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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 D1BCEC4CECE for ; Thu, 12 Mar 2020 13:52:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A267920739 for ; Thu, 12 Mar 2020 13:52:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="XpsTVoSD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727500AbgCLNvm (ORCPT ); Thu, 12 Mar 2020 09:51:42 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56994 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727455AbgCLNvl (ORCPT ); Thu, 12 Mar 2020 09:51:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=f6GYA/xEKuTMRyLmm4biFIv2SwmvPjDC5cbmzAzDbPM=; b=XpsTVoSDB1qeNQ108Z5FnaXYpg NUw6lnyfOWkMeEu0qQN/FO3kVpn4kk/ASTlMdUJsYpXOUbsjAGhQrh+O9tHejlXFFNv72PYi8Ad7F VaD7NFpSrzXpOkxAb/MltaSSTnb/uvasFZoWVsgpMEdndJtROauhtEQ2PuIhZ2xiicZXl/svgThuZ 5ZicBZ+1r6/zKWM5xk6qmCiraGzjsVmBgcuXNHqxZ26bsJKr8qha/9+lHc1KNsA61LKpBTCapvaNr DLbL7/zW0AOTfY5AZWV9Ch5ypDnFSrgE9hl8bKzTWMYmv3Ezd4C622eC4dunN4qGgMG9dktvYgSAz SAX49gIQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCOFN-0006Wa-Rz; Thu, 12 Mar 2020 13:51:38 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 429B4305E21; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 183F12B92DA0C; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Message-Id: <20200312135041.699859794@infradead.org> User-Agent: quilt/0.65 Date: Thu, 12 Mar 2020 14:41:12 +0100 From: Peter Zijlstra To: tglx@linutronix.de, jpoimboe@redhat.com Cc: linux-kernel@vger.kernel.org, x86@kernel.org, peterz@infradead.org Subject: [RFC][PATCH 05/16] objtool: Optimize find_symbol_by_index() References: <20200312134107.700205216@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The symbol index is object wide, not per section, so it makes no sense to have the symbol_hash be part of the section object. By moving it to the elf object we avoid the linear sections iteration. This reduces the runtime of objtool on vmlinux.o from over 3 hours (I gave up) to a few minutes. The defconfig vmlinux.o has around 20k sections. Signed-off-by: Peter Zijlstra (Intel) --- tools/objtool/elf.c | 14 ++++++-------- tools/objtool/elf.h | 3 +-- 2 files changed, 7 insertions(+), 10 deletions(-) --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -46,13 +46,11 @@ static struct section *find_section_by_i static struct symbol *find_symbol_by_index(struct elf *elf, unsigned int idx) { - struct section *sec; struct symbol *sym; - list_for_each_entry(sec, &elf->sections, list) - hash_for_each_possible(sec->symbol_hash, sym, hash, idx) - if (sym->idx == idx) - return sym; + hash_for_each_possible(elf->symbol_hash, sym, hash, idx) + if (sym->idx == idx) + return sym; return NULL; } @@ -156,7 +154,6 @@ static int read_sections(struct elf *elf INIT_LIST_HEAD(&sec->symbol_list); INIT_LIST_HEAD(&sec->rela_list); hash_init(sec->rela_hash); - hash_init(sec->symbol_hash); list_add_tail(&sec->list, &elf->sections); @@ -289,7 +286,8 @@ static int read_symbols(struct elf *elf) } sym->alias = alias; list_add(&sym->list, entry); - hash_add(sym->sec->symbol_hash, &sym->hash, sym->idx); + + hash_add(elf->symbol_hash, &sym->hash, sym->idx); } /* Create parent/child links for any cold subfunctions */ @@ -415,6 +413,7 @@ struct elf *elf_read(const char *name, i } memset(elf, 0, sizeof(*elf)); + hash_init(elf->symbol_hash); INIT_LIST_HEAD(&elf->sections); elf->fd = open(name, flags); @@ -476,7 +475,6 @@ struct section *elf_create_section(struc INIT_LIST_HEAD(&sec->symbol_list); INIT_LIST_HEAD(&sec->rela_list); hash_init(sec->rela_hash); - hash_init(sec->symbol_hash); list_add_tail(&sec->list, &elf->sections); --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -27,7 +27,6 @@ struct section { struct list_head list; GElf_Shdr sh; struct list_head symbol_list; - DECLARE_HASHTABLE(symbol_hash, 8); struct list_head rela_list; DECLARE_HASHTABLE(rela_hash, 16); struct section *base, *rela; @@ -71,7 +70,7 @@ struct elf { int fd; char *name; struct list_head sections; - DECLARE_HASHTABLE(rela_hash, 16); + DECLARE_HASHTABLE(symbol_hash, 20); };