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(unknown [120.245.2.120]) by pv50p00im-zteg10011401.me.com (Postfix) with ESMTPSA id 58A839005F1; Wed, 16 Jun 2021 14:42:27 +0000 (UTC) From: Xiongwei Song To: peterz@infradead.org, mingo@redhat.com, will@kernel.org, longman@redhat.com, boqun.feng@gmail.com Cc: linux-kernel@vger.kernel.org, Xiongwei Song Subject: [PATCH] locking/lockdep: unlikely bfs error check Date: Wed, 16 Jun 2021 22:42:09 +0800 Message-Id: <20210616144210.278662-1-sxwjean@me.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-06-16_07:2021-06-15,2021-06-16 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-2009150000 definitions=main-2106160085 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiongwei Song The error from graph walk is small probability event, so unlikely bfs_error can improve performance a little bit. Signed-off-by: Xiongwei Song --- kernel/locking/lockdep.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 074fd6418c20..af8c9203cd3e 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -2646,7 +2646,7 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, bfs_init_rootb(&this, prev); ret = __bfs_backwards(&this, &usage_mask, usage_accumulate, usage_skip, NULL); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -2664,7 +2664,7 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, bfs_init_root(&that, next); ret = find_usage_forwards(&that, forward_mask, &target_entry1); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -2679,7 +2679,7 @@ static int check_irq_usage(struct task_struct *curr, struct held_lock *prev, backward_mask = original_mask(target_entry1->class->usage_mask); ret = find_usage_backwards(&this, backward_mask, &target_entry); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -2998,7 +2998,7 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, * Is the -> link redundant? */ ret = check_redundant(prev, next); - if (bfs_error(ret)) + if (unlikely(bfs_error(ret))) return 0; else if (ret == BFS_RMATCH) return 2; @@ -3911,7 +3911,7 @@ check_usage_forwards(struct task_struct *curr, struct held_lock *this, bfs_init_root(&root, this); ret = find_usage_forwards(&root, usage_mask, &target_entry); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } @@ -3946,7 +3946,7 @@ check_usage_backwards(struct task_struct *curr, struct held_lock *this, bfs_init_rootb(&root, this); ret = find_usage_backwards(&root, usage_mask, &target_entry); - if (bfs_error(ret)) { + if (unlikely(bfs_error(ret))) { print_bfs_bug(ret); return 0; } -- 2.30.2