Date: Thu, 13 Apr 2017 09:37:10 -0700
From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com,
        dipankar@in.ibm.com, akpm@linux-foundation.org,
        mathieu.desnoyers@efficios.com, josh@joshtriplett.org,
        tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com,
        edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com,
        bobby.prani@gmail.com
Subject: Re: [PATCH tip/core/rcu 40/40] srcu: Parallelize callback handling
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On Thu, Apr 13, 2017 at 11:50:29AM +0200, Peter Zijlstra wrote:
> On Wed, Apr 12, 2017 at 10:40:25AM -0700, Paul E. McKenney wrote:
> > Peter Zijlstra proposed using SRCU to reduce mmap_sem contention [1],
> 
> Bugger, now you're making me feel bad for not having updated those
> patches in ages.. I'll try and bump it on the todo list.

Apologies, I wasn't trying to make you feel bad.  But I did get an old
version of the patch.  A much more recent one is here, which I have
added to the commit log:

	https://patchwork.kernel.org/patch/5108281/

For my part, I feel bad that I didn't realize much earlier that parallel
SRCU callbacks were needed.  As it was, someone had to tell me late
last year.

But yes, it would be really cool to have lockless VMA lookup!!!

							Thanx, Paul