From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753562AbeCNIVs (ORCPT ); Wed, 14 Mar 2018 04:21:48 -0400 Received: from mail-qt0-f179.google.com ([209.85.216.179]:37111 "EHLO mail-qt0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753057AbeCNIVp (ORCPT ); Wed, 14 Mar 2018 04:21:45 -0400 X-Google-Smtp-Source: AG47ELt6c/7JmPurvX0qHfd2UiZYk85/SurXT54QqTxHfE4YHvMq7nkYirtesNXtirgCB7nnjym3Cf87Zd0P73L2CsA= MIME-Version: 1.0 In-Reply-To: <30abb41033b9670c06a54ff484d61d25d3c6e5cd.1520963956.git-series.kieran.bingham+renesas@ideasonboard.com> References: <30abb41033b9670c06a54ff484d61d25d3c6e5cd.1520963956.git-series.kieran.bingham+renesas@ideasonboard.com> From: Geert Uytterhoeven Date: Wed, 14 Mar 2018 09:21:44 +0100 X-Google-Sender-Auth: 0JwPQGIGTPnFbasHXFuBOOEix1I Message-ID: Subject: Re: [PATCH v2 02/11] media: vsp1: Remove packed attributes from aligned structures To: Kieran Bingham Cc: Laurent Pinchart , Linux Media Mailing List , DRI Development , Linux-Renesas , Mauro Carvalho Chehab , open list Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 13, 2018 at 7:05 PM, Kieran Bingham wrote: > The use of the packed attribute can cause a performance penalty for > all accesses to the struct members, as the compiler will assume that the > structure has the potential to have an unaligned base. > > These structures are all correctly aligned and contain no holes, thus > the attribute is redundant and negatively impacts performance, so we > remove the attributes entirely. > > Signed-off-by: Kieran Bingham Reviewed-by: Geert Uytterhoeven Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds