From: William Heimbigner <icxcnika@mar.tar.cc>
To: Lee Revell <rlrevell@joe-job.com>
Cc: tglx@linutronix.de, matthieu castet <castet.matthieu@free.fr>,
Linux Kernel list <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: High Resolution Timer DOS
Date: Sat, 28 Apr 2007 22:45:03 +0000 (GMT) [thread overview]
Message-ID: <Pine.LNX.4.64.0704282244130.25153@server.thyself> (raw)
In-Reply-To: <75b66ecd0704281537s54134967ybc3ddef0b87b6bf5@mail.gmail.com>
On Sat, 28 Apr 2007, Lee Revell wrote:
> On 4/28/07, Thomas Gleixner <tglx@linutronix.de> wrote:
>>
>> Well, it is not really a DoS. The rescheduling of the process is limited
>> by the scheduler and the available CPU time (depending on the number of
>> runnable tasks in the system).
>
> Shouldn't an unprivileged process be rate limited somehow to avoid
> flooding the machine with interrupts? We restrict nonroot users from
> setting the RTC interrupt rate higher than 64Hz for a similar reason
> (granted, this limit dates back to the 486 days and should probably be
> increased to 1024 Hz).
Isn't that what /etc/security/limits.conf is for?
Just limit the CPU usage.
> Root and SCHED_FIFO tasks could be exempt from rate limiting, to avoid
> the need to introduce a new rlimit which would take years for
> userspace to catch up to.
>
> Lee
William Heimbigner
icxcnika@mar.tar.cc
next prev parent reply other threads:[~2007-04-28 22:45 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-28 21:53 matthieu castet
2007-04-28 22:13 ` Thomas Gleixner
2007-04-28 22:37 ` Lee Revell
2007-04-28 22:45 ` William Heimbigner [this message]
2007-04-29 7:17 ` Ingo Molnar
2007-04-29 16:08 ` matthieu castet
2007-04-29 16:42 ` Ingo Molnar
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