From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Fri, 5 Feb 2010 04:48:42 -0500 Subject: [Cluster-devel] [PATCH 1/4] gfs2: add IO submission trace points In-Reply-To: <1265363394.2524.3.camel@localhost> References: <1265348727-19347-1-git-send-email-dchinner@redhat.com> <1265348727-19347-2-git-send-email-dchinner@redhat.com> <1265363394.2524.3.camel@localhost> Message-ID: <20100205094841.GA22192@infradead.org> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Fri, Feb 05, 2010 at 09:49:54AM +0000, Steven Whitehouse wrote: > 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 > > --- > > 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? Yes, we could. The tracing code normally uses the _RET_IP_ wrapper for __builtin_return_address(0) for some reason, though.