Commit 05937baa authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
Browse files

[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: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ad576e63

fs/buffer.c

+1 −5
Original line number Diff line number Diff line
@@ -1826,7 +1826,6 @@ static int __block_write_full_page(struct inode *inode, struct page *page, 
		}

		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 @@ static int __block_write_full_page(struct inode *inode, struct page *page, 
	 */

	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 @@ recover: 
		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 @@ recover: 
			clear_buffer_dirty(bh);

			submit_bh(WRITE, bh);

			nr_underway++;

			put_bh(bh);

			if (bh == last_bh)

				break;

		}

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