From patchwork Fri Feb 12 21:16:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bill Wendling X-Patchwork-Id: 12086097 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham 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 2508BC433E0 for ; Fri, 12 Feb 2021 21:17:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D178D64E08 for ; Fri, 12 Feb 2021 21:17:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229796AbhBLVRE (ORCPT ); Fri, 12 Feb 2021 16:17:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbhBLVRD (ORCPT ); Fri, 12 Feb 2021 16:17:03 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B11A3C0613D6 for ; Fri, 12 Feb 2021 13:16:22 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id 127so899656ybc.19 for ; Fri, 12 Feb 2021 13:16:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=ZEMW0Z2ejWn7QhiizYeAVctQKIuWplEIADwwg0z3zW4=; b=dLlVaK20xbUOQhgD4S9zcRXRu6cwDybcW7l7MSWDTC4qlXJBZBnvpHN4+vRwv1Znen 3lR5c3ZK7rJ3/dN20W8oMuCdO1lE7SRV7E6bCmxai9vNWLrOslhWj0+2bRfcXeD2i4ls QGwYlpBcZy+/Ld6ft0yYQxS5vsNcU1pJqxLz19e1b2AWf+a5EDvTmZR6Ov4OZVc9MI8A /jMrTzurHgZk9PiVO6dvtabEW/piBs0tjSJmA5BbHThr7yjN7HGOU8LhFMLaelPvMGXz 6wg+57awmV20LWTCYNTemhDhTmWCPIi4HUjQhqgk8KdY3LNbOwTHTw8bdbT/kQ8E6982 mJYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=ZEMW0Z2ejWn7QhiizYeAVctQKIuWplEIADwwg0z3zW4=; b=qH/P9AatBSTKCYo/x95sMhhil7zFchhPn2MPnRg8gAmYuz8YgFCIm7WdDASxTXEf4x wBi2CHHhF6M+FoJv0p0bdAKWV128+86eQu5nzxf/7gjjukGYVQ80nxrL//Kk+EpPzLYO Px5quaBmJCw0EdsgO3OBdCpXXcqCk2PkHIJ2GdfNgIb9EpwAkLB2951kY7NIDM3dqvfv csHVC8xsnwQtR7/WGnQITTXpCbHSSAFcgZwcBDcet1cc4PN66jMkAgzwr9pgIGOmer0u fvdiJb4aurF96BpfCN3LgMYDorhbHxq7RSIChMf/eiVKQJkiJ9fVmhZ36hawPjlnxFs1 8pxQ== X-Gm-Message-State: AOAM531CmCvakgKeW021P+Sy4n+tM/RPskh7sTUdxUeUuGgKipVyxlVn M/RZBV4hENQ3WDjab3ETFujwrcNh X-Google-Smtp-Source: ABdhPJx6GM6dIf3SKO0QQJAu4+rc7JMZ4Yv0ppGEbzLIRcfxe/2nkEad17PnW9hAAqbO7BO7Cq6HUuXJ9A== Sender: "morbo via sendgmr" X-Received: from fawn.svl.corp.google.com ([2620:15c:2cd:202:ed1b:1611:4b90:c2e9]) (user=morbo job=sendgmr) by 2002:a25:9a89:: with SMTP id s9mr6499666ybo.407.1613164581980; Fri, 12 Feb 2021 13:16:21 -0800 (PST) Date: Fri, 12 Feb 2021 13:16:07 -0800 In-Reply-To: <20210212211607.2890660-1-morbo@google.com> Message-Id: <20210212211607.2890660-2-morbo@google.com> Mime-Version: 1.0 References: <20210212211607.2890660-1-morbo@google.com> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog Subject: [RFC PATCH 1/1] dwarf_loader: have all CUs use a single hash table From: Bill Wendling To: dwarves@vger.kernel.org, bpf@vger.kernel.org Cc: arnaldo.melo@gmail.com, Bill Wendling Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-State: RFC In some instances, e.g. with clang's LTO, a DWARF compilation units may reference tags in other CUs. This presents us with a "chicken and egg" problem, where in order to properly process on CU we need access to the tags in all CUs. This increases the runtime by ~28% (from 11.11s to 14.27s). Signed-off-by: Bill Wendling --- dwarf_loader.c | 45 +++++++++++++++++++++++++++++++++------------ 1 file changed, 33 insertions(+), 12 deletions(-) diff --git a/dwarf_loader.c b/dwarf_loader.c index b73d786..2b0d619 100644 --- a/dwarf_loader.c +++ b/dwarf_loader.c @@ -102,7 +102,7 @@ static void dwarf_tag__set_spec(struct dwarf_tag *dtag, dwarf_off_ref spec) *(dwarf_off_ref *)(dtag + 1) = spec; } -#define HASHTAGS__BITS 15 +#define HASHTAGS__BITS 16 #define HASHTAGS__SIZE (1UL << HASHTAGS__BITS) #define obstack_chunk_alloc malloc @@ -117,21 +117,42 @@ static void *obstack_zalloc(struct obstack *obstack, size_t size) return o; } +/* The tags and types hashes used by all "dwarf_cu" objects. */ +struct dwarf_cu_hash { + struct hlist_head tags[HASHTAGS__SIZE]; + struct hlist_head types[HASHTAGS__SIZE]; +}; + struct dwarf_cu { - struct hlist_head hash_tags[HASHTAGS__SIZE]; - struct hlist_head hash_types[HASHTAGS__SIZE]; + struct dwarf_cu_hash *hashes; struct obstack obstack; struct cu *cu; struct dwarf_cu *type_unit; }; +static struct dwarf_cu_hash *dwarf_cu__init_hashes(void) +{ + static struct dwarf_cu_hash *hashes = NULL; + + if (!hashes) { + unsigned int i; + + hashes = malloc(sizeof(struct dwarf_cu_hash)); + if (!hashes) + return NULL; + + for (i = 0; i < HASHTAGS__SIZE; ++i) { + INIT_HLIST_HEAD(&hashes->tags[i]); + INIT_HLIST_HEAD(&hashes->types[i]); + } + } + + return hashes; +} + static void dwarf_cu__init(struct dwarf_cu *dcu) { - unsigned int i; - for (i = 0; i < HASHTAGS__SIZE; ++i) { - INIT_HLIST_HEAD(&dcu->hash_tags[i]); - INIT_HLIST_HEAD(&dcu->hash_types[i]); - } + dcu->hashes = dwarf_cu__init_hashes(); obstack_init(&dcu->obstack); dcu->type_unit = NULL; } @@ -166,8 +187,8 @@ static void cu__hash(struct cu *cu, struct tag *tag) { struct dwarf_cu *dcu = cu->priv; struct hlist_head *hashtable = tag__is_tag_type(tag) ? - dcu->hash_types : - dcu->hash_tags; + dcu->hashes->types : + dcu->hashes->tags; hashtags__hash(hashtable, tag->priv); } @@ -179,7 +200,7 @@ static struct dwarf_tag *dwarf_cu__find_tag_by_ref(const struct dwarf_cu *cu, if (ref->from_types) { return NULL; } - return hashtags__find(cu->hash_tags, ref->off); + return hashtags__find(cu->hashes->tags, ref->off); } static struct dwarf_tag *dwarf_cu__find_type_by_ref(const struct dwarf_cu *dcu, @@ -193,7 +214,7 @@ static struct dwarf_tag *dwarf_cu__find_type_by_ref(const struct dwarf_cu *dcu, return NULL; } } - return hashtags__find(dcu->hash_types, ref->off); + return hashtags__find(dcu->hashes->types, ref->off); } extern struct strings *strings;