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=-13.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 4B0B8C47428 for ; Wed, 30 Sep 2020 04:28:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 083D020B1F for ; Wed, 30 Sep 2020 04:28:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="aO7Ljzad" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725385AbgI3E2T (ORCPT ); Wed, 30 Sep 2020 00:28:19 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:40034 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725801AbgI3E2T (ORCPT ); Wed, 30 Sep 2020 00:28:19 -0400 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 08U4QZ05001869 for ; Tue, 29 Sep 2020 21:28:18 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=mX9KE6mb3xhDNfI80kVyZe5AkD9OP3wbxlF8NxUF65U=; b=aO7Ljzadv3RaiyG6iBYB9AHX/xt15X1qc2hUE4JvIgLjchYoq6vycL2UH/v5Y0wmI0hK mn+2DErQGAJnwJyCy1+H4I8KJBEi8ibPJVE7IHAvnWkQv/Hhr+UjmcROHse4vpcKuIjo g+a7EJHI7hWSY2RJGOyyzCPlqAPOpmoXw3M= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 33v3vtvjhy-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 29 Sep 2020 21:28:18 -0700 Received: from intmgw002.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 29 Sep 2020 21:28:17 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 8E66A2EC77F1; Tue, 29 Sep 2020 21:28:11 -0700 (PDT) From: Andrii Nakryiko To: CC: , Andrii Nakryiko Subject: [PATCH dwarves 09/11] dwarf_loader: increase the size of lookup hash map Date: Tue, 29 Sep 2020 21:27:40 -0700 Message-ID: <20200930042742.2525310-10-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200930042742.2525310-1-andriin@fb.com> References: <20200930042742.2525310-1-andriin@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-30_01:2020-09-29,2020-09-30 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 lowpriorityscore=0 suspectscore=13 phishscore=0 mlxlogscore=629 clxscore=1015 bulkscore=0 impostorscore=0 adultscore=0 priorityscore=1501 spamscore=0 mlxscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009300032 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org One of the primary use cases for using pahole is BTF deduplication during Linux kernel build. That means that DWARF contains more than 5 million ty= pes is loaded. So using a hash map with a small number of buckets is quite expensive due to hash collisions. This patch bumps the size of the hash m= ap and reduces overhead of this part of the DWARF loading process. This shaves off about 1 second out of about 20 seconds total for Linux BT= F dedup. Signed-off-by: Andrii Nakryiko --- dwarf_loader.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/dwarf_loader.c b/dwarf_loader.c index 63988011978f..05c96bef09e3 100644 --- a/dwarf_loader.c +++ b/dwarf_loader.c @@ -89,7 +89,7 @@ static void dwarf_tag__set_spec(struct dwarf_tag *dtag,= dwarf_off_ref spec) *(dwarf_off_ref *)(dtag + 1) =3D spec; } =20 -#define HASHTAGS__BITS 8 +#define HASHTAGS__BITS 15 #define HASHTAGS__SIZE (1UL << HASHTAGS__BITS) =20 #define obstack_chunk_alloc malloc --=20 2.24.1