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From: Tejun Heo <tj@kernel.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: Lockdep false positive in sysfs
Date: Wed, 9 May 2012 10:41:14 -0700	[thread overview]
Message-ID: <20120509174114.GE24636@google.com> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1205081448590.1164-100000@iolanthe.rowland.org>

Hello,

On Tue, May 08, 2012 at 02:53:11PM -0400, Alan Stern wrote:
> On Mon, 7 May 2012, Tejun Heo wrote:
> 
> > On Mon, May 07, 2012 at 05:51:52PM -0400, Alan Stern wrote:
> > > I guess in the end it's a question of balance.  Which has more 
> > > overhead, adding a few function calls here and there, or adding a new 
> > > flags field to every struct attribute?
> > 
> > Yes, and there are different types of overheads.  I'm happy to trade
> > some runtime memory overhead under debugging mode for lower code
> > complexity.  Lock proving is pretty expensive anyway.  I don't think
> > there's much point in trying to optimize some bytes from struct
> > attributes.
> 
> Okay, then what do you think about this approach?  It does seem smaller 
> and simpler than the previous attempt.
> 
> And I did try to avoid unnecessary bloat; if lockdep isn't being used
> then the extra attribute flag isn't present.

Yeap, looks good to me.

Thanks.

-- 
tejun

  reply	other threads:[~2012-05-09 17:41 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-25 18:58 Lockdep false positive in sysfs Alan Stern
2012-04-25 21:59 ` Tejun Heo
2012-04-26  8:16   ` Eric W. Biederman
2012-04-26 18:14     ` Alan Stern
2012-04-26 22:17       ` Tejun Heo
2012-04-27 15:57         ` Alan Stern
2012-04-27 16:09           ` Tejun Heo
2012-05-03 21:30             ` Alan Stern
2012-05-04 16:52               ` Tejun Heo
2012-05-04 19:08                 ` Alan Stern
2012-05-07 19:46                   ` Tejun Heo
2012-05-07 21:51                     ` Alan Stern
2012-05-07 21:55                       ` Tejun Heo
2012-05-08 18:53                         ` Alan Stern
2012-05-09 17:41                           ` Tejun Heo [this message]
2012-05-09 17:47                             ` Alan Stern
2012-05-09 17:48                               ` Tejun Heo
2012-04-27 16:27           ` Eric W. Biederman
2012-04-27 18:27             ` Alan Stern
2012-04-27 20:17               ` Tejun Heo
2012-04-27 21:09                 ` Eric W. Biederman
2012-04-27 21:16                   ` Tejun Heo
2012-04-29  2:00                   ` Alan Stern
2012-04-29  2:35                     ` Eric W. Biederman

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