Message-ID: <3C34E169.FFE2DBED@vnet.ibm.com>
Date: Thu, 03 Jan 2002 16:55:37 -0600
From: Tom Gall <tom_gall@vnet.ibm.com>
MIME-Version: 1.0
To: Michael Zhu <mylinuxk@yahoo.ca>
CC: linux-kernel@vger.kernel.org
Subject: Re: The CURRENT macro
In-Reply-To: <20020103213455.34699.qmail@web14911.mail.yahoo.com>
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Sender: linux-kernel-owner@vger.kernel.org

Michael Zhu wrote:
> 
> In Alessandro Rubini's book Linux Device Driver(Second
> Edition), Chatper 12, he said that "By accessing the
> fields in the request structure, usually by way of
> CURRENT" and "CURRENT is just a pointer into
> blk_dev[MAJOR_NR].request_queue". I know CURRENT is
> just a macro. Where can I find the definition of this
> macro?
> I just don't know how to get the struct request from
> the request_queue(a request_queue_t struct). CURRENT
> points to which field in the
> blk_dev[MAJOR_NR].request_queue? Thank you very much.

Look in include/asm-[your-arch]/current.h

It's architecture dependant. For instance on PPC64 we keep current in a
register.

Regards,

Tom

-- 
Tom Gall - [embedded] [PPC64 | PPC32] Code Monkey
Peace, Love &                  "Where's the ka-boom? There was
Linux Technology Center         supposed to be an earth
http://www.ibm.com/linux/ltc/   shattering ka-boom!"
(w) tom_gall@vnet.ibm.com       -- Marvin Martian
(w) 507-253-4558
(h) tgall@rochcivictheatre.org
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