From patchwork Tue May 23 16:54:58 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 9747 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp2296852vqo; Tue, 23 May 2023 10:13:47 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ6lxde/iio3tbkZ2t2SXY6G1i0l1IZ85WVNam7j+LwhjX+PxqgZ623i0fEpfjLIgi4I+W5D X-Received: by 2002:a05:6a20:1445:b0:101:a459:bb0d with SMTP id a5-20020a056a20144500b00101a459bb0dmr16600499pzi.2.1684862027338; Tue, 23 May 2023 10:13:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1684862027; cv=none; d=google.com; s=arc-20160816; b=1AyuV0FSL90kDLDqn6X3GAQqblzi65T8rjpHerLrUVUvVqjGebsaTzQol+v80h/eT9 ZFRhrtbg/9jPf7MOZKpbwOv6DnuFdT/o4pafMenzZOjxxJdtNj5+ou5jTm25cAfTKcEv MF4FcfsmrzBD8ayhsLF9TT8bWlLBoJqrOQejzg+RVJhU7puO7+v7Oh12FOGna2r306Q7 kBaPR79Gtr6Hr8HEFIhxO42VeqpSwt3ES4v0+sI5pEexYi1V8Wyp8O1M9Dz4Qb8sU6Cb 9hLLTXiyqnjJOehBSMDpZYDmjWHn2y+WVJBaiAFda+eFPVmFCy1k3WgFdjajJm4FRZ8w 8g1Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:date:subject:cc:to:from:dkim-signature; bh=isRYn9lN6cEAqWClhe0WBzt/RxYyvB9g2enpJeYjAos=; b=yijReQPeHe9ZFhDOtbZiIabOr9aaGMPU0F8MlWYPDO4xTlh1jDSPW090PktUCB3Ifn fIeOVYwHEiREqBPWOW4E4J+Fdhmqrn6YVyezBa2FuiVGHaTdWfARNOPdRouaJn3LaE2/ YWH4mZSglMnHp3U5Gy/tDwH9Z7TksZvlp8IWkuzx0pB6TIZDcclmU29/BkN20C6z2yqj s8NadF4vzI7wBb2JS7rnE7m7ouhAUfzpwmYhfWzJ19bO9IVtMcIJ/oRcU1mkzBYXGxZK kRwLc+A9Wo8Vh772KImreJF1g4aaxZNiNDmaiw1JdUE2gJn+xJh5qQYSdN54/XwXyKDT zx5Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=S9susCoo; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id g9-20020a63fa49000000b00524eef20da6si876483pgk.642.2023.05.23.10.13.32; Tue, 23 May 2023 10:13:47 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=S9susCoo; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237949AbjEWRGR (ORCPT + 99 others); Tue, 23 May 2023 13:06:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237927AbjEWRGP (ORCPT ); Tue, 23 May 2023 13:06:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E2AF8B5; Tue, 23 May 2023 10:06:14 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7F8F862542; Tue, 23 May 2023 17:06:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 466B5C433D2; Tue, 23 May 2023 17:06:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684861573; bh=O4HzR93cVyWgDZI2VtGL8GGS2znNViXwdOo0oYNScmQ=; h=From:To:Cc:Subject:Date:From; b=S9susCoorlA+c7uqs58+sjbap9DCpSH16D6qnZjnn4qMOmF9hDSX7WFNdJoytkDy+ TJAOF76W5AoLfrS0i5hCoGI/Dd1rke+vhNX0Nk8gJIVY0WlzZMymoTxgUTZfJl85+R KIyTvCf2J4alkJKeJs79j190Xw41NQJpUOQ0yA83g5p7kaFcPFUG4KbCXHat1zRwH5 nnh9lg91Ok6B44pGoWtSVRf2v4Qw4oA4czgifYOOZ6gzvb/r6dVwCe8j4qycsXvvj9 neJq4SboSHhxqkNBepoZNv0bgNBgHMVMkc5aFlw1OTddb4KX3ntcqTtic8rQ7HMZPr Sip+jFo6uxigg== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , Arnd Bergmann Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: [PATCH v2 0/4] riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION Date: Wed, 24 May 2023 00:54:58 +0800 Message-Id: <20230523165502.2592-1-jszhang@kernel.org> X-Mailer: git-send-email 2.40.0 MIME-Version: 1.0 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1766705885586457268?= X-GMAIL-MSGID: =?utf-8?q?1766705885586457268?= When trying to run linux with various opensource riscv core on resource limited FPGA platforms, for example, those FPGAs with less than 16MB SDRAM, I want to save mem as much as possible. One of the major technologies is kernel size optimizations, I found that riscv does not currently support HAVE_LD_DEAD_CODE_DATA_ELIMINATION, which passes -fdata-sections, -ffunction-sections to CFLAGS and passes the --gc-sections flag to the linker. This not only benefits my case on FPGA but also benefits defconfigs. Here are some notable improvements from enabling this with defconfigs: nommu_k210_defconfig: text data bss dec hex 1112009 410288 59837 1582134 182436 before 962838 376656 51285 1390779 1538bb after rv32_defconfig: text data bss dec hex 8804455 2816544 290577 11911576 b5c198 before 8692295 2779872 288977 11761144 b375f8 after defconfig: text data bss dec hex 9438267 3391332 485333 13314932 cb2b74 before 9285914 3350052 483349 13119315 c82f53 after patch1 and patch2 are clean ups. patch3 fixes a typo. patch4 finally enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION for riscv. NOTE: Zhangjin Wu firstly sent out a patch to enable dead code elimination for riscv several months ago, I didn't notice it until yesterday. Although it missed some preparations and some sections's keeping, he is the first person to enable this feature for riscv. To ease merging, this series take his patch into my entire series and makes patch4 authored by him after getting his ack to reflect the above fact. Since v1: - collect Reviewed-by, Tested-by tag - Make patch4 authored by Zhangjin Wu, add my co-developed-by tag Jisheng Zhang (3): riscv: move options to keep entries sorted riscv: vmlinux-xip.lds.S: remove .alternative section vmlinux.lds.h: use correct .init.data.* section name Zhangjin Wu (1): riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION arch/riscv/Kconfig | 13 +- arch/riscv/kernel/vmlinux-xip.lds.S | 6 - arch/riscv/kernel/vmlinux.lds.S | 6 +- include/asm-generic/vmlinux.lds.h | 2 +- 4 files changed, 11 insertions(+), 16 deletions(-) Tested-by: Nick Desaulniers # build