Date: Mon, 12 Dec 2005 11:59:10 +0200
From: "Michael S. Tsirkin" <mst@mellanox.co.il>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh@veritas.com>, Gleb Natapov <gleb@minantech.com>,
       Benjamin Herrenschmidt <benh@kernel.crashing.org>,
       Petr Vandrovec <vandrove@vc.cvut.cz>,
       Badari Pulavarty <pbadari@us.ibm.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: set_page_dirty vs set_page_dirty_lock
Message-ID: <20051212095910.GX14936@mellanox.co.il>
Reply-To: "Michael S. Tsirkin" <mst@mellanox.co.il>
References: <439D417E.903@yahoo.com.au>
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Quoting Nick Piggin <nickpiggin@yahoo.com.au>:
> >>or try to do something tricky with page_count to determine
> >>if we need to do a copy in fork() rather than a COW.
> > 
> > 
> > I'm actually reasonably happy with the trick that I'm using:
> > performing a second get_user_pages after DMA and comparing
> > the page lists.
> > However, doing this every time on the off chance that a
> > page was made COW forces me into task context, every time.
> > 
> 
> I think it might be possible to solve it with the early-copy in
> fork(). I'll tinker with it.

Thanks, that would help!

-- 
MST
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