From: Ingo Molnar <mingo@kernel.org>
To: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 5/5] locking/lockdep: Call lock_release after releasing the lock
Date: Tue, 2 Oct 2018 11:08:48 +0200 [thread overview]
Message-ID: <20181002090848.GD116695@gmail.com> (raw)
In-Reply-To: <1538157201-29173-6-git-send-email-longman@redhat.com>
* Waiman Long <longman@redhat.com> wrote:
> Subject: locking/lockdep: Call lock_release after releasing the lock
s/lock_release
/lock_release()
> Currently, lock_acquire() is called before acquiring the lock and
> lock_release() is called before the releasing the lock. As a result,
> the execution time of lock_release() is added to the lock hold time
> reducing locking throughput, especially for spinlocks and rwlocks which
> tend to have a much shorter lock hold time.
>
> As lock_release() is not going to update any shared data that needs
> protection from the lock, we don't actually need to call it before
> releasing the lock. So the lock_release() calls are now postponed to
> after releasing the lock for spinlocks and rwlocks.
Nice optimization!
Thanks,
Ingo
next prev parent reply other threads:[~2018-10-02 9:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-28 17:53 [PATCH 0/5] locking/lockdep: Improve lockdep performance Waiman Long
2018-09-28 17:53 ` [PATCH 1/5] locking/lockdep: Remove add_chain_cache_classes() Waiman Long
2018-09-28 17:53 ` [PATCH 2/5] locking/lockdep: Eliminate redundant irqs check in __lock_acquire() Waiman Long
2018-10-02 9:06 ` Ingo Molnar
2018-09-28 17:53 ` [PATCH 3/5] locking/lockdep: Add a faster path in __lock_release() Waiman Long
2018-10-02 9:03 ` Ingo Molnar
2018-09-28 17:53 ` [PATCH 4/5] locking/lockdep: Make class->ops a percpu counter Waiman Long
2018-09-28 20:25 ` kbuild test robot
2018-09-28 20:31 ` Waiman Long
2018-09-28 20:42 ` kbuild test robot
2018-10-02 9:39 ` Peter Zijlstra
2018-10-02 9:55 ` Ingo Molnar
2018-10-02 14:10 ` Waiman Long
2018-10-02 14:28 ` Peter Zijlstra
2018-10-02 18:53 ` Ingo Molnar
2018-09-28 17:53 ` [PATCH 5/5] locking/lockdep: Call lock_release after releasing the lock Waiman Long
2018-10-02 9:08 ` Ingo Molnar [this message]
2018-10-02 9:06 ` [PATCH 0/5] locking/lockdep: Improve lockdep performance Ingo Molnar
2018-10-02 13:57 ` Waiman Long
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