From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: Re: [PATCH v8 0/7] netdev: intel: Eliminate duplicate barriers on weakly-ordered archs Date: Tue, 03 Apr 2018 11:26:07 -0700 Message-ID: <1522779967.4236.22.camel@intel.com> References: <1522695990-31082-1-git-send-email-okaya@codeaurora.org> <92f46034-f041-05e4-56b7-01ae4cb04efc@codeaurora.org> Reply-To: jeffrey.t.kirsher@intel.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-sDGlL3n2opI4dFCtsSti" Cc: Netdev , Timur Tabi , sulrich@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org To: Sinan Kaya , Alexander Duyck , intel-wired-lan Return-path: Received: from mga02.intel.com ([134.134.136.20]:46533 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753045AbeDCSZU (ORCPT ); Tue, 3 Apr 2018 14:25:20 -0400 In-Reply-To: <92f46034-f041-05e4-56b7-01ae4cb04efc@codeaurora.org> Sender: netdev-owner@vger.kernel.org List-ID: --=-sDGlL3n2opI4dFCtsSti Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2018-04-03 at 13:50 -0400, Sinan Kaya wrote: > > > What do you think about this version? Did I miss any SMP > > > barriers? > >=20 > > I would say we should probably just drop the whole set and start > > over. > > If we don't need the wmb() we are going to need to go through and > > clean up all of these paths and consider the barriers when updating > > the layout of the code. > >=20 > > For example I have been thinking about it and in the case of x86 we > > are probably better off not bothering with the wmb() and > > writel_relaxed() and instead switch over to the smp_wmb() and > > writel() > > since in the case of a strongly ordered system like x86 or sparc > > this > > ends up translating out to a couple of compile barriers. > >=20 > > I will also need time to reevaluate the Rx paths since dropping the > > wmb() may have other effects which I need to verify. >=20 > Sounds good, I'll let you work on it. >=20 > @Jeff Kirsher: can you drop this version from your development branch > until > Alex posts the next version? Already on it, I will work with Alex on any possible future versions of these patches. --=-sDGlL3n2opI4dFCtsSti Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEiTyZWz+nnTrOJ1LZ5W/vlVpL7c4FAlrDxz8ACgkQ5W/vlVpL 7c7xOw//b3ZzVyN0EW0kQqpiEIcbNUkj/dOEYj4KBpGwHyG3DIHhF2W7/MRcw2eI dOh2TRymlFzqQVfQqXhRULvl9OaxgKv/vqBRCvZIvu/yVi7VV7enlElQMfJtIsev 5RnF+IqcGjVQrLqxzJe6dUKpHTuqSO0WGuGcda/uG/iFpqZSu554Ro+46nN/eh+U q2VbyAF3Y0/uuk2yi2ZRN7YPGmB/mZJI6kLXzxnsNSVIBJsRa+2PW7547UQttdyP hV7P8RqB1TKtyUrK7kIC3cGYS20hh6Nd48Nz5PkGy6KhhbcFp9ncMT3s+SgEAFvy RMbqI//rNFEoS/vUFk8gEU9NTkgGmas4/vMExhA/rfhMLOjjpb9UQ8HKVxmbg0Vg kHaDf/GL9uEa38zzQlJ28vh+46ast/TGVHvdBNuHwpfWO1xYeb61dNc5kxad/KIK pSwAE6FP/5JX14ShZ4yuvJpEcvkewE7apEYH3FhiCz7TXKBIuUlpAibQTVEkcvn+ 2CsH6qLNJGt6PtAyBAa8qg70R3rrK8oyNZumpNXbr3+j9NAa0tUFGRpxBvJZ//Zt Vn2gJJqNY9ABry29FOKPxe6pNHECRKx5k3sDGjVx/JLkFqd4ASVAtOtJzbP0B+TC PT3qiUpm65HOzG+RjurpEyA7+6IVy4TmnipR6IRk6cJYZ4TaQBc= =iKtG -----END PGP SIGNATURE----- --=-sDGlL3n2opI4dFCtsSti--