From 251d6a471c831e22880b3c146bb4556ddfb1dc82 Mon Sep 17 00:00:00 2001 From: Wu Fengguang Date: Wed, 1 Dec 2010 17:33:37 -0600 Subject: writeback: trace event writeback_single_inode It is valuable to know how the dirty inodes are iterated and their IO size. "writeback_single_inode: bdi 8:0: ino=134246746 state=I_DIRTY_SYNC|I_SYNC age=414 index=0 to_write=1024 wrote=0" - "state" reflects inode->i_state at the end of writeback_single_inode() - "index" reflects mapping->writeback_index after the ->writepages() call - "to_write" is the wbc->nr_to_write at entrance of writeback_single_inode() - "wrote" is the number of pages actually written v2: add trace event writeback_single_inode_requeue as proposed by Dave. CC: Dave Chinner Signed-off-by: Wu Fengguang --- fs/fs-writeback.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'fs/fs-writeback.c') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index f43c479feee..5185fad48b6 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -346,6 +346,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, struct writeback_control *wbc) { struct address_space *mapping = inode->i_mapping; + long nr_to_write = wbc->nr_to_write; unsigned dirty; int ret; @@ -368,6 +369,8 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, */ if (wbc->sync_mode != WB_SYNC_ALL) { requeue_io(inode, wb); + trace_writeback_single_inode_requeue(inode, wbc, + nr_to_write); return 0; } @@ -467,6 +470,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, } } inode_sync_complete(inode); + trace_writeback_single_inode(inode, wbc, nr_to_write); return ret; } -- cgit v1.2.3