /* total_swapcache_pages */
.a_ops = &swap_aops,
.backing_dev_info = &swap_backing_dev_info,
};
......
......@@ -88,26 +88,19 @@ static void remove_swap_bdev(struct block_device *bdev)
BUG();
}
/*
* Unlike a standard unplug_io_fn, swap_unplug_io_fn is never called
* through swap's backing_dev_info (which is only used by shrink_list),
* but directly from sync_page when PageSwapCache: and takes the page
* as argument, so that it can find the right device from swp_entry_t.
*/
void swap_unplug_io_fn(struct page *page)
void swap_unplug_io_fn(struct backing_dev_info *unused_bdi)
{
swp_entry_t entry;
int i;
down(&swap_bdevs_sem);
entry.val = page->private;
if (PageSwapCache(page)) {
struct block_device *bdev = swap_bdevs[swp_type(entry)];
for (i = 0; i < MAX_SWAPFILES; i++) {
struct block_device *bdev = swap_bdevs[i];
struct backing_dev_info *bdi;
if (bdev) {
bdi = bdev->bd_inode->i_mapping->backing_dev_info;
(*bdi->unplug_io_fn)(bdi);
}
if (bdev == NULL)
break;
bdi = bdev->bd_inode->i_mapping->backing_dev_info;
(*bdi->unplug_io_fn)(bdi);
}
up(&swap_bdevs_sem);
}
......
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