[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4713F5B8.9000206@goop.org>
Date: Mon, 15 Oct 2007 16:20:24 -0700
From: Jeremy Fitzhardinge <jeremy@...p.org>
To: Dave Hansen <haveblue@...ibm.com>
CC: Matt Mackall <mpm@...enic.com>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-kernel@...r.kernel.org,
Rusty Russell <rusty@...tcorp.com.au>,
David Rientjes <rientjes@...gle.com>,
Fengguang Wu <wfg@...l.ustc.edu.cn>,
"ADAM G. LITKE [imap]" <agl@...ibm.com>
Subject: Re: [PATCH 4/11] maps3: introduce a generic page walker
Dave Hansen wrote:
> For now, we should probably document that these functions assume that
> the appropriate locks are held, and that there are no changes being made
> to the pagetables as we walk.
>
> However, I can see that people might want to use these in the future for
> establishing ptes. Perhaps a special code coming back from the
> ->pte_hole() function could indicate changes were made to the
> pagetables. I guess we could at least retry part of the loop where the
> hole call was made, like:
>
Yes. We already have apply_to_page_range(), which has the side effect
of creating the page range in order to apply a function to it. It would
be nice to be able to replicate its functionality with this page waker
so we can have just one.
> +int walk_page_range(struct mm_struct *mm,...
> +{
> ...
> + pgd = pgd_offset(mm, addr);
> + do {
> + next = pgd_addr_end(addr, end);
> + if (pgd_none_or_clear_bad(pgd)) {
> + if (walk->pte_hole)
> + err = walk->pte_hole(addr, next, private);
> if (err == -EAGAIN) { // or whatever we want
> pgd--;
> err = 0;
> }
> + if (err)
> + break;
> + continue;
> + }
>
> That wouldn't allow changes behind the walker, but it should allow them
> in the range that was walked by the ->pte_hole() function.
>
Yep.
J
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists