Message-ID: <51A6EF57.8020507@acm.org>
Date: Thu, 30 May 2013 08:19:03 +0200
From: Bart Van Assche <bvanassche@acm.org>
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To: Andrew Morton <akpm@linux-foundation.org>
CC: Thomas Gleixner <tglx@linutronix.de>,
        Arjan van de Ven <arjan@infradead.org>,
        Stephen Rothwell <sfr@canb.auug.org.au>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Joe Perches <joe@perches.com>
Subject: Re: [PATCH] timer: Fix jiffies wrap behavior of round_jiffies*()
References: <519BC066.5080600@acm.org> <20130529160150.f0a498d188dc790d018200e9@linux-foundation.org>
In-Reply-To: <20130529160150.f0a498d188dc790d018200e9@linux-foundation.org>
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On 05/30/13 01:01, Andrew Morton wrote:
> On Tue, 21 May 2013 20:43:50 +0200 Bart Van Assche <bart.vanassche@gmail.com> wrote:
>
>> Make sure that the round_jiffies*() functions return a time that is
>> in the future when the jiffies counter is about to wrap.
>
> Actually "when the jiffies counter has recently wrapped".
>
> I assume this was found by inspection?

Hello Andrew,

You are correct, this was found via source code inspection. I started 
reviewing the round_jiffies*() implementation because I was chasing a 
bug in a kernel driver using one of these functions.

>> -		return original;
>> -	return j;
>> +	return time_is_after_jiffies(j) ? j : original;
>>   }
>
> Your email client mangles patches, btw.

Sorry. Will take more care in the future.

Bart.

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