From: Thomas Gleixner <tglx@linutronix.de>
To: george@mvista.com
Cc: john stultz <johnstul@us.ibm.com>,
Roman Zippel <zippel@linux-m68k.org>,
linux-kernel@vger.kernel.org
Subject: Re: new time code problem
Date: Wed, 11 Jan 2006 00:23:34 +0000 [thread overview]
Message-ID: <200601110023.35374.tglx@linutronix.de> (raw)
In-Reply-To: <43C44A3C.6010803@mvista.com>
On Tuesday 10 January 2006 23:58, George Anzinger wrote:
> The 64-bit conversion routine to convert 64-bit nsec time to a time spec.
> gives an unnormalized result if the value being converted is negative. I
> think there are two ways to go about fixing this. Most systems will give a
> negative remainder and so need to just normalize. On the other hand, some
> systems will use div64 to do the division and, I think, it expects unsigned
> numbers. The attached patch uses the conservative approach of expecting
> the div to be set up for unsigned numbers.
>
> I came accross this when one of my tests set a time near 1 Jan 1970, i.e.
> it is a real problem.
>
> kernel/time.c | 13 ++++++++-----
> 1 files changed, 8 insertions(+), 5 deletions(-)
>
> Index: linux-2.6.16-rc/kernel/time.c
> ===================================================================
> --- linux-2.6.16-rc.orig/kernel/time.c
> +++ linux-2.6.16-rc/kernel/time.c
> @@ -702,16 +702,19 @@ void set_normalized_timespec(struct time
> *
> * Returns the timespec representation of the nsec parameter.
> */
> -inline struct timespec ns_to_timespec(const nsec_t nsec)
> +struct timespec ns_to_timespec(const nsec_t nsec)
> {
> struct timespec ts;
>
> - if (nsec)
> + if (nsec) return (struct timespec){0, 0};
Err, you mean propably
if(!nsec)
return (struct timespec){0, 0};
tglx
next prev parent reply other threads:[~2006-01-11 0:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-12-21 23:20 [PATCH 1/10] NTP: Remove pps support Roman Zippel
2006-01-10 23:20 ` john stultz
2006-01-10 23:58 ` new time code problem George Anzinger
2006-01-11 0:23 ` Thomas Gleixner [this message]
2006-01-11 1:37 ` George Anzinger
2006-01-11 9:18 ` [PATCH 1/10] NTP: Remove pps support Ulrich Windl
2006-01-12 11:58 ` Roman Zippel
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