ext4: Add debugging markers that can be used by systemtap
This debugging markers are designed to debug problems such as the
random filesystem latency problems reported by Arjan.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index c37d1e8..5afe437 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -28,6 +28,7 @@
#include <linux/writeback.h>
#include <linux/jbd2.h>
#include <linux/blkdev.h>
+#include <linux/marker.h>
#include "ext4.h"
#include "ext4_jbd2.h"
@@ -51,6 +52,10 @@
J_ASSERT(ext4_journal_current_handle() == NULL);
+ trace_mark(ext4_sync_file, "dev %s datasync %d ino %ld parent %ld",
+ inode->i_sb->s_id, datasync, inode->i_ino,
+ dentry->d_parent->d_inode->i_ino);
+
/*
* data=writeback:
* The caller's filemap_fdatawrite()/wait will sync the data.
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dfcd41f..9c02146 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -35,6 +35,7 @@
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
+#include <linux/marker.h>
#include <linux/log2.h>
#include <linux/crc16.h>
#include <asm/uaccess.h>
@@ -2951,6 +2952,7 @@
{
tid_t target;
+ trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
sb->s_dirt = 0;
if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
if (wait)
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index af4651b..42895d36 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -20,6 +20,7 @@
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/jbd2.h>
+#include <linux/marker.h>
#include <linux/errno.h>
#include <linux/slab.h>
@@ -328,6 +329,8 @@
* journal straight away.
*/
result = jbd2_cleanup_journal_tail(journal);
+ trace_mark(jbd2_checkpoint, "dev %s need_checkpoint %d",
+ journal->j_devname, result);
jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
if (result <= 0)
return result;
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index b091e53..e91f051 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -16,6 +16,7 @@
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/jbd2.h>
+#include <linux/marker.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/mm.h>
@@ -368,6 +369,8 @@
commit_transaction = journal->j_running_transaction;
J_ASSERT(commit_transaction->t_state == T_RUNNING);
+ trace_mark(jbd2_start_commit, "dev %s transaction %d",
+ journal->j_devname, commit_transaction->t_tid);
jbd_debug(1, "JBD: starting commit of transaction %d\n",
commit_transaction->t_tid);
@@ -985,6 +988,9 @@
}
spin_unlock(&journal->j_list_lock);
+ trace_mark(jbd2_end_commit, "dev %s transaction %d head %d",
+ journal->j_devname, commit_transaction->t_tid,
+ journal->j_tail_sequence);
jbd_debug(1, "JBD: commit %d complete, head %d\n",
journal->j_commit_sequence, journal->j_tail_sequence);