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Date: Wed, 27 May 2015 08:53:49 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Oleg Nesterov <oleg@redhat.com>,
        Paul McKenney <paulmck@linux.vnet.ibm.com>, Tejun Heo <tj@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        der.herr@hofr.at
Subject: Re: [RFC][PATCH 0/5] Optimize percpu-rwsem
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On Tue, May 26, 2015 at 11:42:11AM -0700, Davidlohr Bueso wrote:

> Instead of dropping percpu-rwsem, I was thinking we could instead look
> for opportunities to convert new users, for instance shinkers, where the
> write lock is also taken just for register and unregister purposes,
> similar to uprobes.

Another 'obvious' one would be the cpu hotplug lock. That's basically
the same locking primitive with just a wee little difference.