From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jonathan Corbet <corbet@lwn.net>,
Josh Triplett <josh@joshtriplett.org>,
Lai Jiangshan <jiangshanlai@gmail.com>,
linux-doc@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
"Rafael J. Wysocki" <rafael@kernel.org>,
rcu@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
Tejun Heo <tj@kernel.org>
Subject: Re: [PATCH v3 -rcu] workqueue: Convert for_each_wq to use built-in list check
Date: Fri, 16 Aug 2019 09:45:21 -0700 [thread overview]
Message-ID: <20190816164521.GR28441@linux.ibm.com> (raw)
In-Reply-To: <20190815141842.GB20599@google.com>
On Thu, Aug 15, 2019 at 10:18:42AM -0400, Joel Fernandes (Google) wrote:
> list_for_each_entry_rcu now has support to check for RCU reader sections
> as well as lock. Just use the support in it, instead of explicitly
> checking in the caller.
>
> Acked-by: Tejun Heo <tj@kernel.org>
> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Pulled into -rcu for testing and further review, thank you!
Thanx, Paul
> ---
> v1->v3: Changed lock_is_held() to lockdep_is_held()
>
> kernel/workqueue.c | 10 ++--------
> 1 file changed, 2 insertions(+), 8 deletions(-)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 601d61150b65..e882477ebf6e 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -364,11 +364,6 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
> !lockdep_is_held(&wq_pool_mutex), \
> "RCU or wq_pool_mutex should be held")
>
> -#define assert_rcu_or_wq_mutex(wq) \
> - RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
> - !lockdep_is_held(&wq->mutex), \
> - "RCU or wq->mutex should be held")
> -
> #define assert_rcu_or_wq_mutex_or_pool_mutex(wq) \
> RCU_LOCKDEP_WARN(!rcu_read_lock_held() && \
> !lockdep_is_held(&wq->mutex) && \
> @@ -425,9 +420,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
> * ignored.
> */
> #define for_each_pwq(pwq, wq) \
> - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \
> - if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \
> - else
> + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \
> + lockdep_is_held(&(wq->mutex)))
>
> #ifdef CONFIG_DEBUG_OBJECTS_WORK
>
> --
> 2.23.0.rc1.153.gdeed80330f-goog
>
prev parent reply other threads:[~2019-08-16 16:46 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-15 14:18 [PATCH v3 -rcu] workqueue: Convert for_each_wq to use built-in list check Joel Fernandes (Google)
2019-08-15 14:57 ` Matthew Wilcox
2019-08-15 15:24 ` Joel Fernandes
2019-08-16 16:45 ` Paul E. McKenney [this message]
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