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From: Andreas Schwab <schwab@suse.de>
To: linux-os@analogic.com
Cc: Linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: Possible spin-problem in nanosleep()
Date: Thu, 23 Jun 2005 14:33:52 +0200	[thread overview]
Message-ID: <jell516ymn.fsf@sykes.suse.de> (raw)
In-Reply-To: <Pine.LNX.4.61.0506230812160.15775@chaos.analogic.com> (Richard B. Johnson's message of "Thu, 23 Jun 2005 08:18:05 -0400 (EDT)")

"Richard B. Johnson" <linux-os@analogic.com> writes:

> nanosleep() appears to have a problem. It may be just an
> 'accounting' problem, but it isn't pretty. Code that used
> to use usleep() to spend most of it's time sleeping, used
> little or no CPU time as shown by `top`. The same code,
> converted to nanosleep() appears to spend a lot of CPU
> cycles spinning. The result is that `top` or similar
> programs show lots of wasted CPU time.

usleep() is just a wrapper around nanosleep().  Are you sure you got the
units right?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

  reply	other threads:[~2005-06-23 12:34 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-23 12:18 Possible spin-problem in nanosleep() Richard B. Johnson
2005-06-23 12:33 ` Andreas Schwab [this message]
2005-06-23 12:46   ` Richard B. Johnson
2005-06-23 15:09     ` Richard B. Johnson
2005-06-23 21:42       ` Alan Cox
2005-06-24 11:42         ` Richard B. Johnson
2005-06-26 17:18           ` Alan Cox
2005-06-26 18:14             ` Mike Galbraith
     [not found] <4iz0p-5fH-7@gated-at.bofh.it>
2005-06-23 23:39 ` Robert Hancock

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