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 923CEC1975A for ; Thu, 12 Mar 2020 13:52:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 606AD2071B for ; Thu, 12 Mar 2020 13:52:32 +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="hQJ7wqr1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727678AbgCLNwb (ORCPT ); Thu, 12 Mar 2020 09:52:31 -0400 Received: from merlin.infradead.org ([205.233.59.134]:46844 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727467AbgCLNvl (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=merlin.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=IT3R/wnPJR6ANDGqxsHfySvScSEJgnsZS5Al5B69paY=; b=hQJ7wqr13PtnKd4paDMXZhysg8 s0k3Cl39ojI9FCFVFT6hxi2O6xk6GvD+S5ALAB2DPeN9nM4diJEDpNFrH2i0MzuFWFnjFkSlrgHah 9m9lBkWobcIbxp46vvr1HLd9Ljk2tqqjEUjzBySy3+e6a10hltQwlOhWel2vnk7XfMcxkUt4+k4HK S19wO+SJmWvuWFD4XXTh4Ea19YQ+iduU3vtZHF0/ZXiAz4pf4+a5dYQTILRuThVQg9uqJXekE/3va TWF4cJaIG7RHZlaZ/by1BfKvNMFR0jwP0rBXt2l27xDQ66iN3EzQcvdXW8Yu85mBB2RhYtR+MXcSi kCVHxotg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jCOFO-0003Ae-BL; 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 5079D30705A; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 3C1542B7403AA; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Message-Id: <20200312135042.053418319@infradead.org> User-Agent: quilt/0.65 Date: Thu, 12 Mar 2020 14:41:18 +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 11/16] objtool: Optimize find_symbol_by_name() 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 Perf showed that find_symbol_by_name() takes time; add a symbol name hash. This shaves another second off of objtool on vmlinux.o runtime, down to 15 seconds. Signed-off-by: Peter Zijlstra (Intel) --- tools/objtool/elf.c | 10 +++++----- tools/objtool/elf.h | 2 ++ 2 files changed, 7 insertions(+), 5 deletions(-) --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -134,13 +134,11 @@ struct symbol *find_symbol_by_offset(str struct symbol *find_symbol_by_name(struct elf *elf, const char *name) { - struct section *sec; struct symbol *sym; - list_for_each_entry(sec, &elf->sections, list) - list_for_each_entry(sym, &sec->symbol_list, list) - if (!strcmp(sym->name, name)) - return sym; + hash_for_each_possible(elf->symbol_name_hash, sym, name_hash, str_hash(name)) + if (!strcmp(sym->name, name)) + return sym; return NULL; } @@ -365,6 +363,7 @@ static int read_symbols(struct elf *elf) list_add(&sym->list, entry); hash_add(elf->symbol_hash, &sym->hash, sym->idx); + hash_add(elf->symbol_name_hash, &sym->name_hash, str_hash(sym->name)); } if (stats) @@ -503,6 +502,7 @@ struct elf *elf_read(const char *name, i memset(elf, 0, sizeof(*elf)); hash_init(elf->symbol_hash); + hash_init(elf->symbol_name_hash); hash_init(elf->section_hash); hash_init(elf->section_name_hash); INIT_LIST_HEAD(&elf->sections); --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -47,6 +47,7 @@ struct symbol { struct list_head list; struct rb_node node; struct hlist_node hash; + struct hlist_node name_hash; GElf_Sym sym; struct section *sec; char *name; @@ -77,6 +78,7 @@ struct elf { char *name; struct list_head sections; DECLARE_HASHTABLE(symbol_hash, 20); + DECLARE_HASHTABLE(symbol_name_hash, 20); DECLARE_HASHTABLE(section_hash, 16); DECLARE_HASHTABLE(section_name_hash, 16); };