From: Eric Sandeen <sandeen@redhat.com>
Date: Thu, 28 Oct 2010 01:30:03 +0000 (-0400)
Subject: ext4: stop looping in ext4_num_dirty_pages when max_pages reached
X-Git-Tag: v2.6.37-rc1~76^2^2~45
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=659c6009ca2e3a01acc9881bafe5f55ef09c965b;p=~shefty%2Frdma-dev.git

ext4: stop looping in ext4_num_dirty_pages when max_pages reached

Today we simply break out of the inner loop when we have accumulated
max_pages; this keeps scanning forwad and doing pagevec_lookup_tag()
in the while (!done) loop, this does potentially a lot of work
with no net effect.

When we have accumulated max_pages, just clean up and return.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 4b8debeb396..d88ba4a9eff 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1207,8 +1207,10 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
 				break;
 			idx++;
 			num++;
-			if (num >= max_pages)
+			if (num >= max_pages) {
+				done = 1;
 				break;
+			}
 		}
 		pagevec_release(&pvec);
 	}