From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752454AbdHGHQM (ORCPT ); Mon, 7 Aug 2017 03:16:12 -0400 Received: from LGEAMRELO12.lge.com ([156.147.23.52]:41714 "EHLO lgeamrelo12.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752082AbdHGHON (ORCPT ); Mon, 7 Aug 2017 03:14:13 -0400 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: peterz@infradead.org, mingo@kernel.org Cc: tglx@linutronix.de, walken@google.com, boqun.feng@gmail.com, kirill@shutemov.name, linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, willy@infradead.org, npiggin@gmail.com, kernel-team@lge.com Subject: [PATCH v8 03/14] lockdep: Change the meaning of check_prev_add()'s return value Date: Mon, 7 Aug 2017 16:12:50 +0900 Message-Id: <1502089981-21272-4-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1502089981-21272-1-git-send-email-byungchul.park@lge.com> References: <1502089981-21272-1-git-send-email-byungchul.park@lge.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Firstly, return 1 instead of 2 when 'prev -> next' dependency already exists. Since the value 2 is not referenced anywhere, just return 1 indicating success in this case. Secondly, return 2 instead of 1 when successfully added a lock_list entry with saving stack_trace. With that, a caller can decide whether to avoid redundant save_trace() on the caller site. Signed-off-by: Byungchul Park --- kernel/locking/lockdep.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 9d16723..b23e930 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1870,7 +1870,7 @@ static inline void inc_chains(void) if (entry->class == hlock_class(next)) { if (distance == 1) entry->distance = 1; - return 2; + return 1; } } @@ -1910,9 +1910,10 @@ static inline void inc_chains(void) print_lock_name(hlock_class(next)); printk(KERN_CONT "\n"); dump_stack(); - return graph_lock(); + if (!graph_lock()) + return 0; } - return 1; + return 2; } /* -- 1.9.1