Date: Fri, 21 Sep 2007 22:11:22 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: "Chris Friesen" <cfriesen@nortel.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: question on kernel rwsem behaviour
Message-ID: <20070921221122.7776e0ec@lappy>
In-Reply-To: <46F3E584.4020301@nortel.com>
References: <46F3E584.4020301@nortel.com>
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On Fri, 21 Sep 2007 09:38:44 -0600 "Chris Friesen"
<cfriesen@nortel.com> wrote:

> 
> Hi all,
> 
> I just had a quick question on read-write semaphore semantics.  Suppose 
> someone holds a sema for reading, then someone else tries to aquire it 
> for writing, and blocks.  Finally, a third code path tries to aquire it 
> for reading.
> 
> Does this third code path get the sema, or does it wait for the writer?
> 
> Based on looking at the implementation it seems like it waits, but I'd 
> like to confirm that.

Yes, its fair in that sense.
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