Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752687AbbGJWpN (ORCPT ); Fri, 10 Jul 2015 18:45:13 -0400 Received: from skprod3.natinst.com ([130.164.80.24]:48011 "EHLO ni.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751918AbbGJWpG (ORCPT ); Fri, 10 Jul 2015 18:45:06 -0400 Date: Fri, 10 Jul 2015 17:45:00 -0500 From: Josh Cartwright To: Chris Metcalf Cc: Frederic Weisbecker , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] nohz: prevent tilegx network driver interrupts Message-ID: <20150710224500.GA25028@jcartwri.amer.corp.natinst.com> References: <55A0175E.2010200@ezchip.com> <1436557045-5392-1-git-send-email-cmetcalf@ezchip.com> MIME-Version: 1.0 In-Reply-To: <1436557045-5392-1-git-send-email-cmetcalf@ezchip.com> User-Agent: Mutt/1.5.23+89 (0255b37be491) (2014-03-12) X-MIMETrack: Itemize by SMTP Server on US-AUS-MGWOut2/AUS/H/NIC(Release 8.5.3FP6 HF1218|December 12, 2014) at 07/10/2015 05:45:00 PM, Serialize by Router on US-AUS-MGWOut2/AUS/H/NIC(Release 8.5.3FP6 HF1218|December 12, 2014) at 07/10/2015 05:45:00 PM, Serialize complete at 07/10/2015 05:45:00 PM Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SZSwH5G1FJ2Fz+jP" Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2015-07-11_01:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2029 Lines: 58 --SZSwH5G1FJ2Fz+jP Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jul 10, 2015 at 03:37:25PM -0400, Chris Metcalf wrote: > Normally the tilegx networking shim sends irqs to all the cores > to distribute the load of processing incoming-packet interrupts, > so that you can get to multiple Gb's of traffic inbound. >=20 > However, in nohz_full mode we don't want to interrupt the > nohz_full cores by default, so we limit the set of cores we use > to only the online housekeeping cores. >=20 > To make client code easier to read, we introduce a new nohz_full > accessor, housekeeping_cpumask(), which returns a pointer to the > housekeeping_mask if nohz_full is enabled, and otherwise returns > the cpu_possible_mask. >=20 > Signed-off-by: Chris Metcalf > --- [..] > +static inline const struct cpumask *housekeeping_cpumask(void) > +{ > +#ifdef CONFIG_NO_HZ_FULL > + if (tick_nohz_full_enabled()) > + return housekeeping_mask; > +#endif Just a small comment: We can take these checks out from under a #ifdef CONFIG_NO_HZ_FULL check, given that are stubbed tick_nohz_full_enabled() defined above. Josh --SZSwH5G1FJ2Fz+jP Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAABCAAGBQJVoErpAAoJEKp7ZBKwQFAr2J0IAKZ+LFQe7XEqsIl6SW0xeM2e QIIIexwOfTYQ7H+OrL7N2/RHvylPC0FuZAdq2+jMX0t5I5LAo2C7QN2h3ubF1fyb B9OyshJZrnQ+ssacx5z5HkbjOq3bCQvb+d/AIBiWg3ItuPlUBl7QeN3kXQ+/yWvn 4lXxicM2A+p3sf4tziGW+MBG9o2AkAp+ZsuX4/qhaFlqR/Ci7Fi8FpfzVj6PySic 2mVvbSCx3+esKATUbajdScnoTYjEaBPui8Bgd0gQednvkOyGrD9ZGtruyM8Phz2E fcx/QhaMnBHe/pUPpc24dLOoO6yqnFESUaeA5o/yVUzegAYNP1qymHtqi16572Y= =2Zbf -----END PGP SIGNATURE----- --SZSwH5G1FJ2Fz+jP-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/