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
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
>
--
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3C859909.30602@candelatech.com \
--to=greearb@candelatech.com \
--cc=davidel@xmailserver.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.