Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 7 Aug 2004 21:27:03 -0700
From:      Kris Kennaway <kris@obsecurity.org>
To:        John Baldwin <jhb@FreeBSD.org>
Cc:        cvs-all@FreeBSD.org
Subject:    Re: cvs commit: src/sys/i386/i386 pmap.c src/sys/kern subr_witness.c
Message-ID:  <20040808042703.GA64746@xor.obsecurity.org>
In-Reply-To: <200408041634.03998.jhb@FreeBSD.org>
References:  <200408042031.i74KVKUf039025@repoman.freebsd.org> <200408041634.03998.jhb@FreeBSD.org>

next in thread | previous in thread | raw e-mail | index | archive | help

--J/dobhs11T7y2rNN
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Aug 04, 2004 at 04:34:03PM -0400, John Baldwin wrote:
> On Wednesday 04 August 2004 04:31 pm, John Baldwin wrote:
> > jhb         2004-08-04 20:31:19 UTC
> >
> >   FreeBSD src repository
> >
> >   Modified files:
> >     sys/i386/i386        pmap.c
> >     sys/kern             subr_witness.c
> >   Log:
> >   Remove a potential deadlock on i386 SMP by changing the lazypmap ipi =
and
> >   spin-wait code to use the same spin mutex (smp_tlb_mtx) as the TLB ipi
> >   and spin-wait code snippets so that you can't get into the situation =
of
> >   one CPU doing a TLB shootdown to another CPU that is doing a lazy pmap
> >   shootdown each of which are waiting on each other.  With this change,
> > only one of the CPUs would do an IPI and spin-wait at a time.
>=20
> Both this patch and the previous I have tested locally and also sent out =
to=20
> current@ for testing.  However, I received zero feedback (not even useles=
s=20
> feedback), so they may theoretically be risky.

Isn't this the patch I tested for you and reported that it did not fix
the problem?

Kris

--J/dobhs11T7y2rNN
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (FreeBSD)

iD8DBQFBFauXWry0BWjoQKURAtsSAJwLfr/lnd0zZHfqElt5mrLNikajYQCg7Al9
IKfOqloZUDxUB7G9tvBbSnw=
=g0s5
-----END PGP SIGNATURE-----

--J/dobhs11T7y2rNN--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040808042703.GA64746>