Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933812Ab3D3U4J (ORCPT ); Tue, 30 Apr 2013 16:56:09 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:40962 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932355Ab3D3U4F (ORCPT ); Tue, 30 Apr 2013 16:56:05 -0400 Date: Tue, 30 Apr 2013 13:56:02 -0700 From: Andrew Morton To: Kyungsik Lee Cc: Russell King , "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, x86@kernel.org, celinux-dev@lists.celinuxforum.org, Nicolas Pitre , David Sterba , Nitin Gupta , Joe Millenbach , Thomas Gleixner , Michal Marek , hyojun.im@lge.com, chan.jeong@lge.com, raphael.andy.lee@gmail.com Subject: Re: [PATCH v3 -next 3/5] arm: Add support for LZ4-compressed kernel Message-Id: <20130430135602.2aa0d3b4ec392bf83a9b64d0@linux-foundation.org> In-Reply-To: <1362484056-9778-4-git-send-email-kyungsik.lee@lge.com> References: <1362484056-9778-1-git-send-email-kyungsik.lee@lge.com> <1362484056-9778-4-git-send-email-kyungsik.lee@lge.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1011 Lines: 33 On Tue, 5 Mar 2013 20:47:34 +0900 Kyungsik Lee wrote: > This patch integrates the LZ4 decompression code to the arm pre-boot code. > And it depends on two patchs below > > lib: Add support for LZ4-compressed kernel > decompressor: Add LZ4 decompressor module > > ... > > - Apply CFLAGS, -Os to decompress.o to improve decompress > performance during boot-up process > > ... > > --- a/arch/arm/boot/compressed/Makefile > +++ b/arch/arm/boot/compressed/Makefile > @@ -24,6 +24,9 @@ endif > AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET) > HEAD = head.o > OBJS += misc.o decompress.o > +ifeq ($(CONFIG_KERNEL_LZ4),y) > +CFLAGS_decompress.o := -Os > +endif Surprised. You found that -Os produces faster code than -O2? Details, please? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/