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From: "H. Peter Anvin" <hpa@zytor.com>
To: Jonathan Lim <jlim@sgi.com>
Cc: linux-kernel@vger.kernel.org, jlan@sgi.com
Subject: Re: [PATCH] Provide u64 version of jiffies_to_usecs() in kernel/tsacct.c
Date: Fri, 28 Dec 2007 20:52:06 -0800	[thread overview]
Message-ID: <4775D276.7040301@zytor.com> (raw)
In-Reply-To: <200712282126.lBSLQ76K042714@sabah.engr.sgi.com>

Jonathan Lim wrote:
> It's possible that the values used in and returned from jiffies_to_usecs() are
> incorrect because of truncation when variables of type u64 are involved.  So a
> function specific to that type is used instead.

Much worse than that.  There are internal overflows in the conversions. 
See the patch I recently submitted to -mm.

	-hpa

  reply	other threads:[~2007-12-29  4:52 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-12-28 21:26 Jonathan Lim
2007-12-29  4:52 ` H. Peter Anvin [this message]
     [not found] <200801022103.m02L3oL1051764@sabah.engr.sgi.com>
2008-01-03  0:23 ` Andrew Morton
2008-01-03  0:36   ` H. Peter Anvin
2008-01-03  1:06     ` Jonathan Lim
2008-01-03  1:13       ` H. Peter Anvin
     [not found] <no.id>
2008-01-08  1:04 ` Jonathan Lim
2008-02-19 20:52 ` Jonathan Lim
2008-02-19 21:25   ` Randy Dunlap
2008-02-20  2:17     ` Jonathan Lim
2008-02-20  3:52       ` Randy Dunlap
2008-02-25 22:27 ` Jonathan Lim
2008-03-12 23:53   ` Roman Zippel
2008-04-18 21:54 ` Jonathan Lim
2008-02-15  2:27 Jonathan Lim

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