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Date:      Tue, 30 Jan 2007 09:26:34 -0600
From:      Dan Nelson <dnelson@allantgroup.com>
To:        waldeck@gmx.de
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: top delay value
Message-ID:  <20070130152633.GF19656@dan.emsphone.com>
In-Reply-To: <20070130140227.26613101832@hk2.uwaterloo.ca>
References:  <20070130140227.26613101832@hk2.uwaterloo.ca>

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In the last episode (Jan 30), waldeck@gmx.de said:
> An unprivileged user could waste all CPU time by setting a low delay
> value in top (interactive or via -s).

Are you sure?  In 6.2 at least, "s0" in interactive mode results in a
1-second delay, and "top -s0" prints

 top: warning: seconds delay should be positive -- using default
 ....

What version of FreeBSD are you seeing this on?

> Is there any possibility to deactivate this functionality without
> recompilation?
> 
> There are other top implementations that use a "secure mode"
> configuration which avoids the setting of the delay value for
> unprivileged users.

Users can hog CPU by running "while true ; do done" or any number of
other methods.  That's what CPU limits are for :)

-- 
	Dan Nelson
	dnelson@allantgroup.com



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