From: Kurt Wall <kwall@kurtwerks.com>
To: Jennifer Huang <carrothh@yahoo.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Question about cpu time accuracy.
Date: Sun, 12 May 2002 18:57:09 -0400 [thread overview]
Message-ID: <20020512185709.C623@marta> (raw)
In-Reply-To: <20020512223710.41173.qmail@web20109.mail.yahoo.com>
Scribbling feverishly on May 12, Jennifer Huang managed to emit:
> Hi all,
>
> I have a question about cpu time accuracy.
>
> I am using kernel 2.4.18. But, when I tried "utime"
> and "nanosleep" to get a process suspended, it only
> worked in 10ms granularity, and it's no way to sleep
> for 1 microsecond.
The standard kernel timer has a resolution of 1/HZ, which is 10ms on
an x86. You could try a scheduling policy of SCHED_FIFO or SCHED_RR,
but this only gets you 2ms resolution.
> Anyone can help me out of this?
There are patches available for high resolution timers:
http://sourceforge.net/projects/high-res-timers/
http://www.cs.wisc.edu/paradyn/libhrtime/
Kurt
--
Anarchy may not be the best form of government, but it's better than no
government at all.
next prev parent reply other threads:[~2002-05-12 22:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-05-12 22:37 Question about cpu time accuracy Jennifer Huang
2002-05-12 22:57 ` Kurt Wall [this message]
2002-05-13 2:49 ` Jennifer Huang
2002-05-13 3:22 ` Question about cpu time accuracy. Er resolution! george anzinger
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