From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Clark Williams <williams@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
LKML <linux-kernel@vger.kernel.org>,
RT <linux-rt-users@vger.kernel.org>
Subject: Re: [PATCH RT] rt: add rwsem_is_contended() definition to rwsem_rt.h
Date: Tue, 17 Feb 2015 11:09:11 +0100 [thread overview]
Message-ID: <20150217100911.GG26177@linutronix.de> (raw)
In-Reply-To: <20140827160928.6f323642@sluggy>
* Clark Williams | 2014-08-27 16:09:28 [-0500]:
>Thomas,
>
>The latest btrfs code uses rwsem_is_contended() in the function
>caching_thread(). On RT systems, include/linux/rwsem.h is replaced with
>include/linux/rwsem_rt.h which does not provide a definition for
>rwsem_is_contended(). This commit provides a definition that should
>work on RT (where the lock is actually an rt_mutex).
I see that I added rwsem_is_contended() in v3.14-rt1 which does:
|static inline int rwsem_is_contended(struct rw_semaphore *sem)
|{
| /* rt_mutex_has_waiters() */
| return !RB_EMPTY_ROOT(&sem->lock.waiters);
|}
Do you lack this in kernel prior to v3.14?
Sebastian
next prev parent reply other threads:[~2015-02-17 10:09 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-27 21:09 [PATCH RT] rt: add rwsem_is_contended() definition to rwsem_rt.h Clark Williams
2015-02-17 10:09 ` Sebastian Andrzej Siewior [this message]
2015-02-17 19:08 ` Clark Williams
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