From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
	by inbox.dpdk.org (Postfix) with ESMTP id 6EE2DA2EFC
	for <public@inbox.dpdk.org>; Thu, 19 Sep 2019 17:16:34 +0200 (CEST)
Received: from [92.243.14.124] (localhost [127.0.0.1])
	by dpdk.org (Postfix) with ESMTP id 2AE201F111;
	Thu, 19 Sep 2019 17:16:34 +0200 (CEST)
Received: from mga17.intel.com (mga17.intel.com [192.55.52.151])
 by dpdk.org (Postfix) with ESMTP id AC2681F110
 for <dev@dpdk.org>; Thu, 19 Sep 2019 17:16:32 +0200 (CEST)
X-Amp-Result: UNKNOWN
X-Amp-Original-Verdict: FILE UNKNOWN
X-Amp-File-Uploaded: False
Received: from orsmga002.jf.intel.com ([10.7.209.21])
 by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384;
 19 Sep 2019 08:16:31 -0700
X-IronPort-AV: E=Sophos;i="5.64,523,1559545200"; d="scan'208";a="199425044"
Received: from bricha3-mobl.ger.corp.intel.com ([10.252.3.193])
 by orsmga002-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384;
 19 Sep 2019 08:16:27 -0700
Date: Thu, 19 Sep 2019 17:16:24 +0200
From: Bruce Richardson <bruce.richardson@intel.com>
To: Ray Kinsella <mdr@ashroe.eu>
Cc: Andrzej Ostruszka <amo@semihalf.com>, dev@dpdk.org,
 Aaron Conole <aconole@redhat.com>, Michael Santana <msantana@redhat.com>,
 Thomas Monjalon <thomas@monjalon.net>,
 John McNamara <john.mcnamara@intel.com>,
 Marko Kovacevic <marko.kovacevic@intel.com>,
 David Hunt <david.hunt@intel.com>,
 Vladimir Medvedkin <vladimir.medvedkin@intel.com>,
 Robert Sanford <rsanford@akamai.com>,
 Erik Gabriel Carrillo <erik.g.carrillo@intel.com>,
 mattias.ronnblom@ericsson.com, stephen@networkplumber.org,
 Andrzej Ostruszka <aostruszka@marvell.com>
Message-ID: <20190919151624.GA1999@bricha3-MOBL.ger.corp.intel.com>
References: <20190917075754.8310-1-amo@semihalf.com>
 <20190917075754.8310-2-amo@semihalf.com>
 <8ba7ce2f-e687-3e1c-c7ab-7749764e80d8@ashroe.eu>
 <dfe9d197-7798-0691-4eb2-fe0df7717e86@semihalf.com>
 <9c54ea43-0965-e3e6-9da2-a85edbe40831@ashroe.eu>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <9c54ea43-0965-e3e6-9da2-a85edbe40831@ashroe.eu>
User-Agent: Mutt/1.11.4 (2019-03-13)
Subject: Re: [dpdk-dev] [PATCH v2 01/10] build: add an option to enable LTO
 build
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Thu, Sep 19, 2019 at 02:28:04PM +0100, Ray Kinsella wrote:
> 
> 
> On 19/09/2019 13:35, Andrzej Ostruszka wrote:
> > On 9/18/19 3:32 PM, Ray Kinsella wrote:
> ...>
> > Compilation time is much longer.  In a normal hack|fix/compile/repeat
> > cycle with "compile" part being simple "make" the link time might be a
> > bit annoying.  So I imagine keeping LTO off for the most part of the dev
> > cycle and then at the end when doing release/cleanup turn LTO on - to
> > either get release build ready or to get some set of warnings that you
> > address before yet another attempt to release build.  
> 
> Well look, I would say a few things.
> 
> 1. I see build times going down dramatically with Meson/Ninja in any case.

In the general case yes, but mainly it helps if you have a large number of
cores. For anyone building in a CI with only a couple of cores, meson+ninja
isn't going to help much.

/Bruce