From patchwork Wed Sep 1 13:09:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Patrick Steinhardt X-Patchwork-Id: 12469345 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 811FAC4320E for ; Wed, 1 Sep 2021 13:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6095A6108E for ; Wed, 1 Sep 2021 13:09:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344297AbhIANKn (ORCPT ); Wed, 1 Sep 2021 09:10:43 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:58581 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244182AbhIANKl (ORCPT ); Wed, 1 Sep 2021 09:10:41 -0400 Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailout.nyi.internal (Postfix) with ESMTP id B43AB5C01ED; Wed, 1 Sep 2021 09:09:44 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Wed, 01 Sep 2021 09:09:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pks.im; h=date :from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm1; bh=S+iORiJSq+O9mauh7nhC1KPkPx4 ePloJrZEVJJQhN9w=; b=bTriAwbG70Hk3cQJAe2nIh0OShDtBli2k7ngfOKlHPV UYpVmEJeDpIpuUrWO6qyjoSPMVQo4ZnyESiaBfgLnB1K3H3NLCkNsZTkHkoNUrns xvjT2h82k8K7EZrgH1QILJVaeJpFstGYMg8VMvbXkQL68Exuvg0smHwbnZmBMb5y ivrXFNtnc1mCJdoDSE9bTfNBCp3YIk05PHo5AKDdbj5q4kjvf2lZwIhDCm6OWIUz OYD3p1MYYFncIaTRZ8QthdSYtAjuWH5Pq5BGn3ICt86C8120Tbso2CCt49j1O+eS OmKGcnZ10a+reoyzjIwXe/mTDkdTxaov2LJV0bjuDyQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=S+iORi JSq+O9mauh7nhC1KPkPx4ePloJrZEVJJQhN9w=; b=HeJ0OozaI8bJcauxiESm4N hhYigzNKwhzvbA/5EyzzWtlupbgBaIH2j4nAprUZpvtPyZ4RNxa0rvU+VB5ypNSf qGBMUaXuMs4wkJfACDG4ylDV9N0J3z2vkdA4vCgFEJhUlt4Wibc45v6ptEYrbpQt +O8DaPmHuskyCV7ZdDMhU6yS9K500Oy51b0rujYVosGET1jLZ1qNw16Datp+Duee xwhBuaZ4vv4c5ajUiVd6rdKNquDV4dSIg5nPQo+BsNeA3f2J2mNKpR6kaSLWaNLA 0XKi8uNTxtErU3JZDPL9YUvl4EapdO2W96TCLR64MJhObyc70oIjRHBuap8lBydg == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvtddruddvfedgiedtucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehgtderredttdejnecuhfhrohhmpefrrghtrhhi tghkucfuthgvihhnhhgrrhguthcuoehpshesphhkshdrihhmqeenucggtffrrghtthgvrh hnpeehgfejueevjeetudehgffffeffvdejfeejiedvkeffgfekuefgheevteeufeelkeen ucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehpshesph hkshdrihhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 1 Sep 2021 09:09:43 -0400 (EDT) Received: from localhost (ncase [10.192.0.11]) by vm-mail.pks.im (OpenSMTPD) with ESMTPSA id baa47f15 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Wed, 1 Sep 2021 13:09:42 +0000 (UTC) Date: Wed, 1 Sep 2021 15:09:41 +0200 From: Patrick Steinhardt To: git@vger.kernel.org Cc: Jeff King , =?iso-8859-1?q?=C6var_Arnfj=F6r=F0?= Bjarmason , Junio C Hamano , Derrick Stolee , =?iso-8859-1?q?Ren=E9?= Scharfe Subject: [PATCH v3 1/7] fetch: speed up lookup of want refs via commit-graph Message-ID: <8214f04971c4ea628f23d2e9ea143d87570c29d2.1630501732.git.ps@pks.im> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org When updating our local refs based on the refs fetched from the remote, we need to iterate through all requested refs and load their respective commits such that we can determine whether they need to be appended to FETCH_HEAD or not. In cases where we're fetching from a remote with exceedingly many refs, resolving these refs can be quite expensive given that we repeatedly need to unpack object headers for each of the referenced objects. Speed this up by opportunistically trying to resolve object IDs via the commit graph. We only do so for any refs which are not in "refs/tags": more likely than not, these are going to be a commit anyway, and this lets us avoid having to unpack object headers completely in case the object is a commit that is part of the commit-graph. This significantly speeds up mirror-fetches in a real-world repository with 2.3M refs: Benchmark #1: HEAD~: git-fetch Time (mean ± σ): 56.482 s ± 0.384 s [User: 53.340 s, System: 5.365 s] Range (min … max): 56.050 s … 57.045 s 5 runs Benchmark #2: HEAD: git-fetch Time (mean ± σ): 33.727 s ± 0.170 s [User: 30.252 s, System: 5.194 s] Range (min … max): 33.452 s … 33.871 s 5 runs Summary 'HEAD: git-fetch' ran 1.67 ± 0.01 times faster than 'HEAD~: git-fetch' Signed-off-by: Patrick Steinhardt --- builtin/fetch.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/builtin/fetch.c b/builtin/fetch.c index 25740c13df..bd7c0da232 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -1074,7 +1074,6 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, int connectivity_checked, struct ref *ref_map) { struct fetch_head fetch_head; - struct commit *commit; int url_len, i, rc = 0; struct strbuf note = STRBUF_INIT, err = STRBUF_INIT; struct ref_transaction *transaction = NULL; @@ -1122,6 +1121,7 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, want_status <= FETCH_HEAD_IGNORE; want_status++) { for (rm = ref_map; rm; rm = rm->next) { + struct commit *commit = NULL; struct ref *ref = NULL; if (rm->status == REF_STATUS_REJECT_SHALLOW) { @@ -1131,11 +1131,23 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, continue; } - commit = lookup_commit_reference_gently(the_repository, - &rm->old_oid, - 1); - if (!commit) - rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE; + /* + * References in "refs/tags/" are often going to point + * to annotated tags, which are not part of the + * commit-graph. We thus only try to look up refs in + * the graph which are not in that namespace to not + * regress performance in repositories with many + * annotated tags. + */ + if (!starts_with(rm->name, "refs/tags/")) + commit = lookup_commit_in_graph(the_repository, &rm->old_oid); + if (!commit) { + commit = lookup_commit_reference_gently(the_repository, + &rm->old_oid, + 1); + if (!commit) + rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE; + } if (rm->fetch_head_status != want_status) continue;