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From: Viresh Kumar <viresh.kumar@linaro.org>
To: Nathan Zimmer <nzimmer@sgi.com>
Cc: rjw@sisk.pl, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 1/2] cpufreq: split the cpufreq_driver_lock and use the rcu
Date: Tue, 2 Apr 2013 10:35:46 +0530	[thread overview]
Message-ID: <CAKohpok7MR28trAddHRi5Lcg0bGBHBnOfJO=yu7SQqGnV5ZCRg@mail.gmail.com> (raw)
In-Reply-To: <1364847069-2887-2-git-send-email-nzimmer@sgi.com>

On 2 April 2013 01:41, Nathan Zimmer <nzimmer@sgi.com> wrote:
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c

> +static struct cpufreq_driver __rcu *cpufreq_driver;
> +static DEFINE_SPINLOCK(cpufreq_driver_lock);

You really need this lock? This is only used in cpufreq_register_driver
and unregister_driver... And it doesn't protect other routines at all. And
because we are using rcu stuff now, probably this lock is just not required.

> +static DEFINE_SPINLOCK(cpufreq_data_lock);

Only this one is required and it can be the rwlock which is already pushed
by rafael.

  reply	other threads:[~2013-04-02  5:05 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-04 22:45 [PATCH 0/2] cpufreq: cpufreq_driver_lock is hot on large systems Nathan Zimmer
2013-02-04 22:45 ` [PATCH 1/2] cpufreq: Convert the cpufreq_driver_lock to a rwlock Nathan Zimmer
2013-02-05  8:11   ` Viresh Kumar
2013-02-04 22:45 ` [PATCH 2/2] cpufreq: Convert the cpufreq_driver_lock to use the rcu Nathan Zimmer
2013-02-05  1:07 ` [PATCH 0/2] cpufreq: cpufreq_driver_lock is hot on large systems Rafael J. Wysocki
2013-02-05  8:28   ` Viresh Kumar
2013-02-05 10:03     ` Rafael J. Wysocki
2013-02-05  9:58       ` Viresh Kumar
2013-02-05 10:13         ` Rafael J. Wysocki
2013-02-05 14:58           ` Nathan Zimmer
2013-02-05 22:00             ` Rafael J. Wysocki
2013-02-06  2:04             ` [PATCH v2 linux-next " Nathan Zimmer
2013-02-06  2:04               ` [PATCH v2 linux-next 1/2] cpufreq: Convert the cpufreq_driver_lock to a rwlock Nathan Zimmer
2013-02-06  2:47                 ` Viresh Kumar
2013-02-06  2:04               ` [PATCH v2 linux-next 2/2] cpufreq: Convert the cpufreq_driver_lock to use the rcu Nathan Zimmer
2013-02-06  2:52                 ` Viresh Kumar
2013-02-06  8:51                   ` Viresh Kumar
2013-02-06 13:00                     ` Rafael J. Wysocki
2013-02-07 23:29                 ` Rafael J. Wysocki
2013-02-11 17:13                   ` Nathan Zimmer
2013-02-11 19:36                     ` Rafael J. Wysocki
2013-02-12  4:03                       ` Nathan Zimmer
2013-02-12 15:59                       ` Paul E. McKenney
2013-02-13 13:20                         ` Rafael J. Wysocki
2013-02-20 23:56               ` [PATCH v3 0/2] cpufreq: cpufreq_driver_lock is hot on large systems Nathan Zimmer
2013-02-20 23:56                 ` [PATCH v3 1/2] cpufreq: Convert the cpufreq_driver_lock to a rwlock Nathan Zimmer
2013-02-20 23:56                 ` [PATCH v3 2/2] cpufreq: Convert the cpufreq_driver_lock to use the rcu Nathan Zimmer
2013-02-21  5:50                   ` Viresh Kumar
2013-02-21 17:49                     ` Nathan Zimmer
2013-02-22 16:24                       ` [PATCH v4 0/2] cpufreq: cpufreq_driver_lock is hot on large systems Nathan Zimmer
2013-02-22 16:24                         ` [PATCH v4 1/2] cpufreq: Convert the cpufreq_driver_lock to a rwlock Nathan Zimmer
2013-02-23  3:57                           ` Viresh Kumar
2013-02-22 16:24                         ` [PATCH v4 2/2] cpufreq: Convert the cpufreq_driver_lock to use the rcu Nathan Zimmer
2013-02-23  3:39                           ` Viresh Kumar
2013-02-25 20:07                             ` Nathan Zimmer
2013-03-11 23:23                         ` [PATCH v4 0/2] cpufreq: cpufreq_driver_lock is hot on large systems Rafael J. Wysocki
2013-03-13 20:50                           ` Nathan Zimmer
2013-04-01 15:33                             ` [PATCH v5] cpufreq: split the cpufreq_driver_lock and use the rcu (was cpufreq: cpufreq_driver_lock is hot on large systems) Nathan Zimmer
2013-04-01 16:28                               ` Viresh Kumar
2013-04-01 17:17                                 ` Nathan Zimmer
2013-04-01 20:11                                   ` [PATCH v6 0/2] cpufreq: cpufreq_driver_lock is hot on large systems Nathan Zimmer
2013-04-01 20:11                                     ` [PATCH v6 1/2] cpufreq: split the cpufreq_driver_lock and use the rcu Nathan Zimmer
2013-04-02  5:05                                       ` Viresh Kumar [this message]
2013-04-02 14:55                                         ` Nathan Zimmer
2013-04-02 14:59                                           ` Viresh Kumar
2013-04-02 15:40                                             ` Nathan Zimmer
2013-04-02 15:52                                               ` Viresh Kumar
2013-04-02 22:57                                             ` Rafael J. Wysocki
2013-04-03  5:25                                               ` Viresh Kumar
2013-04-01 20:11                                     ` [PATCH v6 2/2] cpufreq: covert the cpufreq_data_lock to a spinlock Nathan Zimmer
2013-04-01 20:41                                       ` Rafael J. Wysocki
2013-04-02  0:56                                         ` Nathan Zimmer
2013-04-02  5:04                                           ` Viresh Kumar
2013-04-02 12:48                                             ` Rafael J. Wysocki
2013-04-02 14:58                                               ` Nathan Zimmer

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