Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965215AbcJXQ4k (ORCPT ); Mon, 24 Oct 2016 12:56:40 -0400 Received: from anholt.net ([50.246.234.109]:52467 "EHLO anholt.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757556AbcJXQ4h (ORCPT ); Mon, 24 Oct 2016 12:56:37 -0400 From: Eric Anholt To: Greg KH , mzoran@crowfest.net Cc: daniels@collabora.com, noralf@tronnes.org, popcornmix@gmail.com, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] staging: vc04_services: Replace dmac_map_area with dmac_map_sg In-Reply-To: <20161024132421.GB20116@kroah.com> References: <20161024052932.28259-1-mzoran@crowfest.net> <20161024132421.GB20116@kroah.com> User-Agent: Notmuch/0.22.2+1~gb0bcfaa (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Mon, 24 Oct 2016 09:56:35 -0700 Message-ID: <87bmy9sn24.fsf@eliezer.anholt.net> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2422 Lines: 57 --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Greg KH writes: > On Sun, Oct 23, 2016 at 10:29:32PM -0700, mzoran@crowfest.net wrote: >> From: Michael Zoran >>=20 >> The original arm implementation uses dmac_map_area which is not >> portable. Replace it with an architecture neutral version >> which uses dma_map_sg. >>=20 >> As you can see that for larger page sizes, the dma_map_sg >> implementation is faster then the original unportable dma_map_area >> implementation.=20=20 >>=20 >> Test dmac_map_area dma_map_page dma_map_sg >> vchiq_test -b 4 10000 51us/iter 76us/iter 76us >> vchiq_test -b 8 10000 70us/iter 82us/iter 91us >> vchiq_test -b 16 10000 94us/iter 118us/iter 121us >> vchiq_test -b 32 10000 146us/iter 173us/iter 187us >> vchiq_test -b 64 10000 263us/iter 328us/iter 299us >> vchiq_test -b 128 10000 529us/iter 631us/iter 595us >> vchiq_test -b 256 10000 2285us/iter 2275us/iter 2001us >> vchiq_test -b 512 10000 4372us/iter 4616us/iter 4123us >>=20 >> For message sizes >=3D 64KB, dma_map_sg is faster then dma_map_page. >>=20 >> For message size >=3D 256KB, the dma_map_sg is the fastest >> implementation. > > What is the "normal" message size value when using this driver? For the contents of a bulk transfer, the performance case you care about is moving an image (video decode, camera, etc.), so on the order of 1MB. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJYDj1DAAoJELXWKTbR/J7oW/cP/AlBaFoYA21yPjKdlIvcfFT3 UmRjwguCw7qwU7UjZ7WuailjvINKxnSW/L2spvxHHnn1OtLPYiudBVY3tpfhRYzC c8cLo15nIWcJKDbLDubV66sOCmI+zs1hz7fChC6oSLcSH5ycHDUy6S+0YGmAC5JO pfghlLXyvafdYJQPbd2Jk5H8YNMlJOIUnOvemFSWTLCl/ChJNKFuA7r83IpTiwcZ 0ZH3kd+R8jYn8a4hP/m3q6KP5gNQeCCtGHVkW7TJ+AkPuCOAODi6pdGaEKw5yaCF 7LocmPgnrqHvTOnsmMDtj83lMfRsyE84qWbGSomp2mvsrqD1onj+1toAZPwTggbs 9cSTzcH836K4xtzEdTB3aOdq3eQU6AxkbmJEGXJN7LODginwBeHEHd8PJNPovcTG hYcznxuCzsZ2wuQIFYO4Aj9EQyoWXHe3ComqMvMLJAjT3WjyDn8OZe8T6MK7a0cD 0+jqCYfpxV118JfMpAKd6jmCD5meIlkcyuA2mCK8AKEoSQFp9U1LhuBJ4Vy8pUYB BuRzH7xDSODvtB2xWkkbpAqV7j6tGHDfUTy+hYMjtzB0hKVwfGuTlciX5unpcdAK N6Z486jS/y/cWOmpHhrAofQn79nC05ISrP2uQPMM4pgxcStRBFkea829nBejt7sV knR+F4xammfwXTD23Qce =OYIs -----END PGP SIGNATURE----- --=-=-=--