From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Wed, 20 Jul 2016 11:56:12 +0200 Subject: [PATCH v2 1/5] ethernet: add sun8i-emac driver In-Reply-To: <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> References: <1469001800-11615-1-git-send-email-clabbe.montjoie@gmail.com> <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> Message-ID: <4697175.RMdFEWr9V5@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday, July 20, 2016 10:03:16 AM CEST LABBE Corentin wrote: > + > + /* Benched on OPIPC with 100M, setting more than 256 does not give any > + * perf boost > + */ > + priv->nbdesc_rx = 128; > + priv->nbdesc_tx = 256; > + > 256 tx descriptors can introduce a significant latency. Can you add support for BQL (netdev_sent_queue/netdev_completed_queue) to limit the queue size to the minimum? I also noticed that your tx_lock() prevents you from concurrently running sun8i_emac_complete_xmit() and sun8i_emac_xmit(). Is that necessary? I'd think that you can find a way to make them work concurrently. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver Date: Wed, 20 Jul 2016 11:56:12 +0200 Message-ID: <4697175.RMdFEWr9V5@wuerfel> References: <1469001800-11615-1-git-send-email-clabbe.montjoie@gmail.com> <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> Reply-To: arnd-r2nGTMty4D4@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Sender: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org In-Reply-To: <1469001800-11615-2-git-send-email-clabbe.montjoie-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: LABBE Corentin , robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, wens-jdAy2FN1RRM@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org List-Id: devicetree@vger.kernel.org On Wednesday, July 20, 2016 10:03:16 AM CEST LABBE Corentin wrote: > + > + /* Benched on OPIPC with 100M, setting more than 256 does not give any > + * perf boost > + */ > + priv->nbdesc_rx = 128; > + priv->nbdesc_tx = 256; > + > 256 tx descriptors can introduce a significant latency. Can you add support for BQL (netdev_sent_queue/netdev_completed_queue) to limit the queue size to the minimum? I also noticed that your tx_lock() prevents you from concurrently running sun8i_emac_complete_xmit() and sun8i_emac_xmit(). Is that necessary? I'd think that you can find a way to make them work concurrently. Arnd From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753900AbcGTJ5K (ORCPT ); Wed, 20 Jul 2016 05:57:10 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:57985 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753639AbcGTJ5I (ORCPT ); Wed, 20 Jul 2016 05:57:08 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: LABBE Corentin , robh+dt@kernel.org, mark.rutland@arm.com, maxime.ripard@free-electrons.com, wens@csie.org, linux@armlinux.org.uk, davem@davemloft.net, devicetree@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH v2 1/5] ethernet: add sun8i-emac driver Date: Wed, 20 Jul 2016 11:56:12 +0200 Message-ID: <4697175.RMdFEWr9V5@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-28-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> References: <1469001800-11615-1-git-send-email-clabbe.montjoie@gmail.com> <1469001800-11615-2-git-send-email-clabbe.montjoie@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:OVLguZnmFn/JdApArGGyAzOz8SWX4yD+/sfEafmEuOQZOyBUH4H FDhBoIMk8DTyTSFUSnIMblpeYQAVRtTJ9+eS5g1eoYsQhxjYPaWsR6QkBdE/0/dUBqP/7sd 8GSMOdWx8VK2ilT23+e8dBpP2Y4R5m5kN6+FtZ74aPS0K6Tac3FnnBBYByBEdxNZalLwqD4 8bhecGiVwCwy0ZK+/4WUQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:NVqp1r325dA=:j0eHKjlIJK4AIf2cigtcxD TOTCQ2ge2H5dzw5TrCjQBnjOpkKZQcWu4WK6TVcMzB5nSrImn9ndJaYMXgUrxP8sqMjbcbMGQ Oz/qCZwuvqydjeKwJ+wcA4dfX7xlkuqOSh3jMhC8Y+yS98GMD5gK3IENqWg3l8NvzUgloKPe0 CrwSUs2xCAeQCUQw2KbmSLVXMA7gCV0iOwhLjst5wIwmVB0Tqm5aR1XVtoMOKQdFRNJZch0ZP ECd5S0hNdhjIXgmypVmD8q6SBpLhPcormEIPlC9IlpOlzajs5WvthDwvDn3xlQdBHxXO2KrIW 1roi6m7BE1nuHBG+suW4l6rkyAc0ZKlM+DOrKnO2HGtCTMphNZHf9UQbTj32F0FxYR8+DMSyR S3J+leJ8J0x9yNeiSEHGqZfAJkg/FhTE+yY3ebkRnsBFgwavKrXq2JCJ0kulyKEl/lIb8lnqJ sWipOw4+GNhOI8mIhGoptRguRQAF8x9bNS6ForsLLQMmvBRO6bBXLkb6NLT/e5vY9ejZxaTi3 m1aXfhAA/drKJ9QVVZvzzKVZdz7SoO2hX3fC8ymSSK8CUqbEQsxfNcTiCN3WRCkansOqmIxWf vSb5D5azObUp3Sn3H9H1Hl++hZKQj4pF+rEjJMtx8/5Tg0NqlArOZY65wbFKB+01o3/t4Mm09 jJjxFu7rMcvYbGsbvk1Njn8MI5MaYxx0VFBeExDLxiPxspwawL+wFmruYTZ5dJPK7HcwjX7+l NI6Y/ULRZwe3eJTJ Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, July 20, 2016 10:03:16 AM CEST LABBE Corentin wrote: > + > + /* Benched on OPIPC with 100M, setting more than 256 does not give any > + * perf boost > + */ > + priv->nbdesc_rx = 128; > + priv->nbdesc_tx = 256; > + > 256 tx descriptors can introduce a significant latency. Can you add support for BQL (netdev_sent_queue/netdev_completed_queue) to limit the queue size to the minimum? I also noticed that your tx_lock() prevents you from concurrently running sun8i_emac_complete_xmit() and sun8i_emac_xmit(). Is that necessary? I'd think that you can find a way to make them work concurrently. Arnd