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 E8DA1C10DCE for ; Thu, 12 Mar 2020 13:52:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0BD920739 for ; Thu, 12 Mar 2020 13:52:06 +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="q6dBvJDT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727573AbgCLNwF (ORCPT ); Thu, 12 Mar 2020 09:52:05 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:57002 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727498AbgCLNvm (ORCPT ); Thu, 12 Mar 2020 09:51:42 -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=v9xr6HmXi0QTp0R2R+PP22HJYiYCg07/b2WV9INOx7w=; b=q6dBvJDTVBFxLntf5HP0Mqu4H6 zbnYyoLYU2LMivn5NhGn3Gr5TexWExlz+mR0V5BgXG9neI1GPwaqdZ0I3H/DxZ/wvCUxP0x6OhZU5 1s7sNB+n6dtGR8nfDVl8fyeFtdr7KI/dnJ+huPv/5Ho0pNSEJOeuARkjdXQnUQLSFRHSpva1rSWGO YHpk/wlcA3IDhgwdcL7tBNjxbnQU0a6w6iX2I83dbycTsY7wjAo9sEjcoeUWBcTakcSMB+DE8Gr0Z Sh/t6lX4p4V6Kg2YnmDUw7XKPsGtL5BAfRgH7AlmzpVQeKFz9jrFEvhcn+u+JWCactObBE/407Ny9 cA4jmpMw==; 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 1jCOFP-0006Wu-EZ; Thu, 12 Mar 2020 13:51:39 +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 5EEF4307112; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 505B72B92DA0C; Thu, 12 Mar 2020 14:51:34 +0100 (CET) Message-Id: <20200312135042.346616828@infradead.org> User-Agent: quilt/0.65 Date: Thu, 12 Mar 2020 14:41:23 +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 16/16] objtool: Optimize !vmlinux.o again 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 When doing kbuild tests to see if the objtool changes affected those I found that there was a measurable regression: pre post real 1m13.594 1m16.488s user 34m58.246s 35m23.947s sys 4m0.393s 4m27.312s Perf showed that for small files the increased hash-table sizes were a measurable difference. Since we already have -l "vmlinux" to distinguish between the modes, make it also use a smaller portion of the hash-tables. This flips it into a small win: real 1m14.143s user 34m49.292s sys 3m44.746s Signed-off-by: Peter Zijlstra (Intel) --- tools/objtool/elf.c | 40 ++++++++++++++++++++++++++++------------ tools/objtool/elf.h | 4 ++-- 2 files changed, 30 insertions(+), 14 deletions(-) --- a/tools/objtool/elf.c +++ b/tools/objtool/elf.c @@ -27,6 +27,21 @@ static inline u32 str_hash(const char *s return jhash(str, strlen(str), 0); } +static inline int elf_hash_bits(void) +{ + return vmlinux ? 20 : 16; +} + +static inline void elf_hash_add(struct hlist_head *table, struct hlist_node *node, u32 key) +{ + hlist_add_head(node, &table[hash_32(key, elf_hash_bits())]); +} + +static void elf_hash_init(struct hlist_head *table) +{ + __hash_init(table, 1U << elf_hash_bits()); +} + static void rb_add(struct rb_root *tree, struct rb_node *node, int (*cmp)(struct rb_node *, const struct rb_node *)) { @@ -300,8 +315,8 @@ static int read_sections(struct elf *elf } sec->len = sec->sh.sh_size; - hash_add(elf->section_hash, &sec->hash, sec->idx); - hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name)); + elf_hash_add(elf->section_hash, &sec->hash, sec->idx); + elf_hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name)); } if (stats) @@ -387,8 +402,8 @@ static int read_symbols(struct elf *elf) entry = &sym->sec->symbol_list; 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)); + elf_hash_add(elf->symbol_hash, &sym->hash, sym->idx); + elf_hash_add(elf->symbol_name_hash, &sym->name_hash, str_hash(sym->name)); } if (stats) @@ -497,7 +512,7 @@ static int read_relas(struct elf *elf) } list_add_tail(&rela->list, &sec->rela_list); - hash_add(elf->rela_hash, &rela->hash, rela_hash(rela)); + elf_hash_add(elf->rela_hash, &rela->hash, rela_hash(rela)); nr_rela++; } max_rela = max(max_rela, nr_rela); @@ -524,15 +539,16 @@ struct elf *elf_read(const char *name, i perror("malloc"); return NULL; } - memset(elf, 0, sizeof(*elf)); + memset(elf, 0, offsetof(struct elf, sections)); - hash_init(elf->symbol_hash); - hash_init(elf->symbol_name_hash); - hash_init(elf->section_hash); - hash_init(elf->section_name_hash); - hash_init(elf->rela_hash); INIT_LIST_HEAD(&elf->sections); + elf_hash_init(elf->symbol_hash); + elf_hash_init(elf->symbol_name_hash); + elf_hash_init(elf->section_hash); + elf_hash_init(elf->section_name_hash); + elf_hash_init(elf->rela_hash); + elf->fd = open(name, flags); if (elf->fd == -1) { fprintf(stderr, "objtool: Can't open '%s': %s\n", @@ -671,7 +687,7 @@ struct section *elf_create_section(struc shstrtab->len += strlen(name) + 1; shstrtab->changed = true; - hash_add(elf->section_hash, &sec->hash, sec->idx); + elf_hash_add(elf->section_hash, &sec->hash, sec->idx); return sec; } --- a/tools/objtool/elf.h +++ b/tools/objtool/elf.h @@ -81,8 +81,8 @@ struct elf { 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); + DECLARE_HASHTABLE(section_hash, 20); + DECLARE_HASHTABLE(section_name_hash, 20); DECLARE_HASHTABLE(rela_hash, 20); };