Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751035AbbGKOop (ORCPT ); Sat, 11 Jul 2015 10:44:45 -0400 Received: from mail-wg0-f53.google.com ([74.125.82.53]:36797 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbbGKOoo (ORCPT ); Sat, 11 Jul 2015 10:44:44 -0400 Date: Sat, 11 Jul 2015 16:44:38 +0200 From: Frederic Weisbecker To: Chris Metcalf Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] nohz: prevent tilegx network driver interrupts Message-ID: <20150711144436.GF10257@lerouge> References: <55A0175E.2010200@ezchip.com> <1436557045-5392-1-git-send-email-cmetcalf@ezchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436557045-5392-1-git-send-email-cmetcalf@ezchip.com> 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 Content-Length: 2551 Lines: 75 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. > > 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. > > 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. > > Signed-off-by: Chris Metcalf Looks good. Since it modifies nohz core stuff, do you mind if I take it? Thanks. > --- > drivers/net/ethernet/tile/tilegx.c | 4 +++- > include/linux/tick.h | 9 +++++++++ > 2 files changed, 12 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c > index a3f7610002aa..0a15acc075b3 100644 > --- a/drivers/net/ethernet/tile/tilegx.c > +++ b/drivers/net/ethernet/tile/tilegx.c > @@ -40,6 +40,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -2273,7 +2274,8 @@ static int __init tile_net_init_module(void) > tile_net_dev_init(name, mac); > > if (!network_cpus_init()) > - network_cpus_map = *cpu_online_mask; > + cpumask_and(&network_cpus_map, housekeeping_cpumask(), > + cpu_online_mask); > > return 0; > } > diff --git a/include/linux/tick.h b/include/linux/tick.h > index 3741ba1a652c..d3b00f0b2221 100644 > --- a/include/linux/tick.h > +++ b/include/linux/tick.h > @@ -160,6 +160,15 @@ static inline void tick_nohz_full_kick_all(void) { } > static inline void __tick_nohz_task_switch(struct task_struct *tsk) { } > #endif > > +static inline const struct cpumask *housekeeping_cpumask(void) > +{ > +#ifdef CONFIG_NO_HZ_FULL > + if (tick_nohz_full_enabled()) > + return housekeeping_mask; > +#endif > + return cpu_possible_mask; > +} > + > static inline bool is_housekeeping_cpu(int cpu) > { > #ifdef CONFIG_NO_HZ_FULL > -- > 2.1.2 > -- 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/