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From: Tejun Heo <tj@kernel.org>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Greg KH" <gregkh@suse.de>,
	"Américo Wang" <xiyou.wangcong@gmail.com>,
	"Neil Brown" <neilb@suse.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sysfs: differentiate between locking links and non-links
Date: Thu, 11 Feb 2010 11:10:38 +0900	[thread overview]
Message-ID: <4B73671E.2050105@kernel.org> (raw)
In-Reply-To: <m1ocjwwob1.fsf@fess.ebiederm.org>

Hello,

On 02/11/2010 10:31 AM, Eric W. Biederman wrote:
>> I think some code dynamically creates attributes today, as this has
>> never been a restriction.
>>
>> So I don't know if this is going to work :(
> 
> I need to see how locks do this, but they face the same problem.  For
> normal locks this is resolved by having a requirement to call a special
> initializer in the dynamic case.  Adding that requirement for the
> rare dynamically allocated sysfs attributes seems reasonable.

Yeah, this is the same problem all other constructus face too and the
reason why different variants of initializers are introduced for
lockdep support.  For dynamic ones, making the initializer declare
static key and using it to initialize lockdep_map should work.

> Additionally sysfs attributes are exactly the right granularity for
> lock classes because that is where the behavior is the same or
> changes.

Yeap.

> We have 845 instances of static struct attributes which certainly makes
> that the dominant case and worth aiming at.

Yeah, and sysfs will be following the usual convention of dealing with
these issues, which is the right thing to do.

Thanks.

-- 
tejun

  reply	other threads:[~2010-02-11  2:08 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-10  1:09 [PATCH] sysfs: differentiate between locking links and non-links Neil Brown
2010-02-10  1:21 ` David Rientjes
2010-02-10  1:56   ` Américo Wang
2010-02-10  3:05     ` David Rientjes
2010-02-10  3:14       ` Américo Wang
2010-02-10  3:19         ` David Rientjes
2010-02-10  3:33           ` Américo Wang
2010-02-10  2:08 ` Américo Wang
2010-02-10  2:19   ` Tejun Heo
2010-02-10  3:12     ` Américo Wang
2010-02-10  8:03     ` Eric W. Biederman
2010-02-10 10:39       ` Tejun Heo
2010-02-10 18:25         ` Eric W. Biederman
2010-02-10 23:05           ` Greg KH
2010-02-11  1:31             ` Eric W. Biederman
2010-02-11  2:10               ` Tejun Heo [this message]
2010-02-11 18:08                 ` Eric W. Biederman
2010-02-12  0:59                   ` Tejun Heo
2010-02-12  1:20                     ` Eric W. Biederman
2010-02-12  1:20                     ` Eric W. Biederman
2010-02-12  2:16                       ` Tejun Heo
2010-02-11 23:13                 ` [PATCH 0/4] Better sysfs lockdep Eric W. Biederman
2010-02-11 23:14                   ` [PATCH 1/4] sysfs: Remove sysfs_get/put_active_two Eric W. Biederman
2010-02-11 23:20                     ` [PATCH 2/4] sysfs: Only take active references on attributes Eric W. Biederman
2010-02-11 23:21                       ` [PATCH 3/4] sysfs: Use one lockdep class per sysfs attribute Eric W. Biederman
2010-02-11 23:23                         ` [PATCH 4/4] sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes Eric W. Biederman
2010-02-11 23:42                           ` Greg KH
2010-02-12 12:47                             ` [PATCH] sysfs: Document sysfs_attr_init and sysfs_bin_attr_init Eric W. Biederman
2010-02-12 21:41                               ` [PATCH] sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on module dynamic attributes Eric W. Biederman
2010-02-15 10:38                           ` [PATCH 4/4] sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on " Américo Wang
2010-02-15 12:53                             ` Eric W. Biederman
2010-02-15 10:35                         ` [PATCH 3/4] sysfs: Use one lockdep class per sysfs attribute Américo Wang
2010-02-15  7:27                       ` [PATCH 2/4] sysfs: Only take active references on attributes Américo Wang
2010-02-15  8:15                         ` Américo Wang
2010-02-15  8:31                           ` Américo Wang
2010-02-15 10:11                           ` Eric W. Biederman
2010-02-15  7:03                     ` [PATCH 1/4] sysfs: Remove sysfs_get/put_active_two Américo Wang
2010-02-11 23:18                   ` Eric W. Biederman
2010-02-11 23:17                 ` [PATCH 0/4] Better sysfs lockdep Eric W. Biederman
2010-02-11 23:43                   ` Greg KH
2010-02-10 23:54           ` [PATCH] sysfs: differentiate between locking links and non-links Tejun Heo
2010-02-11  0:38             ` Eric W. Biederman
2010-02-10 17:36 ` Eric W. Biederman
2010-02-10 17:55   ` Dmitry Torokhov
2010-02-10 23:06 ` Greg KH
2010-02-11 21:42   ` Eric W. Biederman
2010-02-11 22:32     ` Greg KH
2010-02-11 22:47       ` Eric W. Biederman
2010-02-17 22:38         ` Greg KH
2010-02-18  0:39           ` Neil Brown
2010-02-18  1:01             ` Eric W. Biederman
2010-02-18  1:12               ` Greg KH

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