From: Ben Greear <greearb@candelatech.com>
To: Davide Libenzi <davidel@xmailserver.org>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: a faster way to gettimeofday?
Date: Tue, 05 Mar 2002 21:20:25 -0700 [thread overview]
Message-ID: <3C859909.30602@candelatech.com> (raw)
In-Reply-To: <Pine.LNX.4.44.0203051955090.1475-100000@blue1.dev.mcafeelabs.com>
Davide Libenzi wrote:
> On Tue, 5 Mar 2002, Ben Greear wrote:
>
>
>>I have a program that I very often need to calculate the current
>>time, with milisecond accuracy. I've been using gettimeofday(),
>>but gprof shows it's taking a significant (10% or so) amount of
>>time. Is there a faster (and perhaps less portable?) way to get
>>the time information on x86? My program runs as root, so should
>>have any permissions it needs to use some backdoor hack if that
>>helps!
>>
>
> If you're on x86 you can use collect rdtsc samples and convert them to ms.
> You'll get even more then ms accuracy.
Can I do this from user space? If so, any examples or docs
you can point me to?
Also, I'm looking primarily for a speed increase, not an accuracy
increase.
Thanks for the response!
Ben
>
>
>
>
> - Davide
>
>
>
> -
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--
Ben Greear <greearb@candelatech.com> <Ben_Greear AT excite.com>
President of Candela Technologies Inc http://www.candelatech.com
ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear
next prev parent reply other threads:[~2002-03-06 4:20 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-03-06 3:41 a faster way to gettimeofday? Ben Greear
2002-03-06 3:58 ` Davide Libenzi
2002-03-06 4:20 ` Ben Greear [this message]
2002-03-06 4:31 ` Davide Libenzi
2002-03-06 4:34 ` Davide Libenzi
2002-03-07 14:14 ` a faster way to gettimeofday? rdtsc strangeness Terje Eggestad
2002-03-07 14:41 ` Alan Cox
2002-03-07 15:43 ` Terje Eggestad
2002-03-07 16:17 ` Alan Cox
2002-03-07 18:32 ` H. Peter Anvin
2002-03-08 1:32 ` Jamie Lokier
2002-03-08 1:35 ` H. Peter Anvin
2002-03-08 1:57 ` Jamie Lokier
2002-03-08 18:30 ` gettimeofday() system call timing curiosity Jamie Lokier
2002-03-08 18:50 ` H. Peter Anvin
2002-03-08 20:16 ` Jamie Lokier
2002-03-08 20:30 ` Davide Libenzi
2002-03-08 18:54 ` Richard B. Johnson
2002-03-08 19:06 ` johan.adolfsson
2002-03-08 19:16 ` H. Peter Anvin
2002-03-08 19:45 ` Richard B. Johnson
2002-03-08 20:29 ` johan.adolfsson
2002-03-08 20:43 ` Alan Cox
2002-03-09 3:03 ` pjd
2002-03-09 18:51 ` Alan Cox
2002-03-09 3:15 ` Kelsey Hudson
2002-03-08 19:19 ` Alan Cox
2002-03-08 20:40 ` george anzinger
2002-03-06 20:45 ` a faster way to gettimeofday? dean gaudet
2002-03-06 21:31 ` Chris Ball
2002-03-06 22:25 ` george anzinger
2002-03-07 0:04 ` vsyscalls Mark Mielke
2002-03-06 16:16 ` a faster way to gettimeofday? Chris Friesen
2002-03-06 16:54 ` Richard B. Johnson
2002-03-11 22:47 ` OBATA Noboru
2002-03-12 13:06 ` Jamie Lokier
2002-03-12 15:12 ` OBATA Noboru
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