From nobody Sun Dec 28 17:29:10 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 999DFC4167B for ; Thu, 7 Dec 2023 01:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1443099AbjLGBTJ (ORCPT ); Wed, 6 Dec 2023 20:19:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1443001AbjLGBSi (ORCPT ); Wed, 6 Dec 2023 20:18:38 -0500 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5FBB91FC3 for ; Wed, 6 Dec 2023 17:18:12 -0800 (PST) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5d9c036769cso1842547b3.2 for ; Wed, 06 Dec 2023 17:18:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1701911891; x=1702516691; darn=vger.kernel.org; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :from:to:cc:subject:date:message-id:reply-to; bh=zhWv5XH2QIvBBYa/R05A/SafwPCuOWvAm4FZ/Ek/rFM=; b=aKrqV2LLaveEeNRG0k5c6Fa2OyEtZKKkinL9NWdjtQ7YQLJxH9WnGGvfKZkZR1nKbV AXU6HylhZeuOeDI6fTq5bNOSs4XQRk84D8coYKv5jbRo3shOuq8VUvTLW16YP9RKvDft OHApy0W9NqJjcthFbVLptVN7dMeRW7sl6vvJ5FYRiMxTb1gIfKYi9nyjWn9sW3eHVBuQ 8mtZjMM081V9zYHnYbsvKNc6mRoENbV2EB4sxsFEQ9USJrGqW9+tSmaG2v9AOXao1m19 IJraUtqlPvbJwmIpP7R4yTUvngdG3eN+LdNKqjANPh0akZklpUFxc1L8kjUGd8lR9IOy ptfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701911891; x=1702516691; h=to:from:subject:references:mime-version:message-id:in-reply-to:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=zhWv5XH2QIvBBYa/R05A/SafwPCuOWvAm4FZ/Ek/rFM=; b=bomDGuEb/MkpCe6NDbzI8n27dDCeMR8viVNDlYvtaOvwSxg2Q3NKTeueKJzgBYybHG cES8yaVnifyydi5IGdm0E/Tu/kITcdAI9NSn54hAg5nP1WKBqDG6kJpW5bOVkyBr8K8q 6A/1cf38m0pMWwnOPD36QEFax1AFPAh+6pNWAradqmRqjw86mvR94H5fHOFQSAw7xD0a BmUL3GsYgRBLn/RhsmVB9a3OiLAvT9fsLq/dA8gMKuSNCs1SX22QEwZ/gM8GA9zcVORu xSu5P+gPE0RFQVF/Egbye8EbmQO5RzBiM2giIzIi84B6QViUQEp05n5/ZK8ZCVIV9mP4 aFTQ== X-Gm-Message-State: AOJu0Yye5ne8/upYslULFMu4wtcfNwHtPK9GVo78GGrlV8epBcTs5clM tnZhgHQ5QrlxvMbESz0I8PFvI+iwwfqG X-Google-Smtp-Source: AGHT+IEWcnmiKEOyMIE+2aNgl2GxOpZtGE8TuU2QEQKPQlYZwpHrrMBjKS7T0LXoVJ/omdKDaVXSGMunSkJj X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:35bf:293e:7696:34e9]) (user=irogers job=sendgmr) by 2002:a81:be14:0:b0:5d1:7706:b886 with SMTP id i20-20020a81be14000000b005d17706b886mr31238ywn.0.1701911891461; Wed, 06 Dec 2023 17:18:11 -0800 (PST) Date: Wed, 6 Dec 2023 17:16:53 -0800 In-Reply-To: <20231207011722.1220634-1-irogers@google.com> Message-Id: <20231207011722.1220634-20-irogers@google.com> Mime-Version: 1.0 References: <20231207011722.1220634-1-irogers@google.com> X-Mailer: git-send-email 2.43.0.rc2.451.g8631bc7472-goog Subject: [PATCH v6 19/47] perf maps: Add maps__load_first From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Nick Terrell , Kan Liang , Andi Kleen , Kajol Jain , Athira Rajeev , Huacai Chen , Masami Hiramatsu , Vincent Whitchurch , "Steinar H. Gunderson" , Liam Howlett , Miguel Ojeda , Colin Ian King , Dmitrii Dolgov <9erthalion6@gmail.com>, Yang Jihong , Ming Wang , James Clark , K Prateek Nayak , Sean Christopherson , Leo Yan , Ravi Bangoria , German Gomez , Changbin Du , Paolo Bonzini , Li Dong , Sandipan Das , liuwenyu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Guilherme Amadio Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Avoid bpf_lock_contention_touching the internal maps data structure by adding a helper function. As access is done directly on the map in maps, hold the read lock to stop it being removed. Signed-off-by: Ian Rogers --- tools/perf/util/bpf_lock_contention.c | 2 +- tools/perf/util/maps.c | 13 +++++++++++++ tools/perf/util/maps.h | 2 ++ 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lo= ck_contention.c index f1716c089c99..31ff19afc20c 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -318,7 +318,7 @@ int lock_contention_read(struct lock_contention *con) } =20 /* make sure it loads the kernel map */ - map__load(maps__first(machine->kmaps)->map); + maps__load_first(machine->kmaps); =20 prev_key =3D NULL; while (!bpf_map_get_next_key(fd, prev_key, &key)) { diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c index 986daa1b0497..024a6c9f72c4 100644 --- a/tools/perf/util/maps.c +++ b/tools/perf/util/maps.c @@ -793,3 +793,16 @@ int maps__merge_in(struct maps *kmaps, struct map *new= _map) } return err; } + +void maps__load_first(struct maps *maps) +{ + struct map_rb_node *first; + + down_read(maps__lock(maps)); + + first =3D maps__first(maps); + if (first) + map__load(first->map); + + up_read(maps__lock(maps)); +} diff --git a/tools/perf/util/maps.h b/tools/perf/util/maps.h index e4a49d6ff5cf..b7ab3ec61b7c 100644 --- a/tools/perf/util/maps.h +++ b/tools/perf/util/maps.h @@ -142,4 +142,6 @@ void __maps__sort_by_name(struct maps *maps); =20 void maps__fixup_end(struct maps *maps); =20 +void maps__load_first(struct maps *maps); + #endif // __PERF_MAPS_H --=20 2.43.0.rc2.451.g8631bc7472-goog