lkml.org 
[lkml]   [2010]   [Nov]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/3] fs: pull inode->i_lock up out of writeback_single_inode
Date
From: Dave Chinner <dchinner@redhat.com>

First thing we do in writeback_single_inode() is take the i_lock and
the last thing we do is drop it. A caller already holds the i_lock,
so pull the i_lock out of writeback_single_inode() to reduce the
round trips on this lock during inode writeback.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/fs-writeback.c | 15 ++++++++-------
1 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index f53486f..bd199f4 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -318,9 +318,9 @@ static void inode_wait_for_writeback(struct inode *inode)
}

/*
- * Write out an inode's dirty pages. Called under inode_wb_list_lock. Either
- * the caller has an active reference on the inode or the inode has I_WILL_FREE
- * set.
+ * Write out an inode's dirty pages. Called under inode_wb_list_lock and
+ * inode->i_lock. Either the caller has an active reference on the inode or
+ * the inode has I_WILL_FREE set.
*
* If `wait' is set, wait on the writeout.
*
@@ -335,7 +335,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
unsigned dirty;
int ret;

- spin_lock(&inode->i_lock);
if (!atomic_read(&inode->i_count))
WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING)));
else
@@ -351,7 +350,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
* completed a full scan of b_io.
*/
if (wbc->sync_mode != WB_SYNC_ALL) {
- spin_unlock(&inode->i_lock);
requeue_io(inode);
return 0;
}
@@ -442,7 +440,6 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
}
}
inode_sync_complete(inode);
- spin_unlock(&inode->i_lock);
return ret;
}

@@ -530,7 +527,6 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
}

__iget(inode);
- spin_unlock(&inode->i_lock);

pages_skipped = wbc->pages_skipped;
writeback_single_inode(inode, wbc);
@@ -541,6 +537,7 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb,
*/
redirty_tail(inode);
}
+ spin_unlock(&inode->i_lock);
spin_unlock(&inode_wb_list_lock);
iput(inode);
cond_resched();
@@ -1208,7 +1205,9 @@ int write_inode_now(struct inode *inode, int sync)

might_sleep();
spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
ret = writeback_single_inode(inode, &wbc);
+ spin_unlock(&inode->i_lock);
spin_unlock(&inode_wb_list_lock);
if (sync)
inode_sync_wait(inode);
@@ -1232,7 +1231,9 @@ int sync_inode(struct inode *inode, struct writeback_control *wbc)
int ret;

spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
ret = writeback_single_inode(inode, wbc);
+ spin_unlock(&inode->i_lock);
spin_unlock(&inode_wb_list_lock);
return ret;
}
--
1.7.1


\
 
 \ /
  Last update: 2010-11-01 06:37    [W:0.058 / U:0.144 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site