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Date: Thu, 27 Jun 2013 03:37:14 +0200
From: Andi Kleen <andi@firstfloor.org>
To: Waiman Long <waiman.long@hp.com>
Cc: Andi Kleen <andi@firstfloor.org>, Alexander Viro <viro@zeniv.linux.org.uk>,
        Jeff Layton <jlayton@redhat.com>, Miklos Szeredi <mszeredi@suse.cz>,
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Subject: Re: [PATCH v2 1/2] spinlock: New spinlock_refcount.h for lockless
 update of refcount
Message-ID: <20130627013714.GM6123@two.firstfloor.org>
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> It will be hard to know what changes will be needed without knowing
> the exact semantics of the spinlock functions with lock elision. Can
> you explain a little more what bizarre semantics you are referring
> to?

Totally independent of elision.

For example, what semantics does spin_unlock_wait() have with a ticket
lock. Where in the queue does it wait?
It doesn't really make sense with a ticket lock.

What semantics would lockdep put on it?

-Andi