From owner-freebsd-current Sun Apr 11 16:52:35 1999 Delivered-To: freebsd-current@freebsd.org Received: from janus.syracuse.net (janus.syracuse.net [205.232.47.15]) by hub.freebsd.org (Postfix) with ESMTP id 13936153D6 for ; Sun, 11 Apr 1999 16:48:10 -0700 (PDT) (envelope-from green@unixhelp.org) Received: from localhost (green@localhost) by janus.syracuse.net (8.9.2/8.8.7) with ESMTP id TAA34660; Sun, 11 Apr 1999 19:45:40 -0400 (EDT) Date: Sun, 11 Apr 1999 19:45:39 -0400 (EDT) From: Brian Feldman X-Sender: green@janus.syracuse.net To: Kevin Day Cc: Warner Losh , dillon@apollo.backplane.com, hasty@rah.star-gate.com, dv@dv.ru, freebsd-current@FreeBSD.ORG Subject: Re: DoS from local users (fwd) In-Reply-To: <199904112247.RAA04823@home.dragondata.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, 11 Apr 1999, Kevin Day wrote: > > In message <199904102057.PAA27724@home.dragondata.com> Kevin Day writes: > > : i.e. uid 1001 starts 40 processes eating as much cpu as they can. Then uid > > : 1002 starts up one process. Uid 1002's process gets 50% cpu, and uid 1001's > > : 40 processes get 50% cpu shared between them. > > > > I've seen some experimental patches in the past that try to do just > > this. However, there are some problems. What if uid 1002's process > > does a sleep. Should the 40 processes that 1001 just get 50% of the > > cpu? Or should there be other limits. It turns into an interesting > > research problem in a hurry. > > > > Warner > > > > I was thinking essentially just processes in the RUN state get applied to > this. If the cpu would otherwise be sitting idle, by all means give it to > someone. But, if two users have processes running, just because one user has > 50 processes doesn't mean it should get 50x the cpu as one user who has one > process running. If a process is in sleep or blocked(select, IO, whatever), > it's taken out of consideration for the cpu, and the full cpu is given to > those processes that actually have work to do. > > > At least, that's my take on it. > > I run into this problem daily, and i get enough user complains of "User x > has 50 processes running, eating as much cpu as they can, my compile just > took 15 minutes". "What was their user name again?" *click xterm click* ps aux | grep ^user | wc -l "Hmm, you're right, fifty processes called 'cpuwaster'." rmuser user "They've been eliminated, thank you for letting us know of problems you have!" It's called "being a sysadmin". If someone's abusing the machine, delete em. > > > Kevin > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message > Brian Feldman _ __ ___ ____ ___ ___ ___ green@unixhelp.org _ __ ___ | _ ) __| \ FreeBSD: The Power to Serve! _ __ | _ \__ \ |) | http://www.freebsd.org _ |___/___/___/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message