Re: [patch] 'virtual => physical page mapping cache',

Arjan van de Ven (arjanv@redhat.com)
28 Sep 2002 12:22:09 +0200


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On Fri, 2002-09-27 at 18:26, Linus Torvalds wrote:
>=20
> On Fri, 27 Sep 2002, Ingo Molnar wrote:
> >=20
> > the attached patch implements the virtual =3D> physical cache. Right no=
w
> > only the COW code calls the invalidation function, because futexes do n=
ot
> > need notification on unmap.
>=20
> Ok, looks good. Except you make get_user_page() do a write fault on the=20
> page, and one of the points of this approach was that that shouldn't even=
=20
> be needed. Or did I miss some case that does need it?

get_user_page() cannot/should not ever do a pagefault via the pagefault
code otherwise the coredump code will take the mmap semaphore
recursively and deadlock.

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