From nobody Thu Jan 1 08:57:39 2026 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 9EDE2C25B47 for ; Tue, 24 Oct 2023 22:24:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344439AbjJXWYW (ORCPT ); Tue, 24 Oct 2023 18:24:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234958AbjJXWYS (ORCPT ); Tue, 24 Oct 2023 18:24:18 -0400 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 2FD5B10D1 for ; Tue, 24 Oct 2023 15:24:16 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-d9cafa90160so5745255276.2 for ; Tue, 24 Oct 2023 15:24:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698186255; x=1698791055; 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=NM9dcQFM3UJZ90iyVMmsCAaNS1wz3u9iN52BCuG9Qew=; b=meDc3XHpY9ExaB280nqOJ6K12OSUwce6tf+IECrl3phpC11mlm2lK0RtXg1hlcetqQ IARFzopmnj2l0M1LYYdylBWVYy8/qq2za77E8GuduEiFUQJyM9cjX9GO45Fiil3YMs6Y GY3R2xmNPk5JnsdAhz+XU2mGcSN++OBrYzAvjbRZU5i9w7OSu5mV/7UmwQRYvderROeH qFtLHtmi3fAE89TaP/eI9TrrMZosgnEr2XPChozMnTtw2Q2rXVkY0eIs5kE5k/VjROEs M4j+fFEFoz23hcJILF8zpJj/P9hNWAXbMOqtnsHCx7dDkufNWU8GmNTqVk1gMtn7S+Q1 LfIA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698186255; x=1698791055; 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=NM9dcQFM3UJZ90iyVMmsCAaNS1wz3u9iN52BCuG9Qew=; b=nqnVu+0weadMj83l6jmG+VzU0F3NLIF+un41zNGbA4a78a/6pnh1c5DBA0D7lIJpnY fVJswvGlfXaQUPMwwmc8wvXC1ObSffGttzXXhRfoltekHb0k3HsXAEjbQjyS88T9+/Zr GcLNUVuvIb9MlSiT3oAsA+6sgBCyyoyWfZiubjmwA+E4PazPXYMhYm6S7SBf8Wel+PjG rZZWYhqxkGUIO0Q+m0JmoFR3DOCsRW4pApBUFHnJR8smhcVSf7a6+0gqjGvw9Egb2JMP QVu4oqRqT0uVHvEtnKoWDXejNdvUplPEQg/4NS9boJbKSs9CfFjlIvPoa+yLcdpbPh74 A6YA== X-Gm-Message-State: AOJu0Yw+m51ZQmHMjVI5+zkXw93cKuzH1j1ydOYjiQh7Kef27QpD5p/1 DteBeSVoEfds8KM8iuYvfS5rewQZ9qtw X-Google-Smtp-Source: AGHT+IF7nlRfsAq1YqcW3CsH70jSGEhchSRGYDNQ7SmWyO76Nk3DNu3kvo4mRn/43YxUo7ddKr0wFqtUs8/z X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:93d2:18cc:4d63:45ba]) (user=irogers job=sendgmr) by 2002:a25:d107:0:b0:d9a:50d2:a8ba with SMTP id i7-20020a25d107000000b00d9a50d2a8bamr250692ybg.2.1698186255187; Tue, 24 Oct 2023 15:24:15 -0700 (PDT) Date: Tue, 24 Oct 2023 15:23:04 -0700 In-Reply-To: <20231024222353.3024098-1-irogers@google.com> Message-Id: <20231024222353.3024098-2-irogers@google.com> Mime-Version: 1.0 References: <20231024222353.3024098-1-irogers@google.com> X-Mailer: git-send-email 2.42.0.758.gaed0368e0e-goog Subject: [PATCH v3 01/50] perf rwsem: Add debug mode that uses a mutex 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 , Leo Yan , Song Liu , Sandipan Das , James Clark , Anshuman Khandual , Miguel Ojeda , Liam Howlett , Yang Jihong , Athira Rajeev , Kajol Jain , K Prateek Nayak , Sean Christopherson , Yanteng Si , Ravi Bangoria , German Gomez , Changbin Du , Paolo Bonzini , Masami Hiramatsu , liuwenyu , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Mutex error check will capture trying to take the lock recursively and other problems that rwlock won't. At the expense of concurrency, adda debug mode that uses a mutex in place of a rwsem. Signed-off-by: Ian Rogers --- tools/perf/util/rwsem.c | 34 ++++++++++++++++++++++++++++++++++ tools/perf/util/rwsem.h | 11 +++++++++++ 2 files changed, 45 insertions(+) diff --git a/tools/perf/util/rwsem.c b/tools/perf/util/rwsem.c index f3d29d8ddc99..5109167f27f7 100644 --- a/tools/perf/util/rwsem.c +++ b/tools/perf/util/rwsem.c @@ -2,32 +2,66 @@ #include "util.h" #include "rwsem.h" =20 +#if RWS_ERRORCHECK +#include "mutex.h" +#endif + int init_rwsem(struct rw_semaphore *sem) { +#if RWS_ERRORCHECK + mutex_init(&sem->mtx); + return 0; +#else return pthread_rwlock_init(&sem->lock, NULL); +#endif } =20 int exit_rwsem(struct rw_semaphore *sem) { +#if RWS_ERRORCHECK + mutex_destroy(&sem->mtx); + return 0; +#else return pthread_rwlock_destroy(&sem->lock); +#endif } =20 int down_read(struct rw_semaphore *sem) { +#if RWS_ERRORCHECK + mutex_lock(&sem->mtx); + return 0; +#else return perf_singlethreaded ? 0 : pthread_rwlock_rdlock(&sem->lock); +#endif } =20 int up_read(struct rw_semaphore *sem) { +#if RWS_ERRORCHECK + mutex_unlock(&sem->mtx); + return 0; +#else return perf_singlethreaded ? 0 : pthread_rwlock_unlock(&sem->lock); +#endif } =20 int down_write(struct rw_semaphore *sem) { +#if RWS_ERRORCHECK + mutex_lock(&sem->mtx); + return 0; +#else return perf_singlethreaded ? 0 : pthread_rwlock_wrlock(&sem->lock); +#endif } =20 int up_write(struct rw_semaphore *sem) { +#if RWS_ERRORCHECK + mutex_unlock(&sem->mtx); + return 0; +#else return perf_singlethreaded ? 0 : pthread_rwlock_unlock(&sem->lock); +#endif } diff --git a/tools/perf/util/rwsem.h b/tools/perf/util/rwsem.h index 94565ad4d494..ef5cbc31d967 100644 --- a/tools/perf/util/rwsem.h +++ b/tools/perf/util/rwsem.h @@ -2,9 +2,20 @@ #define _PERF_RWSEM_H =20 #include +#include "mutex.h" + +/* + * Mutexes have additional error checking. Enable to use a mutex rather th= an a + * rwlock for debugging. + */ +#define RWS_ERRORCHECK 0 =20 struct rw_semaphore { +#if RWS_ERRORCHECK + struct mutex mtx; +#else pthread_rwlock_t lock; +#endif }; =20 int init_rwsem(struct rw_semaphore *sem); --=20 2.42.0.758.gaed0368e0e-goog