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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 92CA4C4321A for ; Fri, 28 Jun 2019 09:16:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 60218208CB for ; Fri, 28 Jun 2019 09:16:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="a+0xqXz4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726871AbfF1JQQ (ORCPT ); Fri, 28 Jun 2019 05:16:16 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:42545 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726823AbfF1JQP (ORCPT ); Fri, 28 Jun 2019 05:16:15 -0400 Received: by mail-pl1-f196.google.com with SMTP id ay6so2885341plb.9 for ; Fri, 28 Jun 2019 02:16:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=I9dPsEtJCEiuhZNIYsC+o8qAD4cE4xsOv38Yk3OtHVU=; b=a+0xqXz406H/gWw9iI88Ua4QzScP+2/k2GPlX5ljJG3Yv8beQlYGPZQqhs7gXfI1C+ LF/kV9Se5mIaB43eSPYbO2hhqbdtOk1KriLDs1wKOwEUSKiT4D4Tac2ZSqUNVyA37OkO bg8+ntq5nfKPWEPnXYsC/zyjW3VuCsSbOoPEO47oOLMDdRVTszxE1tZhxuYcWgdvM9AI DgWzCuDyP8xCjf3BF1jaNDZDOhVrVd3Iq+ODLwm9mvTMXDeulx/zr6h+0omrlmi+riwb +UWqh/++OIIJwq/8FRVP5N4blou6xL1woRSvqcCMI8HNX+JPC2lLQ9GEe5mIm8scASFc fnAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=I9dPsEtJCEiuhZNIYsC+o8qAD4cE4xsOv38Yk3OtHVU=; b=LaU4PR6A8J4XKIvLiS8FgpLdb043MSyyifZ4Zs4YdxfirvXA5BzrtF4v/3DxW6Tz07 YpCD/+OlfpPOHSa98IWgi0pd9bB+7T67kM8w8H+VB2az57Z+4HNpfVpXCQt0CRqSN399 tUJwvr4i1+li0NcwfiBlQDbi9Xg6giWhZ5qIXNk+7oZrwdGYix9MAme658i0IAM+Wmzn AowAcbTC7XtMniUmNc1LsJJ6BsruNYV9SPHFztRw8dMj94voBSFwndpDndJhIzFn3UKU gZsPtsl5URHgdAV5PN2y41dKorXSefwxNWywe4C/yavVlL6pCRsikljVcE+1i5Nnhd1H ZCPg== X-Gm-Message-State: APjAAAX7UO4nKwzBAnevqu5BcVkQ3D5nVZaeaFGZs9VfbkRjAKvpqkeh g94c9fW370JxwmMuGG/KMEc= X-Google-Smtp-Source: APXvYqwGs4QmXLyIvd3ejZvYmwbgViyP+2geKsL+QgWMy6kgum64Rh5GaWyola68ccEN88uMve+H3A== X-Received: by 2002:a17:902:9a84:: with SMTP id w4mr10086499plp.160.1561713374992; Fri, 28 Jun 2019 02:16:14 -0700 (PDT) Received: from localhost.localdomain ([203.100.54.194]) by smtp.gmail.com with ESMTPSA id x65sm1754521pfd.139.2019.06.28.02.16.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 28 Jun 2019 02:16:14 -0700 (PDT) From: Yuyang Du To: peterz@infradead.org, will.deacon@arm.com, mingo@kernel.org Cc: bvanassche@acm.org, ming.lei@redhat.com, frederic@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, longman@redhat.com, paulmck@linux.vnet.ibm.com, boqun.feng@gmail.com, Yuyang Du Subject: [PATCH v3 07/30] locking/lockdep: Remove indirect dependency redundancy check Date: Fri, 28 Jun 2019 17:15:05 +0800 Message-Id: <20190628091528.17059-8-duyuyang@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) In-Reply-To: <20190628091528.17059-1-duyuyang@gmail.com> References: <20190628091528.17059-1-duyuyang@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Indirect dependency redundancy check was added for cross-release, which has been reverted. Then suggested by Peter, only when setting CONFIG_LOCKDEP_SMALL it takes effect. With (recursive) read-write lock types considered in dependency graph, indirect dependency redundancy check would be very complicated if not impossible to be correctly done. Lets remove it for good. Signed-off-by: Yuyang Du --- kernel/locking/lockdep.c | 41 -------------------------------------- kernel/locking/lockdep_internals.h | 1 - kernel/locking/lockdep_proc.c | 2 -- 3 files changed, 44 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index f171c6e..c61fdef 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1744,38 +1744,6 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class) return ret; } -#ifdef CONFIG_LOCKDEP_SMALL -/* - * Check that the dependency graph starting at can lead to - * or not. If it can, -> dependency is already - * in the graph. - * - * Print an error and return 2 if it does or 1 if it does not. - */ -static noinline int -check_redundant(struct held_lock *src, struct held_lock *target) -{ - int ret; - struct lock_list *uninitialized_var(target_entry); - struct lock_list src_entry = { - .class = hlock_class(src), - .parent = NULL, - }; - - debug_atomic_inc(nr_redundant_checks); - - ret = check_path(hlock_class(target), &src_entry, &target_entry); - - if (!ret) { - debug_atomic_inc(nr_redundant); - ret = 2; - } else if (ret < 0) - ret = 0; - - return ret; -} -#endif - #ifdef CONFIG_TRACE_IRQFLAGS static inline int usage_accumulate(struct lock_list *entry, void *mask) @@ -2437,15 +2405,6 @@ static inline void inc_chains(void) } } -#ifdef CONFIG_LOCKDEP_SMALL - /* - * Is the -> link redundant? - */ - ret = check_redundant(prev, next); - if (ret != 1) - return ret; -#endif - if (!trace->nr_entries && !save_trace(trace)) return 0; diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index cc83568..e9a8ed6 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -170,7 +170,6 @@ struct lockdep_stats { unsigned long redundant_softirqs_on; unsigned long redundant_softirqs_off; int nr_unused_locks; - unsigned int nr_redundant_checks; unsigned int nr_redundant; unsigned int nr_cyclic_checks; unsigned int nr_find_usage_forwards_checks; diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 9c49ec6..58ed889 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -178,8 +178,6 @@ static void lockdep_stats_debug_show(struct seq_file *m) debug_atomic_read(chain_lookup_hits)); seq_printf(m, " cyclic checks: %11llu\n", debug_atomic_read(nr_cyclic_checks)); - seq_printf(m, " redundant checks: %11llu\n", - debug_atomic_read(nr_redundant_checks)); seq_printf(m, " redundant links: %11llu\n", debug_atomic_read(nr_redundant)); seq_printf(m, " find-mask forwards checks: %11llu\n", -- 1.8.3.1