From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 65538A0C41; Thu, 16 Sep 2021 05:43:47 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id E70B44003F; Thu, 16 Sep 2021 05:43:46 +0200 (CEST) Received: from mail-io1-f54.google.com (mail-io1-f54.google.com [209.85.166.54]) by mails.dpdk.org (Postfix) with ESMTP id 840A64003C for ; Thu, 16 Sep 2021 05:43:45 +0200 (CEST) Received: by mail-io1-f54.google.com with SMTP id b200so6200545iof.13 for ; Wed, 15 Sep 2021 20:43:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=lskLF90IQJPb8/oiHD58PyPnuUqdrTgAhyeE/qS2aL8=; b=kiLVHJnM47ONS652VAL8a41SPB844+Ahwd02DR6rXXRT6Fa9Eb3Jhvq/rtFuRQFhFB i/JXq+k0ciuOkVHrL/sJUrjCOljFjqb81AQQNOZjvgNVQTNE/vke0geGNuPOO95Qws2+ Fa1VDjnw6+v+ZzsOWfKtGAxDsk48RsYL0L4ytwxaCT30ZrsoWrOjeqVolhMantafAmtc cLAxbSxHfm8DxaGsKUrPaowzTKG1mBjvBOQ8scHccXLSZejkbtaUs+TfNor4iQDfgHkK GqxjO652M0i1fBpf/of4ewOj6+ZrRkEYjmsN1PKoRLDYjV/7reIG0cuaX9H0rXW9+o2d rNUg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lskLF90IQJPb8/oiHD58PyPnuUqdrTgAhyeE/qS2aL8=; b=RZOJfj00Ry2GV7/1mExf4p3wB+ACDhgBkPo+u51icwjnuPM8+ztkdbWF2cZHDAAX/x +acv2wM75dozu8IJJuAe+nIMh7ElbzBe1fameUsS67HgDAqgdCNfs8JDEnNzJNLf2Hm/ yu4J/yjFQN7fw8UoF+eQDIgiL1vXmqHiUZBzvAko7XlqGCGFPtnrVNVRBnrccPOUJMnV rz/ZANg1X/7587zclG1Z93666ir3+kV6gebBC4ZDn+7ItdbMnLnNcT3JBwxHgJ4EhXdr qgGPlpq/v8fLxPpsXOmL86oiBCFtC5ItCqnD/g4ks+7VX0PKh9/5WwWeqv02neNEpKNU 9kqQ== X-Gm-Message-State: AOAM531o5twV0POxyE+mg/15hGD55jdJtln8g1sl3h4uzJXPRc/tDV03 cTRNV3xV+TPWNKqGYtJNLlsTzq9/MuzEb/cpzsE= X-Google-Smtp-Source: ABdhPJwiIybNnx00/oWGs6CVDeIBx8ZZN3sJJJukoAnBVw+EskObiASazxuBVJfbS+ootKeVP4Y2m4XMLy+nw1XNv4k= X-Received: by 2002:a05:6638:1696:: with SMTP id f22mr2686130jat.15.1631763824868; Wed, 15 Sep 2021 20:43:44 -0700 (PDT) MIME-Version: 1.0 References: <20201211155111.145279-1-bruce.richardson@intel.com> In-Reply-To: From: Jerin Jacob Date: Thu, 16 Sep 2021 09:13:18 +0530 Message-ID: To: David Christensen Cc: Bruce Richardson , dpdk-dev , Luca Boccassi , David Marchand , ian.stokes@intel.com, Ilya Maximets , Jerin Jacob , Ruifeng Wang , Honnappa Nagarahalli , "Ananyev, Konstantin" , Ferruh Yigit Content-Type: text/plain; charset="UTF-8" Subject: Re: [dpdk-dev] [RFC PATCH] build/pkg-config: remove machine arch flag X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Thu, Sep 16, 2021 at 2:53 AM David Christensen wrote: > > > > On 9/15/21 9:28 AM, Bruce Richardson wrote: > > On Fri, Dec 11, 2020 at 03:51:11PM +0000, Bruce Richardson wrote: > >> Traditionally any apps built using DPDK had to support the same > >> instruction sets as supported when the DPDK SDK itself was built, since > >> that was "leaked" through to the end-app and DPDK headers via > >> RTE_MACHINE_CPUFLAG_* values. Therefore, when converting over to meson > >> for app build correctness the "-march=" flag was included in the > >> pkg-config cflags output. > >> > >> However, since the DPDK-specific CPU flags are now obsolete, and we > >> instead check directly for compiler-defined flags, we should no longer > >> need to force the exact same architecture match in all cases. To > >> faciliate such flexibility, a new pkg_config_machine_args array - which > >> defaults to the existing machine_args array has been defined. The > >> individual architectures - x86, arm and ppc - can choose if and how to > >> override this value themselves. > >> > >> For x86, since SSE4.2 is the minimum instruction-set level needed to run > >> DPDK, and since some header files assume that minimum level of > >> instruction set support, we override the "-march=" value with "-msse4" > >> for the pkg-config file. This allows end applications to set their own > >> "march" value while still ensuring valid DPDK compilation. > >> > >> Signed-off-by: Bruce Richardson > >> --- > >> > >> CC: Jerin Jacob > >> CC: Ruifeng Wang > >> CC: Honnappa Nagarahalli > >> CC: David Christensen for > >> Feedback requested from ARM and PPC maintainers as to this change > >> and what flags, if any, need to be in the .pc file for DPDK on such > >> platforms. For example - is setting 'pkg_config_machine_args' to > >> 'machine_args' by default necessary behaviour? > >> > > > > Ping for further thoughts or input on this patch. Armv8 has dedicated config(taken least cpu flags which supports all armv8) for this purpose config/arm/arm64_armv8_linux_gcc. So this change looks good to me. @Ruifeng Wang (Arm Technology China) Any comments? > > On initial inspection I don't see any additional value for PPC systems. > Selection of a CPU through -mcpu implies a full ISA for that CPU, > including things like vector extensions, at least with respect to the > minimum supported POWER8 CPU (ISA 2.07) and later ISAs. The values of > machine_args and pkg_config_machine_args should be identical in all > cases I can think of. > > If a third party OpenPOWER CPU comes along some time in the future then > the requirements may change. > > Dave