From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f65.google.com (mail-wm1-f65.google.com [209.85.128.65]) by dpdk.org (Postfix) with ESMTP id 2AE231B47B for ; Wed, 9 Jan 2019 14:14:32 +0100 (CET) Received: by mail-wm1-f65.google.com with SMTP id p6so8159976wmc.1 for ; Wed, 09 Jan 2019 05:14:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:content-transfer-encoding:mime-version; bh=3DauCjXCBR8jJBq6lMVG7ZJyO0pG3GmqhzIoo6ORsZw=; b=kZgRJ0vZ8ewlbICngK5k5wuWwPRBhH6sJ3DVGFyYm+FMav0gzQlRmnaTPEeD2iN0rn gU0O/ZN/BOuOsntDMPhEh26dheMHIlsqhMVeHHggxmROalgFLAX7B1tD6bWT7sfr6c1e o6Ss4vr+AE2cidOT5UFDQxfAEbV2jRAXgybiWHe7KDO1LAdVRY9FeYb5op5XdQgahw3v l53ycvzfVy7Aw4fg/L966AgKuCYyZgG6fNl82k58aNFPxkOYuK1pf2mrju13TLzbo/v5 TcH/wIZxjJRMO0Ye7q274tU6TkosQunO3Jq25OIjzSzvBLkaZGQBFhy1UgTfCLrt2xEV hA8g== X-Gm-Message-State: AJcUukc0hRDTyLIXkjz1FgTByaE+2MQ2v56Kd/p7GlwokYnakmt/Os3+ fQj/rldDuCtoUGIJczQmjC8= X-Google-Smtp-Source: ALg8bN5OA/EMwbEv0N9dJVDxBb6c1L2He7m7hzDQuSub76Em7o2RtxOGcaFL/8Uw/4NQ7HmaEQpsFw== X-Received: by 2002:a1c:f916:: with SMTP id x22mr5901837wmh.87.1547039671537; Wed, 09 Jan 2019 05:14:31 -0800 (PST) Received: from localhost ([2001:1be0:110d:fcfe:132c:a71a:1896:1395]) by smtp.gmail.com with ESMTPSA id v1sm75840534wrw.90.2019.01.09.05.14.30 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 09 Jan 2019 05:14:30 -0800 (PST) Message-ID: <1547039669.6022.57.camel@debian.org> From: Luca Boccassi To: Jerin Jacob Kollanukkaran , "thomas@monjalon.net" , "yskoh@mellanox.com" Cc: "shahafs@mellanox.com" , "Gavin.Hu@arm.com" , "dev@dpdk.org" Date: Wed, 09 Jan 2019 13:14:29 +0000 In-Reply-To: <9c0a7ac4623c45d19e216f670ea7cd064f12b1ae.camel@marvell.com> References: <20190109093915.40882-1-yskoh@mellanox.com> <68eb1e77e09e396a229920f10487b6e95ddce5c8.camel@marvell.com> <1547029195.6022.54.camel@debian.org> <9c0a7ac4623c45d19e216f670ea7cd064f12b1ae.camel@marvell.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Subject: Re: [dpdk-dev] [EXT] [PATCH] config: change default cache line size for ARMv8 with meson X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Jan 2019 13:14:32 -0000 On Wed, 2019-01-09 at 10:52 +0000, Jerin Jacob Kollanukkaran wrote: > On Wed, 2019-01-09 at 10:19 +0000, Luca Boccassi wrote: > > On Wed, 2019-01-09 at 10:09 +0000, Jerin Jacob Kollanukkaran wrote: > > > On Wed, 2019-01-09 at 01:39 -0800, Yongseok Koh wrote: > > > > --------------------------------------------------------------- > > > > ---- > > > > --- > > > > In config/arm64_armv8_linuxapp_gcc, maximum available cache > > > > line > > > > size > > > > (128B) in arm64 implementations is set by default for generic > > > > config. > > > > However, setting 64B is preferable for meson build in order to > > > > support > > > > majority of CPUs which don't have Implementor ID or Part Number > > > > programmed > > > > on chip. > > >=20 > > > Adding Luca to get input from distro build perspective. > > >=20 > > > If I understand it correctly, distro build will be using > > > the generic config/arm/arm64_armv8_linuxapp_gcc for generic > > > build. > > > If so, We can not change cache line size for generic config > > > as mentined the reason are > > > https://mails.dpdk.org/archives/dev/2019-January/122441.html > > >=20 > > >=20 > > > I think, I way forward is to add > > > config/arm/arm64_a72_linuxapp_gcc > > > for meson. This config can be used for all SoC with A72 armv8=C2=A0 > > > implementation and may have sym link to specfific SoC to avoid > > > confusion to end users. > >=20 > > For Meson, I recently sent a patch to use a common and stable > > baseline > > machine arg if the uses sets it to "default": > >=20 > > https://patches.dpdk.org/patch/49477/ > >=20 > > For distros, I think if, within that path, the cache size is set to > > the > > minimum common denominator like the -march is, it will be fine. > >=20 > > At that point, what happens for "native" or otherwise specified > > builds > > it will not affect distros (as long as they use "default" like > > Debian > > and Ubuntu do). > >=20 >=20 > Thanks for the input >=20 > > Does this answer your question? >=20 >=20 > Kind of.. Will you be building "the generic image" on ANY arm64 > machine > with following command? >=20 > meson configure -Dmachine=3Ddefault > meson build > cd build > ninja > ninja install >=20 > If so, This patch will change the cache line size of generic build. > Right? Yes, that's the command used everywhere on Debian/Ubuntu, regardless of the machine type, and this patch will change the value for those cases as far as I can see. Please bear in mind that I know really little about arm, so I am not sure which should be the default for maximum compatibility. --=20 Kind regards, Luca Boccassi