From patchwork Tue May 30 17:21:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josh Poimboeuf X-Patchwork-Id: 101042 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp2343704vqr; Tue, 30 May 2023 10:30:15 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5eEif9n5AxJseoThKCQ29Pvw7c9eyyRw1KYunOLmOpkP9t2l4E0oRUU4IUF2xSSMqzyOq+ X-Received: by 2002:a17:902:8684:b0:1af:c6d2:287 with SMTP id g4-20020a170902868400b001afc6d20287mr2958148plo.53.1685467815097; Tue, 30 May 2023 10:30:15 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685467815; cv=none; d=google.com; s=arc-20160816; b=r2ZM+n0Yu/qACav4jhXuiVj4hV12KPqJKc5KcKU6xMurKRffeUxoKQsJnAyHGiNre6 d5eVXy6acVVdLHTwZedFmMaZmdLm6Duv89q0qZxgMoTs2ogmRZC0a6uVDV5SsPu66LQv 4mb5BUShPNW7NcPXk+u6lz4LUF+ZZ0AcSimvpFF3Q0ALDfigY8OzvNvd4LlrNbSQl4qj nGe2WCxbvgE3fPLZeePWdUKJIOewj2CzrMLcX5w0MCO4BDGhTcFBDcxYjtUkLC7PQoP/ VUCj7ZX+GIb8geQtfa6oIcPDbslFsHYYLg+PE+BV1pyLJCBNiwc6hsLcmCtZU2th49sv hqWQ== 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 :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=IUgouatdz6Tjrk+/WJxNUTUqMB7kQz9T8hqV6LHVyoA=; b=B+0RgbKn5JjSqVqlYb+xiltMHkoBPcvm260saFNMyqEJG1fbzUWLUYBtjUJLVbrD/X QmAnsfx4B9qWLLbT0FhSMGniw8ZDbptPklwfn8kyjp2hKsu+40rDC8Ku2OEllQ1v1Wpm M7ANSwaxXnee23iwDcL1sMLZb5oBljDaioUTec2Clcp7nGGT/7unLstsVtUkHQJ6g4Xa wKQuc+0cRGCeUDmWkS4BuD6LJ9k7mKOkqShU9HxvnfaEUe/eNHttiYRUl7mpSsZfh7gt Rjyl91CylMp4UO0h7zWo3L8LxOAtAxGq23RInOOUZbDF7+DtBdx4ghwH5U2ZOYk5NOBQ VR2g== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=tmRnWW51; 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 l17-20020a170902f69100b001ab286e740bsi735834plg.328.2023.05.30.10.29.38; Tue, 30 May 2023 10:30:15 -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=tmRnWW51; 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 S233463AbjE3RWx (ORCPT + 99 others); Tue, 30 May 2023 13:22:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233258AbjE3RVo (ORCPT ); Tue, 30 May 2023 13:21:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3404106 for ; Tue, 30 May 2023 10:21:39 -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 BABE8616AF for ; Tue, 30 May 2023 17:21:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60BA8C43321; Tue, 30 May 2023 17:21:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685467299; bh=KD8Lf36i8S8fkl9e26OJy++ossCBPSeuvsfaXWI90DE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tmRnWW51kF+qVvCNHgNioj2opxfXrWksnpanZ9AMj5ePvZzpzLlj6ClrgoIwJTh21 T1cong5ST2Vg2+GZOlz51ko9EoC3dcuhJTdH9w9ZDdFgEqRUA0A/vPt69/8HtrmWqc uihOUcYaaHj6pgnhWPpHUn3yyYVt/rzddmfsdy9o0/QATGQ/2sh+qpE/RYszwCNWg0 TmTYiWG82Ew/7mw63L+7sLqjuDN+TMMQDK/20/GvyFImWRb3fYgBFws8cJNIZtcidg DU3k13QPvoxpCdMwH0cXLaBnwxijXLb9PEnZt53gSLFPeGQ+wkbdQaEQbYIKoxr92+ ve+u+jFFg65TA== From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Miroslav Benes Subject: [PATCH 22/22] objtool: Skip reading DWARF section data Date: Tue, 30 May 2023 10:21:14 -0700 Message-Id: <52a9698835861dd35f2ec35c49f96d0bb39fb177.1685464332.git.jpoimboe@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, 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?1767341099521327022?= X-GMAIL-MSGID: =?utf-8?q?1767341099521327022?= Objtool doesn't use DWARF at all, and the DWARF sections' data take up a lot of memory. Skip reading them. Note this only skips the DWARF base sections, not the rela sections. The relas are needed because their symbol references may need to be reindexed if any local symbols get added by elf_create_symbol(). Also note the DWARF data will eventually be read by libelf anyway, when writing the object file. But that's fine, the goal here is to reduce *peak* memory usage, and the previous patch (which freed insn memory) gave some breathing room. So the allocation gets shifted to a later time, resulting in lower peak memory usage. With allyesconfig + CONFIG_DEBUG_INFO: - Before: peak heap memory consumption: 29.93G - After: peak heap memory consumption: 25.47G Signed-off-by: Josh Poimboeuf --- tools/objtool/elf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c index 54d182ddc4bb..d420b5d2e2b6 100644 --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -300,6 +300,11 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns return find_reloc_by_dest_range(elf, sec, offset, 1); } +static bool is_dwarf_section(struct section *sec) +{ + return !strncmp(sec->name, ".debug_", 7); +} + static int read_sections(struct elf *elf) { Elf_Scn *s = NULL; @@ -350,7 +355,7 @@ static int read_sections(struct elf *elf) return -1; } - if (sec->sh.sh_size != 0) { + if (sec->sh.sh_size != 0 && !is_dwarf_section(sec)) { sec->data = elf_getdata(s, NULL); if (!sec->data) { WARN_ELF("elf_getdata");