Re: [RFC v1 00/14] Implement call_rcu_lazy() and miscellaneous fixes

From: Joel Fernandes <joel@joelfernandes.org>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: rcu <rcu@vger.kernel.org>,
	Rushikesh S Kadam <rushikesh.s.kadam@intel.com>,
	"Uladzislau Rezki (Sony)" <urezki@gmail.com>,
	Neeraj upadhyay <neeraj.iitr10@gmail.com>,
	Frederic Weisbecker <frederic@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [RFC v1 00/14] Implement call_rcu_lazy() and miscellaneous fixes
Date: Thu, 16 Jun 2022 12:26:35 -0400	[thread overview]
Message-ID: <CAEXW_YQWeDLNSw9MhPum+ABB2tzDVoLvg1KSxhnaKdhS7EsZNA@mail.gmail.com> (raw)
In-Reply-To: <20220613224843.GJ1790663@paulmck-ThinkPad-P17-Gen-1>

On Mon, Jun 13, 2022 at 6:48 PM Paul E. McKenney <paulmck@kernel.org> wrote:
>
> On Mon, Jun 13, 2022 at 06:53:27PM +0000, Joel Fernandes wrote:
> > On Thu, May 12, 2022 at 03:04:28AM +0000, Joel Fernandes (Google) wrote:
> > > Hello!
> > > Please find the proof of concept version of call_rcu_lazy() attached. This
> > > gives a lot of savings when the CPUs are relatively idle. Huge thanks to
> > > Rushikesh Kadam from Intel for investigating it with me.
> >
> > Just a status update, we're reworking this code to use the bypass lists which
> > takes care of a lot of corner cases. I've had to make changes the the rcuog
> > thread code to handle wakes up a bit differently and such. Initial testing is
> > looking good. Currently working on the early-flushing of the lazy CBs based
> > on memory pressure.
> >
> > Should be hopefully sending v2 soon!
>
> Looking forward to seeing it!

Looks like rebasing on paul's dev is needed for me to even apply test
on our downstream kernels.  Why you ask? Because our downstream folks
are indeed using upstream 5.19-rc3. =) Finally rebase succeeded and
now I can test lazy bypass downstream before sending out the next
RFC...

 - Joel