[Cluster-devel] [PATCH 1/4] gfs2: add IO submission trace points

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

On Fri, 2010-02-05 at 16:45 +1100, Dave Chinner wrote:
> Useful for tracking down where specific IOs are being issued
> from.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---
>  fs/gfs2/log.c        |    6 ++++++
>  fs/gfs2/lops.c       |    6 ++++++
>  fs/gfs2/trace_gfs2.h |   41 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 53 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
> index 4511b08..bd26dff 100644
> --- a/fs/gfs2/log.c
> +++ b/fs/gfs2/log.c
> @@ -121,6 +121,7 @@ __acquires(&sdp->sd_log_lock)
>  			lock_buffer(bh);
>  			if (test_clear_buffer_dirty(bh)) {
>  				bh->b_end_io = end_buffer_write_sync;
> +				trace_gfs2_submit_bh(bh, WRITE_SYNC_PLUG, __func__);
>  				submit_bh(WRITE_SYNC_PLUG, bh);
This looks like it could be a generically useful function, I wonder if
it would be possible to do this directly in submit_bh, since we should
be able to use __builtin_return_address(0) to find out the origin of the
call?

Steve.