[XFS] use pagevec lookups This reduces the time spend in the radix tree

[firefly-linux-kernel-4.4.55.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 510f0039b00030a7867d38be885f87afcdd76c4f..6544565a7c0f6de28879dcee44e6fcb63c2a2659 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -36,8 +36,6 @@ unsigned int nr_swapfiles;
 long total_swap_pages;
 static int swap_overflow;
 
-EXPORT_SYMBOL(total_swap_pages);
-
 static const char Bad_file[] = "Bad swap file entry ";
 static const char Unused_file[] = "Unused swap file entry ";
 static const char Bad_offset[] = "Bad swap offset entry ";
@@ -61,7 +59,7 @@ void swap_unplug_io_fn(struct backing_dev_info *unused_bdi, struct page *page)
        swp_entry_t entry;
 
        down_read(&swap_unplug_sem);
-       entry.val = page->private;
+       entry.val = page_private(page);
        if (PageSwapCache(page)) {
                struct block_device *bdev = swap_info[swp_type(entry)].bdev;
                struct backing_dev_info *bdi;
@@ -69,8 +67,8 @@ void swap_unplug_io_fn(struct backing_dev_info *unused_bdi, struct page *page)
                /*
                 * If the page is removed from swapcache from under us (with a
                 * racy try_to_unuse/swapoff) we need an additional reference
-                * count to avoid reading garbage from page->private above. If
-                * the WARN_ON triggers during a swapoff it maybe the race
+                * count to avoid reading garbage from page_private(page) above.
+                * If the WARN_ON triggers during a swapoff it maybe the race
                 * condition and it's harmless. However if it triggers without
                 * swapoff it signals a problem.
                 */
@@ -213,6 +211,26 @@ noswap:
        return (swp_entry_t) {0};
 }
 
+swp_entry_t get_swap_page_of_type(int type)
+{
+       struct swap_info_struct *si;
+       pgoff_t offset;
+
+       spin_lock(&swap_lock);
+       si = swap_info + type;
+       if (si->flags & SWP_WRITEOK) {
+               nr_swap_pages--;
+               offset = scan_swap_map(si);
+               if (offset) {
+                       spin_unlock(&swap_lock);
+                       return swp_entry(type, offset);
+               }
+               nr_swap_pages++;
+       }
+       spin_unlock(&swap_lock);
+       return (swp_entry_t) {0};
+}
+
 static struct swap_info_struct * swap_info_get(swp_entry_t entry)
 {
        struct swap_info_struct * p;
@@ -294,7 +312,7 @@ static inline int page_swapcount(struct page *page)
        struct swap_info_struct *p;
        swp_entry_t entry;
 
-       entry.val = page->private;
+       entry.val = page_private(page);
        p = swap_info_get(entry);
        if (p) {
                /* Subtract the 1 for the swap cache itself */
@@ -339,7 +357,7 @@ int remove_exclusive_swap_page(struct page *page)
        if (page_count(page) != 2) /* 2: us + cache */
                return 0;
 
-       entry.val = page->private;
+       entry.val = page_private(page);
        p = swap_info_get(entry);
        if (!p)
                return 0;
@@ -1042,7 +1060,7 @@ int page_queue_congested(struct page *page)
        BUG_ON(!PageLocked(page));      /* It pins the swap_info_struct */
 
        if (PageSwapCache(page)) {
-               swp_entry_t entry = { .val = page->private };
+               swp_entry_t entry = { .val = page_private(page) };
                struct swap_info_struct *sis;
 
                sis = get_swap_info_struct(swp_type(entry));
@@ -1169,9 +1187,9 @@ asmlinkage long sys_swapoff(const char __user * specialfile)
                set_blocksize(bdev, p->old_block_size);
                bd_release(bdev);
        } else {
-               down(&inode->i_sem);
+               mutex_lock(&inode->i_mutex);
                inode->i_flags &= ~S_SWAPFILE;
-               up(&inode->i_sem);
+               mutex_unlock(&inode->i_mutex);
        }
        filp_close(swap_file, NULL);
        err = 0;
@@ -1388,7 +1406,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                p->bdev = bdev;
        } else if (S_ISREG(inode->i_mode)) {
                p->bdev = inode->i_sb->s_bdev;
-               down(&inode->i_sem);
+               mutex_lock(&inode->i_mutex);
                did_down = 1;
                if (IS_SWAPFILE(inode)) {
                        error = -EBUSY;
@@ -1475,7 +1493,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
                        goto bad_swap;
                if (swap_header->info.nr_badpages > MAX_SWAP_BADPAGES)
                        goto bad_swap;
-               
+
                /* OK, set up the swap map and apply the bad block list */
                if (!(p->swap_map = vmalloc(maxpages * sizeof(short)))) {
                        error = -ENOMEM;
@@ -1484,17 +1502,17 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
 
                error = 0;
                memset(p->swap_map, 0, maxpages * sizeof(short));
-               for (i=0; i<swap_header->info.nr_badpages; i++) {
-                       int page = swap_header->info.badpages[i];
-                       if (page <= 0 || page >= swap_header->info.last_page)
+               for (i = 0; i < swap_header->info.nr_badpages; i++) {
+                       int page_nr = swap_header->info.badpages[i];
+                       if (page_nr <= 0 || page_nr >= swap_header->info.last_page)
                                error = -EINVAL;
                        else
-                               p->swap_map[page] = SWAP_MAP_BAD;
+                               p->swap_map[page_nr] = SWAP_MAP_BAD;
                }
                nr_good_pages = swap_header->info.last_page -
                                swap_header->info.nr_badpages -
                                1 /* header page */;
-               if (error) 
+               if (error)
                        goto bad_swap;
        }
 
@@ -1578,7 +1596,7 @@ out:
        if (did_down) {
                if (!error)
                        inode->i_flags |= S_SWAPFILE;
-               up(&inode->i_sem);
+               mutex_unlock(&inode->i_mutex);
        }
        return error;
 }