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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A27EC4332F for ; Thu, 2 Nov 2023 18:00:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345562AbjKBSAU (ORCPT ); Thu, 2 Nov 2023 14:00:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377259AbjKBR72 (ORCPT ); Thu, 2 Nov 2023 13:59:28 -0400 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 4940E10F3 for ; Thu, 2 Nov 2023 10:58:52 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5b3715f3b41so16864837b3.2 for ; Thu, 02 Nov 2023 10:58:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698947931; x=1699552731; 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=UjGLpULVRUxYABNs8KK8hib6JmANLHcuQm1tIO1QTLc=; b=ER89x3QBSjW75W4RiQdRTVKtAxJHVgvda9Wayj8xyj7MRXcx4tLWCOeoLY4QQ/S6oH F/+U79jPBKgdjYjmmTi4JZMnc04mDRMvXrIWEo7LW/pfBNqdetmIfEK0zhHEWI8drs9D RHi6LGkMDc6JqV0h1MAgeAfscLsnwmQaQ+fEj+/6dIDa2MQEDrIQ//6/mFNQ8Y8jxdoV wzVde1G5nZ8o32XkKO41x6CZe/CDlVukhGIsY5m3fSctSrh1xEsSR9YO2l0smLMPNimI ZqlHuLtC37bxumhr2GPvKs9YogLsOTGYArBXhmBEkc6500EJSLVv/BGIq3qFFiHwnNCE /3ew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698947931; x=1699552731; 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=UjGLpULVRUxYABNs8KK8hib6JmANLHcuQm1tIO1QTLc=; b=G7S8AztorjzL8ZHXiNh/qyO2XcT/6mQEUTUNK+Mqlo0Uvt46uAzBR7Pd5Cpf3oDA+c Fh8M6E7x5T2ChhYgLI4/6eYDkvceR305DTEvIe3ezj6bAyc3XTbJf5M2JcIdS9uNlJLi iY9G6E5Omb+JXakziGA30ObpK/4v/R0hYFAVoqI65Ow8D3bcAAzxCH62Gs8DNSXpQZku Yd/Gm55DwlG+f9XqSfR2qI0cHEkHUyd8tW9R5Wi1GQT1Ohjpuv//Fn2dkVzsa4JQ5AA9 Lt047gTRbMAlKES41lLdG4ZWIjZAlOZsmutSw+JnjxOJpfHL51uJ6zaE1i+AZeheGQOB 0Lrw== X-Gm-Message-State: AOJu0Yx8vgIG+DzNRs+VSpKWsydQAmG9Eeu/bakDdzzc1K/PUuG+bEuE IaF8YviUiHwVOQ2sCm8gAHrmTYoG5pxy X-Google-Smtp-Source: AGHT+IEaqoxnS8RYuF+B0Tq+gELTQ54gaKcVVdKaiSS1qLvvW9EX9LtcaPvY9lTdk6v6MN54IVKOKzEE90HZ X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:bb34:df9c:836c:afca]) (user=irogers job=sendgmr) by 2002:a81:5249:0:b0:5a1:d329:829c with SMTP id g70-20020a815249000000b005a1d329829cmr9123ywb.0.1698947931428; Thu, 02 Nov 2023 10:58:51 -0700 (PDT) Date: Thu, 2 Nov 2023 10:57:06 -0700 In-Reply-To: <20231102175735.2272696-1-irogers@google.com> Message-Id: <20231102175735.2272696-25-irogers@google.com> Mime-Version: 1.0 References: <20231102175735.2272696-1-irogers@google.com> X-Mailer: git-send-email 2.42.0.869.gea05f2083d-goog Subject: [PATCH v4 24/53] 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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_lock_contention.c index e105245eb905..d9720a910330 100644 --- a/tools/perf/util/bpf_lock_contention.c +++ b/tools/perf/util/bpf_lock_contention.c @@ -317,7 +317,7 @@ int lock_contention_read(struct lock_contention *con) } /* make sure it loads the kernel map */ - map__load(maps__first(machine->kmaps)->map); + maps__load_first(machine->kmaps); prev_key = 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 85bea2a6dca9..9a84d26328a7 100644 --- a/tools/perf/util/maps.c +++ b/tools/perf/util/maps.c @@ -792,3 +792,16 @@ 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 = 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); void maps__fixup_end(struct maps *maps); +void maps__load_first(struct maps *maps); + #endif // __PERF_MAPS_H -- 2.42.0.869.gea05f2083d-goog