From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753668AbcLHPxf (ORCPT ); Thu, 8 Dec 2016 10:53:35 -0500 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:49450 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751593AbcLHPxe (ORCPT ); Thu, 8 Dec 2016 10:53:34 -0500 Date: Thu, 8 Dec 2016 16:46:11 +0100 From: Pavel Machek To: David Miller Cc: LinoSanfilippo@gmx.de, bh74.an@samsung.com, ks.giri@samsung.com, vipul.pandya@samsung.com, peppe.cavallaro@st.com, alexandre.torgue@st.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH 2/2] net: ethernet: stmmac: remove private tx queue lock Message-ID: <20161208154611.GB24327@amd> References: <20161207213757.GC2250@amd> <20161207.184111.1365236213357532881.davem@davemloft.net> <20161208140846.GA24327@amd> <20161208.102641.2159772626439340664.davem@davemloft.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="IiVenqGWf+H9Y6IX" Content-Disposition: inline In-Reply-To: <20161208.102641.2159772626439340664.davem@davemloft.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --IiVenqGWf+H9Y6IX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu 2016-12-08 10:26:41, David Miller wrote: > From: Pavel Machek > Date: Thu, 8 Dec 2016 15:08:46 +0100 >=20 > > On Wed 2016-12-07 18:41:11, David Miller wrote: > >> From: Pavel Machek > >> Date: Wed, 7 Dec 2016 22:37:57 +0100 > >>=20 > >> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/dri= vers/net/ethernet/stmicro/stmmac/stmmac_main.c > >> > index 982c952..7415bc2 100644 > >> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > >> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c > >> > @@ -1308,7 +1308,7 @@ static void stmmac_tx_clean(struct stmmac_priv= *priv) > >> > unsigned int bytes_compl =3D 0, pkts_compl =3D 0; > >> > unsigned int entry =3D priv->dirty_tx; > >> > =20 > >> > - spin_lock(&priv->tx_lock); > >> > + netif_tx_lock_bh(priv->dev); > >> > =20 > >> > priv->xstats.tx_clean++; > >> > =20 > >>=20 > >> stmmac_tx_clean() runs from either the timer or the NAPI poll handler, > >> both execute from software interrupts, therefore _bh() should be > >> unnecessary. > >=20 > > I've tried the test again with netif_tx_lock() (not _bh()) and it > > survived for more then four hours. Strange... >=20 > It's not strange, it's completely expected. Well, I tried that exact test before, and it survived for something like 10 minutes. So yes... this surprised me. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --IiVenqGWf+H9Y6IX Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlhJgEIACgkQMOfwapXb+vJbIwCfX0EnABLxHqdo29/jDFMpccqY hH8AoJIhZwJs/2N1jlpqwv9rzgIC9Gjt =1gi6 -----END PGP SIGNATURE----- --IiVenqGWf+H9Y6IX--