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Date: Thu, 11 Aug 2005 14:06:02 +0800
From: David Teigland <teigland@redhat.com>
To: Arjan van de Ven <arjan@infradead.org>
Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, linux-cluster@redhat.com
Subject: Re: [PATCH 00/14] GFS
Message-ID: <20050811060602.GA12438@redhat.com>
References: <20050802071828.GA11217@redhat.com> <1122968724.3247.22.camel@laptopd505.fenrus.org>
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On Tue, Aug 02, 2005 at 09:45:24AM +0200, Arjan van de Ven wrote:

> * +	if (create)
> +		down_write(&ip->i_rw_mutex);
> +	else
> +		down_read(&ip->i_rw_mutex);
> 
> why do you use a rwsem and not a regular semaphore? You are aware that
> rwsems are far more expensive than regular ones right?  How skewed is
> the read/write ratio?

Rough tests show around 4/1, that high or low?