From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: [RFC][PATCH RT] rwsem_rt: Another (more sane) approach to mulit reader rt locks Date: Thu, 17 May 2012 08:47:55 -0700 Message-ID: <20120517154755.GG2567@linux.vnet.ibm.com> References: <1337090625.14207.304.camel@gandalf.stny.rr.com> <20120517151838.GA8692@linux.vnet.ibm.com> <1337268779.4281.38.camel@twins> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Steven Rostedt , LKML , RT , Thomas Gleixner , Clark Williams To: Peter Zijlstra Return-path: Content-Disposition: inline In-Reply-To: <1337268779.4281.38.camel@twins> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On Thu, May 17, 2012 at 05:32:59PM +0200, Peter Zijlstra wrote: > On Thu, 2012-05-17 at 08:18 -0700, Paul E. McKenney wrote: > > Some researchers at MIT RCU-ified this lock: > > > > http://people.csail.mit.edu/nickolai/papers/clements-bonsai.pdf > > Ah, as have I [1].. and they seem to have gotten about as far as I have, > which means almost there but not quite [2] :-) I had forgotten about that -- that was the first call for call_srcu(), if I remember correctly. > The most interesting case is file maps and they simply ignored those. > While I appreciate that from an academic pov, -- they can still write a > paper on the other interesting bits -- I don't really like it from a > practical point. > > [1] https://lkml.org/lkml/2010/1/4/257 > [2] https://lkml.org/lkml/2010/1/4/532 Hmmm... Do the recent dcache changes cover some of the things that Linus called out? Probably not, but some at least. Thanx, Paul