linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Byungchul Park <byungchul.park@lge.com>
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>, <iamjoonsoo.kim@lge.com>,
	<akpm@linux-foundation.org>, <willy@infradead.org>,
	<npiggin@gmail.com>, <kernel-team@lge.com>
Subject: [PATCH v6 03/15] lockdep: Change the meaning of check_prev_add()'s return value
Date: Tue, 14 Mar 2017 17:18:50 +0900	[thread overview]
Message-ID: <1489479542-27030-4-git-send-email-byungchul.park@lge.com> (raw)
In-Reply-To: <1489479542-27030-1-git-send-email-byungchul.park@lge.com>

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 <byungchul.park@lge.com>
---
 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 eb39474..4709110 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1854,7 +1854,7 @@ static inline void inc_chains(void)
 		if (entry->class == hlock_class(next)) {
 			if (distance == 1)
 				entry->distance = 1;
-			return 2;
+			return 1;
 		}
 	}
 
@@ -1894,9 +1894,10 @@ 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

  parent reply	other threads:[~2017-03-14  8:22 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-14  8:18 [PATCH v6 00/15] lockdep: Implement crossrelease feature Byungchul Park
2017-03-14  8:18 ` [PATCH v6 01/15] lockdep: Refactor lookup_chain_cache() Byungchul Park
2017-03-14  8:18 ` [PATCH v6 02/15] lockdep: Add a function building a chain between two classes Byungchul Park
2017-03-14  8:18 ` Byungchul Park [this message]
2017-03-14  8:18 ` [PATCH v6 04/15] lockdep: Make check_prev_add() able to handle external stack_trace Byungchul Park
2017-03-14  8:18 ` [PATCH v6 05/15] lockdep: Implement crossrelease feature Byungchul Park
2017-04-19 14:25   ` Peter Zijlstra
2017-04-24  5:11     ` Byungchul Park
2017-04-24 10:17       ` Peter Zijlstra
2017-04-25  5:40         ` Byungchul Park
2017-05-16 14:18           ` Peter Zijlstra
2017-05-18  6:22             ` Byungchul Park
2017-04-19 15:08   ` Peter Zijlstra
2017-04-24  4:36     ` Byungchul Park
2017-04-19 17:19   ` Peter Zijlstra
2017-04-24  3:04     ` Byungchul Park
2017-04-24  9:30       ` Peter Zijlstra
2017-04-25  6:59         ` Byungchul Park
2017-04-19 17:20   ` Peter Zijlstra
2017-04-24  3:13     ` Byungchul Park
2017-05-19  8:07   ` Byungchul Park
2017-05-19 10:30     ` Peter Zijlstra
2017-05-19 10:56       ` Byungchul Park
2017-03-14  8:18 ` [PATCH v6 06/15] lockdep: Handle non(or multi)-acquisition of a crosslock Byungchul Park
2017-03-14  8:18 ` [PATCH v6 07/15] lockdep: Avoid adding redundant direct links of crosslocks Byungchul Park
2017-03-14  8:18 ` [PATCH v6 08/15] lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS Byungchul Park
2017-03-14  8:18 ` [PATCH v6 09/15] lockdep: Make print_circular_bug() aware of crossrelease Byungchul Park
2017-03-14  8:18 ` [PATCH v6 10/15] lockdep: Apply crossrelease to completions Byungchul Park
2017-03-14  8:18 ` [PATCH v6 11/15] pagemap.h: Remove trailing white space Byungchul Park
2017-03-14  8:18 ` [PATCH v6 12/15] lockdep: Apply crossrelease to PG_locked locks Byungchul Park
2017-03-14  8:19 ` [PATCH v6 13/15] lockdep: Apply lock_acquire(release) on __Set(__Clear)PageLocked Byungchul Park
2017-03-14  8:19 ` [PATCH v6 14/15] lockdep: Move data of CONFIG_LOCKDEP_PAGELOCK from page to page_ext Byungchul Park
2017-03-14  8:19 ` [PATCH v6 15/15] lockdep: Crossrelease feature documentation Byungchul Park

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1489479542-27030-4-git-send-email-byungchul.park@lge.com \
    --to=byungchul.park@lge.com \
    --cc=akpm@linux-foundation.org \
    --cc=boqun.feng@gmail.com \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=kernel-team@lge.com \
    --cc=kirill@shutemov.name \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mingo@kernel.org \
    --cc=npiggin@gmail.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=walken@google.com \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).