From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC] RSS guarantees and limits References: <20000622221923.A8744@redhat.com> From: "John Fremlin" Date: 22 Jun 2000 23:39:44 +0100 In-Reply-To: Stephen Tweedie's message of "Thu, 22 Jun 2000 22:19:23 +0100" Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Stephen Tweedie Cc: linux-mm@kvack.org List-ID: Stephen Tweedie writes: > On Thu, Jun 22, 2000 at 07:00:54PM +0100, John Fremlin wrote: > > > > > - protect smaller apps from bigger memory hogs > > > > Why? Yes, it's very altruistic, very sportsmanlike, but giving small, > > rarely used processes a form of social security is only going to > > increase bureaucracy ;-) > > It is critically important that when under memory pressure, a > system administrator can still log in and kill any runaway > processes. The smaller apps in question here are system daemons > such as init, inetd and telnetd, and user apps such as bash and > ps. We _must_ be able to allow them to make at least some > progress while the VM is under load. I agree completely. It was one of the reasons I suggested that a syscall like nice but giving info to the mm layer would be useful. In general, small apps (xeyes,biff,gpm) don't deserve any special treatment. I also said that on a multiuser system it is important that one user can't hog the system. In the case where it is impossible for a large app to drop root privileges being root wouldn't help unless an exception were made for admin caps. The only general solution I can see is to give some process (groups) a higher MM priority, by analogy with nice. It is critically important that an admin can login to kill a swarm of tiny runaway processes. A tiny program that forks every few seconds can bring down a machine just as, if not more effectively than, a couple of large runaways. [...] -- http://altern.org/vii -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux.eu.org/Linux-MM/