From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrea Arcangeli <aarcange@redhat.com>
Subject: Re: mmu_notifiers: turn off lockdep around mm_take_all_locks
Date: Wed, 8 Jul 2009 01:30:14 +0200
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Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	Avi Kivity <avi@redhat.com>, kvm <kvm@vger.kernel.org>,
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To: Peter Zijlstra <peterz@infradead.org>
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On Tue, Jul 07, 2009 at 10:00:25PM +0200, Peter Zijlstra wrote:
> It does feel slightly weird to explicitly overflow that preempt count
> though.

That is actually fixable there without adding more bits to preempt
count, just call a global preempt_disable after lockdep_off and call a
spinlock version that doesn't preempt_disable (or preempt_enable after
every spin_lock..).

> But sure, something like the below would disable lockdep for the
> critical bits.. really don't like it though, but the alternative is
> modifying the rmap locking and I don't like that either :/

Once we add that, I guess we can also remove the spin_lock_nest_lock.