From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Date: Sun, 21 Dec 2014 22:05:12 +0100
Subject: [Buildroot] [PATCH] toolchain: get rid of -pipe from
 optimisations
In-Reply-To: <1419166825-25133-1-git-send-email-yann.morin.1998@free.fr>
References: <1419166825-25133-1-git-send-email-yann.morin.1998@free.fr>
Message-ID: <20141221220512.14fe5139@free-electrons.com>
List-Id: <buildroot.busybox.net>
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To: buildroot@busybox.net

Dear Yann E. MORIN,

On Sun, 21 Dec 2014 14:00:25 +0100, Yann E. MORIN wrote:
> -pipe is causing some build failures in Linux kernel >= 3.17.
> 
> Also, nowadays, using -pipe does not gain as much as it used to back in
> the days:
> 
> Measurements made with a 3.16.7 Linux kernel:
>     make linux-depends
>     time sh -c 'make linux-build >/dev/null 2>&1'
> 
> Without -pipe:
>     716.32user 54.44system 3:42.12elapsed 346%CPU
>     721.22user 54.47system 3:41.81elapsed 349%CPU
>     722.44user 54.00system 3:42.13elapsed 349%CPU
>     721.03user 53.81system 3:41.92elapsed 349%CPU
>     713.21user 53.63system 3:40.51elapsed 347%CPU
>     706.67user 52.42system 3:38.40elapsed 347%CPU
>     714.40user 53.18system 3:40.16elapsed 348%CPU
>     706.01user 53.09system 3:37.87elapsed 348%CPU
>     705.98user 53.01system 3:38.03elapsed 348%CPU
>     714.17user 53.55system 3:39.98elapsed 348%CPU
> Average:                   3:40.29elapsed
> 
> With -pipe:
>     720.13user 53.90system 3:41.98elapsed 348%CPU
>     713.38user 53.69system 3:40.44elapsed 347%CPU
>     711.60user 52.81system 3:39.06elapsed 348%CPU
>     708.66user 53.09system 3:38.59elapsed 348%CPU
>     711.76user 53.00system 3:38.48elapsed 350%CPU
>     717.85user 53.97system 3:41.77elapsed 348%CPU
>     716.77user 53.77system 3:40.91elapsed 348%CPU
>     717.48user 53.65system 3:41.24elapsed 348%CPU
>     721.44user 55.67system 3:43.45elapsed 347%CPU
>     724.61user 55.63system 3:43.35elapsed 349%CPU
> Average:                   3:40.93elapsed
> 
> The delta is well in the measurement noise.
> 
> Just get rid of it.
> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> Cc: Romain Naour <romain.naour@openwide.fr>
> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
> ---
>  toolchain/toolchain-common.in | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com