From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from investici.nine.ch ([217.150.252.179]:28417 "EHLO confino.investici.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754591Ab2EAUzY (ORCPT ); Tue, 1 May 2012 16:55:24 -0400 Date: Tue, 1 May 2012 22:56:17 +0200 From: Antonio Quartulli To: Emmanuel Grumbach Cc: "Venkataraman, Meenakshi" , "John W. Linville" , "linux-wireless@vger.kernel.org" Subject: Re: iwlwifi warn_slowpath with 3.* Message-ID: <20120501205616.GA2563@ritirata.org> (sfid-20120501_225530_529748_8B8DB7CC) References: <20120422182928.GA2854@ritirata.org> <20120430145803.GE2630@ritirata.org> <20120430170337.GA2560@tuxdriver.com> <4595B4D22AB93C4FABBA84AAD5AA37FD143115@ORSMSX103.amr.corp.intel.com> <20120501183415.GG4316@ritirata.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="J/dobhs11T7y2rNN" In-Reply-To: <20120501183415.GG4316@ritirata.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: --J/dobhs11T7y2rNN Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, May 01, 2012 at 08:34:15PM +0200, Antonio Quartulli wrote: > On Tue, May 01, 2012 at 08:13:46PM +0300, Emmanuel Grumbach wrote: > > Hi, > >=20 > > I am not sure the patch will help because the race is _very_ unlikely. > > But I would be glad to know if you can reproduce on latest > > compat-wireless. > > How reproducible is that on 3.3.3 ? Is that 100% ? >=20 > it seems so. It happens at least once at boot time. > I will try wireless-testing and see what happens. Then I will apply your = patch. The problem is there either with wireless-testing and with wireless-testing+your_patch. If it can somehow help, I also got several stack trace regarding intel_iova functions. But then the I got kernel panic and I was not able to copy the messages. Thanks > >=20 > > I guess my machine doesn't have IOMMU, but honestly, I am not sure I > > know how to check. > >=20 > > On Tue, May 1, 2012 at 19:52, Venkataraman, Meenakshi > > wrote: > > > > > > Hi John, Antonio, > > > > > > Emmanuel found a race condition in rx buffer allocation/deallocation,= and > > > attached is a patch that fixes it. > > > > > > >> > since linux-3.0 (I don't remember if it was the case even before= ), > > > >> > I'm getting this output in dmesg: > > > >> > > > > >> > [ =C2=A0 53.662990] ------------[ cut here ]------------ > > > >> > [ =C2=A0 53.663016] WARNING: at drivers/iommu/intel-iommu.c:2911 > > > >> > intel_unmap_page+0x14b/0x180() > > > >> > [ =C2=A0 53.663047] Hardware name: Latitude E5420 > > > >> > [ =C2=A0 53.663066] Driver unmaps unmatched page at PFN ffd1a000 > > > >> > > > >> > > > >> I see that I always get the same addr passed to the unmap function: > > > >> > > > >> [ =C2=A0 23.950535] Driver unmaps unmatched page at PFN ffd1a000 > > > >> > > > >> is it a coincidence? > > > >> I'm running linux-3.3.3 right now. I can try wireless-testing if it > > > >> would help. > > > > > > [MV] Antonio -- can you try out the patch attached and let us know if= you > > > continue to see the problem? > > > > > > >Just for the record, we are seeing a similar problem on RHEL 6.3 (wh= ich > > > > has an > > > >iwlwifi driver derived from linux-3.2). > > > > > > > > =C2=A0 =C2=A0 =C2=A0 https://bugzilla.redhat.com/show_bug.cgi?id=3D= 815998 > > > > > > [MV] John -- I'll update the redhat bugzilla as well. > > > > > > Thanks > > > Meenakshi >=20 > --=20 > Antonio Quartulli >=20 > ..each of us alone is worth nothing.. > Ernesto "Che" Guevara --=20 Antonio Quartulli =2E.each of us alone is worth nothing.. Ernesto "Che" Guevara --J/dobhs11T7y2rNN Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQEcBAEBAgAGBQJPoE3wAAoJEFMQTLzJFOZFR2MIAKoZn+oRnOhgm86zjtQnv+Hw Gcmp5ZoOHPKwghpTzripbhuTpQYjn1LSdIC0RZs48YxGU/ys4uiWZBUHiJiVg5de 15L1ayoiaDoJwrY5FmfUmR6VerZ8RYYCwc4BLW8dhGcZSLen0fYeM6loZ8Mhaa6P eOzt1gvFtS5pKXsNL+RENRG3YODDLMNsUoF6WAtS8/+aT7iGyxZEqzQvDxxxoDkr YY4yKb6Af65BIm4UtWMADyu3xcma/ufDGETukvWW1JRS/FbbKcBz6g/y1T22wKBv eV1a60xLhNQDH7cqwkEpl7pARGooQHBDnpRZnkE9POye9GcfxPDDr8RfW7+y6dU= =ALso -----END PGP SIGNATURE----- --J/dobhs11T7y2rNN--