From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: Nick Piggin <npiggin@suse.de>
Cc: "Mika Penttilä" <mika.penttila@kolumbus.fi>,
"Tony Battersby" <tonyb@cybernetics.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
"Andrew Morton" <akpm@linux-foundation.org>
Subject: Re: [PATCH] more ZERO_PAGE handling ( was 2.6.24 regression: deadlock on coredump of big process)
Date: Wed, 7 May 2008 11:14:04 +0900 [thread overview]
Message-ID: <20080507111404.871b8990.kamezawa.hiroyu@jp.fujitsu.com> (raw)
In-Reply-To: <20080430061125.GF27652@wotan.suse.de>
On Wed, 30 Apr 2008 08:11:25 +0200
Nick Piggin <npiggin@suse.de> wrote:
> > pte = *ptep;
> > - if (!pte_present(pte))
> > + if (!pte_present(pte)) {
> > + if (!(flags & FOLL_WRITE) && pte_none(pte)) {
> > + pte_unmap_unlock(ptep, ptl);
> > + goto null_or_zeropage;
> > + }
> > goto unlock;
> > + }
>
> Just a small nitpick: I guess you don't need this FOLL_WRITE test because
> null_or_zeropage will test FOLL_ANON which implies !FOLL_WRITE. It should give
> slightly smaller code.
>
> Otherwise, looks good to me:
>
Hmm, but
do_execve()
-> copy_strings()
-> get_arg_page()
-> get_user_pages()
can do write-page-fault in ANON (and it's a valid ops.)
So, I think it's safe not to remove FOLL_WRITE check here.
Thanks,
-Kame
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next prev parent reply other threads:[~2008-05-07 2:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-28 15:11 2.6.24 regression: deadlock on coredump of big process Tony Battersby
2008-04-29 1:00 ` KAMEZAWA Hiroyuki
2008-04-29 14:10 ` Tony Battersby
2008-04-30 4:25 ` [PATCH] more ZERO_PAGE handling ( was 2.6.24 regression: deadlock on coredump of big process) KAMEZAWA Hiroyuki
2008-04-30 4:46 ` Nick Piggin
2008-04-30 5:03 ` Mika Penttilä
2008-04-30 5:09 ` Nick Piggin
2008-04-30 5:17 ` KAMEZAWA Hiroyuki
2008-04-30 5:19 ` Nick Piggin
2008-04-30 5:35 ` KAMEZAWA Hiroyuki
2008-04-30 6:11 ` Nick Piggin
2008-05-07 2:14 ` KAMEZAWA Hiroyuki [this message]
2008-05-07 2:27 ` KAMEZAWA Hiroyuki
2008-04-30 13:57 ` Tony Battersby
2008-05-01 8:39 ` kamezawa.hiroyu
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