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From: tip-bot for Waiman Long <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
	paulmck@linux.vnet.ibm.com, hpa@zytor.com, mingo@kernel.org,
	longman@redhat.com, akpm@linux-foundation.org,
	torvalds@linux-foundation.org, will.deacon@arm.com,
	peterz@infradead.org
Subject: [tip:locking/core] locking/qspinlock: Remove unnecessary BUG_ON() call
Date: Wed, 27 Feb 2019 23:02:01 -0800	[thread overview]
Message-ID: <tip-733000c7ffd9d9c8c4fdfd82f0d41956c8cf0537@git.kernel.org> (raw)
In-Reply-To: <1551057253-3231-1-git-send-email-longman@redhat.com>

Commit-ID:  733000c7ffd9d9c8c4fdfd82f0d41956c8cf0537
Gitweb:     https://git.kernel.org/tip/733000c7ffd9d9c8c4fdfd82f0d41956c8cf0537
Author:     Waiman Long <longman@redhat.com>
AuthorDate: Sun, 24 Feb 2019 20:14:13 -0500
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 28 Feb 2019 07:55:38 +0100

locking/qspinlock: Remove unnecessary BUG_ON() call

With the > 4 nesting levels case handled by the commit:

  d682b596d993 ("locking/qspinlock: Handle > 4 slowpath nesting levels")

the BUG_ON() call in encode_tail() will never actually be triggered.

Remove it.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1551057253-3231-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/locking/qspinlock.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
index 21ee51b47961..5e9247dc2515 100644
--- a/kernel/locking/qspinlock.c
+++ b/kernel/locking/qspinlock.c
@@ -124,9 +124,6 @@ static inline __pure u32 encode_tail(int cpu, int idx)
 {
 	u32 tail;
 
-#ifdef CONFIG_DEBUG_SPINLOCK
-	BUG_ON(idx > 3);
-#endif
 	tail  = (cpu + 1) << _Q_TAIL_CPU_OFFSET;
 	tail |= idx << _Q_TAIL_IDX_OFFSET; /* assume < 4 */
 

      parent reply	other threads:[~2019-02-28  7:02 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-25  1:14 [PATCH-tip] " Waiman Long
2019-02-25 12:12 ` Will Deacon
2019-02-28  7:02 ` tip-bot for Waiman Long [this message]

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