From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner+w=401wt.eu-S1754498AbZKVTv1@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754498AbZKVTv1 (ORCPT <rfc822;w@1wt.eu>);
	Sun, 22 Nov 2009 14:51:27 -0500
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753332AbZKVTv0
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Sun, 22 Nov 2009 14:51:26 -0500
Received: from smtp1.linux-foundation.org ([140.211.169.13]:50390 "EHLO
	smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK)
	by vger.kernel.org with ESMTP id S1753968AbZKVTvZ (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Sun, 22 Nov 2009 14:51:25 -0500
Date: Sun, 22 Nov 2009 11:51:03 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Ilya Loginov <isloginov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>, David Woodhouse <dwmw2@infradead.org>,
       linux-kernel@vger.kernel.org, Peter Horton <phorton@bitbox.co.uk>,
       "Ed L. Cashin" <ecashin@coraid.com>, Jens Axboe <jens.axboe@oracle.com>
Subject: Re: [PATCH] mtd: fix mtd_blkdevs problem with caches on some
 architectures (2.6.31)
Message-Id: <20091122115103.f57f0d0c.akpm@linux-foundation.org>
In-Reply-To: <20091122221836.d2d7535d.isloginov@gmail.com>
References: <20091118170810.2bb9cd54.isloginov@gmail.com>
	<20091120163751.731781e8.akpm@linux-foundation.org>
	<20091121170437.0839daef.isloginov@gmail.com>
	<20091121095429.1378828c.akpm@linux-foundation.org>
	<20091122021128.db47e202.isloginov@gmail.com>
	<20091121152633.8c79e341.akpm@linux-foundation.org>
	<20091122124631.908a32c4.isloginov@gmail.com>
	<20091122132915.GA3046@elte.hu>
	<20091122165521.0b488e05.isloginov@gmail.com>
	<20091122104816.b6920ede.akpm@linux-foundation.org>
	<20091122221836.d2d7535d.isloginov@gmail.com>
X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sun, 22 Nov 2009 22:18:36 +0300 Ilya Loginov <isloginov@gmail.com> wrote:

> On Sun, 22 Nov 2009 10:48:16 -0800
> Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > I don't think the non-stub versions of these should be inlined.  They
> > will generate quite a lot of code and they're pretty heavyweight.
> > Better to implement them in block/ somewhere, and EXPORT_SYMBOL().
> 
> I tried this way from the beginning, and to avoid redefinitions I enclose
> everything in #if #endif in *.c files. I think it is not very good.
> So there are two possibilities.
> 
> 1. To keep it like it is now and in this way there will be quite a lot of code.
> But in previous letters I gave statistics on the flush_dcache_page call in a
> kernel. And our case is particular. There will not be generated a lot of code.
> Or just take away inline.
> 
> 2. Or it is better to carry over normal realization to *.c file and enclose
> everything by one more #if #endif.
> 
> What do you consier to be better?

3. :)

In .h:

#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
extern void rq_flush_dcache_pages(struct request *rq);
#else
static inline void bio_flush_dcache_pages(struct bio *bi)
{
}
#endif

In .c:
	
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
void rq_flush_dcache_pages(struct request *rq)
{
	struct req_iterator iter;
	struct bio_vec* bvec;

	rq_for_each_segment(bvec, rq, iter)
		flush_dcache_page(bvec->bv_page);
}
EXPORT_SYMBOL(rq_flush_dcache_pages);
#endif