[PATCH] __block_write_full_page speedup
Remove all those get_bh()'s and put_bh()'s by extending lock_page() to cover
the troublesome regions.
(get_bh() and put_bh() happen every time whereas contention on a page's lock
in there happens basically never).
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/buffer.c b/fs/buffer.c
index bc75f2e..6f2c330 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1826,7 +1826,6 @@
}
if (test_clear_buffer_dirty(bh)) {
mark_buffer_async_write(bh);
- get_bh(bh);
last_bh = bh;
} else {
unlock_buffer(bh);
@@ -1839,20 +1838,19 @@
*/
BUG_ON(PageWriteback(page));
set_page_writeback(page);
- unlock_page(page);
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
submit_bh(WRITE, bh);
nr_underway++;
- put_bh(bh);
if (bh == last_bh)
break;
}
bh = next;
} while (bh != head);
bh = head;
+ unlock_page(page);
err = 0;
done:
@@ -1894,7 +1892,6 @@
if (buffer_mapped(bh) && buffer_dirty(bh)) {
lock_buffer(bh);
mark_buffer_async_write(bh);
- get_bh(bh);
last_bh = bh;
} else {
/*
@@ -1914,7 +1911,6 @@
clear_buffer_dirty(bh);
submit_bh(WRITE, bh);
nr_underway++;
- put_bh(bh);
if (bh == last_bh)
break;
}