From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: [PATCH RFC] rdma/ib: Add trace point macros to display human-readable values Date: Thu, 2 Nov 2017 08:06:01 +0200 Message-ID: <20171102060601.GW16127@mtr-leonro.local> References: <20171030215809.31286.46685.stgit@manet.1015granger.net> <20171101062743.GO16127@mtr-leonro.local> <20171101112932.4485ba6a@gandalf.local.home> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dZflLWwKqQHwno8z" Return-path: Content-Disposition: inline In-Reply-To: <20171101112932.4485ba6a-f9ZlEuEWxVcJvu8Pb33WZ0EMvNT87kid@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Steven Rostedt Cc: Bart Van Assche , Chuck Lever , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jonathan Corbet List-Id: linux-rdma@vger.kernel.org --dZflLWwKqQHwno8z Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Nov 01, 2017 at 11:29:32AM -0400, Steven Rostedt wrote: > On Wed, 1 Nov 2017 08:27:43 +0200 > Leon Romanovsky wrote: > > > On Mon, Oct 30, 2017 at 06:01:23PM -0400, Chuck Lever wrote: > > > These can be shared with all kernel ULPs, and more can easily be > > > added as needed. > > > > > > Signed-off-by: Chuck Lever > > > --- > > > include/trace/events/rdma.h | 128 +++++++++++++++++++++++++++++++++++++++++++ > > > 1 file changed, 128 insertions(+) > > > create mode 100644 include/trace/events/rdma.h > > > > > > Hi- > > > > > > I'm putting together a series of patches for v4.16 (or later) that > > > add static ftrace trace points to the RPC-over-RDMA client imple- > > > mentation. As part of that effort, I've constructed some trace point > > > helpers that might be useful for other kernel ULPs. > > > > > > So far this patch adds just helpers that xprtrdma needs. It is not > > > complete, but additional helpers can be introduced as they are > > > needed. > > > > > > I'd like to hear comments about these, or please let me know if > > > such helpers already exist and where xprtrdma can find them. > > > > Bart, Steve > > > > You attended the MS track, and for the rest of us, the quote below > > sounds a little bit cryptic. Does the quote below mean that Chuck's > > proposal is no-go? > > Actually, I wasn't invited to the Maintainer's Summit. Perhaps I should > have been. > > > > > From LWN.net "Another attempt to address the tracepoint ABI problem" [1] > > > > "The solution that was arrived at for now, as related by Torvalds, > > is to hold off on adding explicit tracepoints to the kernel. Instead, > > support will be added to make it easy for an application to attach a > > BPF script to any function in the kernel, with access to that function's > > arguments." > > > > [1] https://lwn.net/Articles/737530/ > > What I can tell you is what I talked to Linus about when I cornered him > in the hallway. ;-) > > Basically, nothing has changed. If a maintainer is fine with > trace events, then they can add new trace events. The issue is with the > maintainers that don't want the possibility of having to maintain stale > trace events because some tool depends on them and it becomes a burden > in the future. This is mostly an issues with the scheduler and VFS. > > What Linus asked me to do is to build an infrastructure on top of > ftrace, and make it easier to extract data from these "dynamic function > trace events". I need to add easier use cases for eBPF because the > usage of eBPF is still a large learning curve compared to the ease of > accessing the current trace event infrastructure. > > I'll be working on this in the very near future, but I don't expect > anything to be useful for within a year's time. Thus, continue doing > what you have been doing, and hopefully in a year we will be able to > extract more data from the kernel from anywhere a function is traced. Thanks > > -- Steve > --dZflLWwKqQHwno8z Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkhr/r4Op1/04yqaB5GN7iDZyWKcFAln6tckACgkQ5GN7iDZy WKfY7Q/+PEFquwKjO8QxxFJ/1v5OJ8efZIER/eHFEvSFkE1VOhp7ZLYyxpyDHNkS 8tAxmIuxjSJ5q0YsjIAawkpMl7z8+1lbXSl3ZZBrabWGxaUO5w+IsPHlVfF0ZagH UACeB1yw9C5U+jOgc4cl5Xfai7EUaoQ9hv0dV7iiUFKfziwaC6tagtpNQGKYGXm1 S8Gsn+5HkVXsI+e57zA/kqQ6F2EsFZRfvRhpzJE7yD4RaOzo2rgm3q8/xgc/g7dR Ws8/SizcOmC3viB5Xk0aA40d3kgfVtrK63vbNO5ort6iXkmknMlYFu74SVImuflD ako/9+zran0xqjPNgAtc+UY5feNueZi82f3wFct4qXAnJlFUK+hyUMJVhlgg/V/z Zpxr/5vku1tRBvFLqlSpGtfG9gLqiSJ9CzbwHCEXlwV0e+SsCzxrFSH0XfVpfW00 9rKE2eJkGCEZvY5BVxHqsTE1NjMqIz7+JansDdgPbIsblFJ0eoqh4drsO+vjcUX9 AQfuU0FAhuXHp5Y+YwsK+oWm6Ow8f1IvrH8NcfAn6nR/jOYiSQX1fnq3UPwxiXSC 9bP8mD7qY+hPXPTv28dqDPFyuAqVC5W0MxeqKJZbtPs1VH/bS1TrMFyd+AFog5F4 5wiRufitZF+3O9eoIyf+tjpWqQYrAPnec/ZLhlPS/L0EX7C9e6I= =9nIC -----END PGP SIGNATURE----- --dZflLWwKqQHwno8z-- -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html