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From: Arjan van de Ven <arjan@infradead.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@redhat.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Kernel development list <linux-kernel@vger.kernel.org>
Subject: Re: (BUG?) round_jiffies() is non-monotonic on SMP
Date: Sat, 1 Nov 2008 19:43:57 -0700	[thread overview]
Message-ID: <20081101194357.1810f57a@infradead.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0811012234590.30060-100000@netrider.rowland.org>

On Sat, 1 Nov 2008 22:36:30 -0400 (EDT)
Alan Stern <stern@rowland.harvard.edu> wrote:

> On Sat, 1 Nov 2008, Arjan van de Ven wrote:
> 
> > > Come to think of it, is there any good reason why
> > > round_jiffies() doesn't always round up?  It seems a lot safer.
> > 
> > at the time folks had concerns about making a big error in that
> > direction...
> 
> All right then.  Would it be preferable to add a new
> round_jiffies_up() routine, or to change round_jiffies() so that it
> never rounds down?

I'd prefer the former.
But to be honest.. I would even more prefer the use of range timers ;)
They're in 2.6.28-rc now ... and more power friendly than rounded timers
(although I will readily admit that rounding is just easier)



-- 
Arjan van de Ven 	Intel Open Source Technology Centre
For development, discussion and tips for power savings, 
visit http://www.lesswatts.org

  reply	other threads:[~2008-11-02  2:43 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-11-01 16:14 Alan Stern
2008-11-01 16:29 ` Arjan van de Ven
2008-11-01 19:54   ` Alan Stern
2008-11-01 20:16     ` Arjan van de Ven
2008-11-02  2:36       ` Alan Stern
2008-11-02  2:43         ` Arjan van de Ven [this message]
2008-11-02 15:39           ` Alan Stern

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