diff options
| author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2014-06-04 16:07:48 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:54:02 -0700 |
| commit | dd6bd0d9c7dbb3951005db4e424abbd37c4ff801 (patch) | |
| tree | cddb3dcb163db01dd9af6e39ca4aee6f1a5470c5 /mm/page_io.c | |
| parent | 47a191fd38ebddb1bd1510ec2bc1085c578c8868 (diff) | |
swap: use bdev_read_page() / bdev_write_page()
By calling the device driver to write the page directly, we avoid
allocating a BIO, which allows us to free memory without allocating
memory.
[akpm@linux-foundation.org: fix used-uninitialized bug]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dheeraj Reddy <dheeraj.reddy@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_io.c')
| -rw-r--r-- | mm/page_io.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/mm/page_io.c b/mm/page_io.c index 7c59ef681381..58b50d2901fe 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -248,11 +248,16 @@ out: return ret; } +static sector_t swap_page_sector(struct page *page) +{ + return (sector_t)__page_file_index(page) << (PAGE_CACHE_SHIFT - 9); +} + int __swap_writepage(struct page *page, struct writeback_control *wbc, void (*end_write_func)(struct bio *, int)) { struct bio *bio; - int ret = 0, rw = WRITE; + int ret, rw = WRITE; struct swap_info_struct *sis = page_swap_info(page); if (sis->flags & SWP_FILE) { @@ -297,6 +302,13 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc, return ret; } + ret = bdev_write_page(sis->bdev, swap_page_sector(page), page, wbc); + if (!ret) { + count_vm_event(PSWPOUT); + return 0; + } + + ret = 0; bio = get_swap_bio(GFP_NOIO, page, end_write_func); if (bio == NULL) { set_page_dirty(page); @@ -338,6 +350,13 @@ int swap_readpage(struct page *page) return ret; } + ret = bdev_read_page(sis->bdev, swap_page_sector(page), page); + if (!ret) { + count_vm_event(PSWPIN); + return 0; + } + + ret = 0; bio = get_swap_bio(GFP_KERNEL, page, end_swap_bio_read); if (bio == NULL) { unlock_page(page); |