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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8559FEB64D8 for ; Wed, 14 Jun 2023 16:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235887AbjFNQhl (ORCPT ); Wed, 14 Jun 2023 12:37:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235460AbjFNQhO (ORCPT ); Wed, 14 Jun 2023 12:37:14 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58A8410E9; Wed, 14 Jun 2023 09:37:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E85676409C; Wed, 14 Jun 2023 16:37:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2413C433C0; Wed, 14 Jun 2023 16:37:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686760629; bh=Bs+EyfsO2p9fJ/uqqvy28thI6wPfslvdFWG010Lc/Ns=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YefGG52yVCQf3IypRiZPtyZ7PvmCO+Kdc2xodNzcw7+v5J6HaCpn0lu1wYeVgv6B+ mj9gLO4vnTF99DdR2O/wyhsXvhnIm5KcwCJYE7ooevgccwXczE/2FNEYu2nCX6wPFt +/yrM8HKUUV2gLoLaApRLTjJF7UE54oDIVF3nJLckn8SaO8CCR2DqFIaOBlzvYOW/5 hZ+eteDS3bzfgf7ql3+U1DEHXs4SrIy7t53ljQcXEi3JyVXeyL12JDz4fFg3SHkfUH 89LHGk6N95J2D7jn1cAXKKUyBrX/z0bL1yPQdJL8Usn7k+hhhZsvRPUDRabsB6J2qh cAEiWwrW7Gc0g== Date: Thu, 15 Jun 2023 00:25:49 +0800 From: Jisheng Zhang To: Palmer Dabbelt Cc: Paul Walmsley , aou@eecs.berkeley.edu, Arnd Bergmann , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH v2 0/4] riscv: enable HAVE_LD_DEAD_CODE_DATA_ELIMINATION Message-ID: References: <20230523165502.2592-1-jszhang@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On Wed, Jun 14, 2023 at 07:49:17AM -0700, Palmer Dabbelt wrote: > On Tue, 23 May 2023 09:54:58 PDT (-0700), jszhang@kernel.org wrote: > > 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(-) > > Do you have a base commit for this? It's not applying to 6.4-rc1 and the > patchwork bot couldn't find one either. Hi Palmer, Commit 3b90b09af5be ("riscv: Fix orphan section warnings caused by kernel/pi") touches vmlinux.lds.S, so to make the merge easy, this series is based on 6.4-rc2. Thanks