From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 10 Oct 2018 11:36:51 +1100 From: Dave Chinner To: "Darrick J. Wong" Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, ocfs2-devel@oss.oracle.com Subject: Re: [PATCH 01/25] xfs: add a per-xfs trace_printk macro Message-ID: <20181010003651.GH6311@dastard> References: <153913023835.32295.13962696655740190941.stgit@magnolia> <153913024554.32295.8692450593333636905.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153913024554.32295.8692450593333636905.stgit@magnolia> Sender: owner-linux-mm@kvack.org List-ID: On Tue, Oct 09, 2018 at 05:10:45PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > Add a "xfs_tprintk" macro so that developers can use trace_printk to > print out arbitrary debugging information with the XFS device name > attached to the trace output. > > Signed-off-by: Darrick J. Wong > --- > fs/xfs/xfs_error.h | 5 +++++ > 1 file changed, 5 insertions(+) > > > diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h > index 246d3e989c6c..c3d9546b138c 100644 > --- a/fs/xfs/xfs_error.h > +++ b/fs/xfs/xfs_error.h > @@ -99,4 +99,9 @@ extern int xfs_errortag_clearall(struct xfs_mount *mp); > #define XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040 > #define XFS_PTAG_FSBLOCK_ZERO 0x00000080 > > +/* trace printk version of xfs_err and friends */ > +#define xfs_tprintk(mp, fmt, args...) \ > + trace_printk("dev %d:%d " fmt, MAJOR((mp)->m_super->s_dev), \ > + MINOR((mp)->m_super->s_dev), ##args) > + > #endif /* __XFS_ERROR_H__ */ Not convinced this is a good idea. How are you going to ensure code calling this trace point is not committed? If we decide to add this, it needs to be a CONFIG_XFS_DEBUG=y only definition because trace_printk() is only for temporary debugging code and has substantial performance overheads even when these trace points are not being traced. Cheers, Dave. -- Dave Chinner david@fromorbit.com