From: Andrew Morton <akpm@osdl.org>
To: linux-kernel@vger.kernel.org
Cc: timur.tabi@ammasso.com, roland@topspin.com
Subject: Re: Correct way to release get_user_pages()?
Date: Mon, 31 Jan 2005 13:01:04 -0800 [thread overview]
Message-ID: <20050131130104.4ac732e5.akpm@osdl.org> (raw)
In-Reply-To: <41FE53EA.4010101@ammasso.com>
Timur Tabi <timur.tabi@ammasso.com> wrote:
>
> Andrew Morton wrote:
>
> > no... You should only dirty the page if it was modified, and then use
> > set_page_dirty() or set_page_dirty_lock().
>
> If the page was modified, then shouldn't it already be marked dirty?
If the page is modified by a DMA transfer or by the CPU via the kernel's
page mappings then there is no record of its having been altered. Which is
why we must do it in software.
> Also, should I always use set_page_dirty_lock() if I haven't already
> locked the page?
If you don't have a reference on the page's inode, yes, you should use
set_page_dirty_lock(). If the page came from get_user_pages() then surely
you don't have a ref on the inode.
prev parent reply other threads:[~2005-01-31 21:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-28 3:02 Roland Dreier
2005-01-28 17:48 ` Timur Tabi
2005-01-30 10:10 ` Andrew Morton
2005-01-31 15:51 ` Timur Tabi
2005-01-31 21:01 ` Andrew Morton [this message]
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