Date: Tue, 14 Jul 2009 19:24:54 +0100 (BST)
From: Hugh Dickins <hugh.dickins@tiscali.co.uk>
To: Wu Fengguang <fengguang.wu@intel.com>
cc: Andrew Morton <akpm@linux-foundation.org>,
       LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH] shmem: call set_page_dirty() with locked page
In-Reply-To: <20090714092926.GA23969@localhost>
Message-ID: <Pine.LNX.4.64.0907141918380.10805@sister.anvils>
References: <20090714092926.GA23969@localhost>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1095
Lines: 34

On Tue, 14 Jul 2009, Wu Fengguang wrote:
> Here set_page_dirty() can be moved into the page lock.

Indeed it can, but you've forgotten to mention why you think
that would be a good thing?  All I can see is that it would
very very slightly increase the page's lock hold time, which
wouldn't be an improvement: what improvement are you making?

Hugh

> 
> CC: Hugh Dickins <hugh@veritas.com>
> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
> ---
>  mm/shmem.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- linux.orig/mm/shmem.c
> +++ linux/mm/shmem.c
> @@ -1630,8 +1630,8 @@ shmem_write_end(struct file *file, struc
>  	if (pos + copied > inode->i_size)
>  		i_size_write(inode, pos + copied);
>  
> -	unlock_page(page);
>  	set_page_dirty(page);
> +	unlock_page(page);
>  	page_cache_release(page);
>  
>  	return copied;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/