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Date: Mon, 30 Sep 2013 09:05:51 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Michel Lespinasse <walken@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
        Waiman Long <Waiman.Long@hp.com>, Ingo Molnar <mingo@elte.hu>,
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        "Chandramouleeswaran, Aswin" <aswin@hp.com>,
        "Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH] rwsem: reduce spinlock contention in wakeup code path
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* Michel Lespinasse <walken@google.com> wrote:

> That said, I am very scared of using rwlock_t here, and I would much 
> prefer we choose a fair lock (either spinlock or a new rwlock 
> implementation which guarantees not to starve any locker thread)

Given how few users rwlock_t has today we could attempt to make it 
reader-writer fair, as long as the usecase of a hardirq or softirq
context always getting nested read access on the same CPU is preserved. 

(but that can be done - if nothing else then with an explicit context 
check.)

Thanks,

	Ingo
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