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Message-ID: <2c0942db0603240922u7bade58lcf2a6af2af8ec6ae@mail.gmail.com>
Date: Fri, 24 Mar 2006 09:22:51 -0800
From: "Ray Lee" <madrabbit@gmail.com>
Reply-To: ray-gmail@madrabbit.org
To: "Andreas Mohr" <andi@rhlx01.fht-esslingen.de>
Subject: Re: delay_tsc(): inefficient delay loop (2.6.16-mm1)
Cc: lkml <linux-kernel@vger.kernel.org>, "john stultz" <johnstul@us.ibm.com>,
       "Dominik Brodowski" <linux@brodo.de>
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On 3/24/06, Andreas Mohr <andi@rhlx01.fht-esslingen.de> wrote:
> +       loops += bclock;
[...]
> -       } while ((now-bclock) < loops);
> +       } while (now < loops);

Erm, aren't you introducing an overflow problem here?

if loops is 2^32-1, bclock is 1, the old version would execute the
proper number of times, the new one will blow out in one tick.
-
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