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authorDarrick J. Wong <darrick.wong@oracle.com>2016-06-21 11:53:28 +1000
committerDave Chinner <david@fromorbit.com>2016-06-21 11:53:28 +1000
commit479c641273df632478cda7fe76b833df64e319bc (patch)
treefcfade01ced0f2aab76e3366aaba93ad3d574acc /fs/xfs
parent3f94c441e2c3dea029a46a2326b2170acf2c7713 (diff)
downloadlinux-479c641273df632478cda7fe76b833df64e319bc.tar.bz2
xfs: enable buffer deadlock postmortem diagnosis via ftrace
Create a second buf_trylock tracepoint so that we can distinguish between a successful and a failed trylock. With this piece, we can use a script to look at the ftrace output to detect buffer deadlocks. [dchinner: update to if/else as per hch's suggestion] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/xfs_buf.c8
-rw-r--r--fs/xfs/xfs_trace.h1
2 files changed, 6 insertions, 3 deletions
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index e71cfbd5acb3..f14daebbc531 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -944,10 +944,12 @@ xfs_buf_trylock(
int locked;
locked = down_trylock(&bp->b_sema) == 0;
- if (locked)
+ if (locked) {
XB_SET_OWNER(bp);
-
- trace_xfs_buf_trylock(bp, _RET_IP_);
+ trace_xfs_buf_trylock(bp, _RET_IP_);
+ } else {
+ trace_xfs_buf_trylock_fail(bp, _RET_IP_);
+ }
return locked;
}
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index ea94ee0fe5ea..68f27f70e1ed 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -354,6 +354,7 @@ DEFINE_BUF_EVENT(xfs_buf_submit_wait);
DEFINE_BUF_EVENT(xfs_buf_bawrite);
DEFINE_BUF_EVENT(xfs_buf_lock);
DEFINE_BUF_EVENT(xfs_buf_lock_done);
+DEFINE_BUF_EVENT(xfs_buf_trylock_fail);
DEFINE_BUF_EVENT(xfs_buf_trylock);
DEFINE_BUF_EVENT(xfs_buf_unlock);
DEFINE_BUF_EVENT(xfs_buf_iowait);