From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2DFAC169C4 for ; Fri, 8 Feb 2019 06:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 66CA521916 for ; Fri, 8 Feb 2019 06:07:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="l6QAn2pG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727085AbfBHGHm (ORCPT ); Fri, 8 Feb 2019 01:07:42 -0500 Received: from mail-ed1-f66.google.com ([209.85.208.66]:37838 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726524AbfBHGHm (ORCPT ); Fri, 8 Feb 2019 01:07:42 -0500 Received: by mail-ed1-f66.google.com with SMTP id g4so1843591eds.4; Thu, 07 Feb 2019 22:07:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=4kEPACT+cGX8sOqnTw34J+1Wi5NSgOceF8oPzUQ/5s0=; b=l6QAn2pGqMp5uCwuPrlHle+YBgBMON1MYpzCw9LEfeY3MUaNqWFKMOZb/26QjRoVpJ JFEUS4fZgQ5F1jyxhX6oDVaCPtH5ezafmA1FgrQ5k5W39Q+kIpjzYzUrPK6hn/FQZJVJ /EY00ygar3sIpO0TXj2UlamkebfD3pHIbZCnnyIBQmnOUmBxEUY6Sj1JL+k68AQEomAg xSxHVfTSPhTYwkshUtTwi9ls85+0I6y92uedoqWWh6ezBbxNXF7vXraZ1g1oDUERo0pw ec8wP6j7+R+IARX+TIKAeQJ3jl9Y70CmPDOGnJU3+ouGW1a5kTeGAzafBxeSXKIeRZS0 KYJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=4kEPACT+cGX8sOqnTw34J+1Wi5NSgOceF8oPzUQ/5s0=; b=INzIRAB9u0IzzsWqR14Lh3QzX8KhJtZfR8KkQhSDvwmTZ/NcrbfEbFBkoDjZvxAwjB erigLhjP2H+kdBuPVoxnin55cmCV0y8l/MMN+RtMQZGRX3WPWZlO4DvPzzfzJGu3v0ON 54NWU73EmcaaaqJG73cqjk47E7gt3UGa7rYJIlPjjfn8+mo60liklcg8nJ206O3H1ITk rN+ySZwRF2kNkaMfbL6KepO3QPIU884N6gcpw0Qf+eeX4gJl+inEawc3XZTZYvc1cnGL rZjkMQ6zg4qx6iGZxy4+LqG7aqZizmQ8ylLl9EAz4+Yqf4ISEPOODa4oBLh7BAuHJJwz d+gg== X-Gm-Message-State: AHQUAua0lajW/j7hkczdrhQPTxsPsUJUjdvb6LcpbbHEj3+lWyzBngRX HSqs1TTAaMKcw89sP5XRAY8= X-Google-Smtp-Source: AHgI3IYdJzqWymmvYzdd8VHzR7klzkuMKpuNzm5Rjl4eDKAoE5GK/mR2pA38t5nTaV4gpQRnz9zEvg== X-Received: by 2002:aa7:d802:: with SMTP id v2mr10213253edq.225.1549606060207; Thu, 07 Feb 2019 22:07:40 -0800 (PST) Received: from archlinux-ryzen ([2a01:4f9:2a:1fae::2]) by smtp.gmail.com with ESMTPSA id z9sm378169edr.61.2019.02.07.22.07.39 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 07 Feb 2019 22:07:39 -0800 (PST) Date: Thu, 7 Feb 2019 23:07:37 -0700 From: Nathan Chancellor To: ndesaulniers@google.com Cc: yamada.masahiro@socionext.com, Rui Ueyama , Michal Marek , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/4] Makefile: lld: set -O2 linker flag when linking with LLD Message-ID: <20190208060737.GA12027@archlinux-ryzen> References: <20190207220155.81351-1-ndesaulniers@google.com> <20190207220155.81351-4-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190207220155.81351-4-ndesaulniers@google.com> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 07, 2019 at 02:01:52PM -0800, ndesaulniers@google.com wrote: > -O2 enables tail merging of string table strings. > > For arm64: > 0.34% size improvement with lld -O2 over lld for vmlinux. > 3.30% size improvement with lld -O2 over lld for Image.lz4-dtb. > > Link: https://github.com/ClangBuiltLinux/linux/issues/343 > Suggested-by: Rui Ueyama > Suggested-by: Nathan Chancellor > Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor > --- > Makefile | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/Makefile b/Makefile > index 6307c17259ea..c07208ec49d4 100644 > --- a/Makefile > +++ b/Makefile > @@ -718,6 +718,10 @@ else > KBUILD_CFLAGS += -Wno-unused-but-set-variable > endif > > +ifdef CONFIG_LD_IS_LLD > +KBUILD_LDFLAGS += -O2 > +endif > + > KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable) > ifdef CONFIG_FRAME_POINTER > KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls > -- > 2.20.1.791.gb4d0f1c61a-goog >