Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753909Ab0KDFJG (ORCPT ); Thu, 4 Nov 2010 01:09:06 -0400 Received: from smtp-out.google.com ([216.239.44.51]:58021 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751263Ab0KDFJE (ORCPT ); Thu, 4 Nov 2010 01:09:04 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=C+iVjlMBgpCTnfez3ef5cqB1b8Ye2F1lo3fZQ/Etpvg7PDSxBbJgfpcCswKV+YSUXi lu3k+0K44Kinug+mBoHA== Date: Wed, 3 Nov 2010 22:08:56 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: "Figo.zhang" cc: figo zhang , lkml , "linux-mm@kvack.org" , Andrew Morton Subject: Re: Re:[PATCH v2]oom-kill: CAP_SYS_RESOURCE should get bonus In-Reply-To: <1288845730.2102.11.camel@myhost> Message-ID: References: <1288662213.10103.2.camel@localhost.localdomain> <1288827804.2725.0.camel@localhost.localdomain> <1288834737.2124.11.camel@myhost> <1288836733.2124.18.camel@myhost> <1288845730.2102.11.camel@myhost> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1757 Lines: 52 On Thu, 4 Nov 2010, Figo.zhang wrote: > CAP_SYS_RESOURCE == 1 means without resource limits just like a > superuser, > CAP_SYS_RESOURCE == 0 means hold resource limits, like normal user, > right? > Yes. > a new lower oom_score_adj will protect the process, right? > Yes. > Tasks without CAP_SYS_RESOURCE, means that it is not a superuser, why > user canot protect it by oom_score_adj? > Because, as I said, it would be trivial for a user program to deplete all memory (either intentionally or unintentioally) and cause every other task on the system to be oom killed as a result. That's an undesired result of a blatently obvious DoS. > like i want to protect my program such as gnome-terminal which is > without CAP_SYS_RESOURCE (have resource limits), > > [figo@myhost ~]$ ps -ax | grep gnome-ter > Warning: bad ps syntax, perhaps a bogus '-'? See > http://procps.sf.net/faq.html > 2280 ? Sl 0:01 gnome-terminal > 8839 pts/0 S+ 0:00 grep gnome-ter > [figo@myhost ~]$ cat /proc/2280/oom_adj > 3 > [figo@myhost ~]$ echo -17 > /proc/2280/oom_adj > bash: echo: write error: Permission denied > [figo@myhost ~]$ > > so, i canot protect my program. > If this is your system, you can either give yourself CAP_SYS_RESOURCE or do it through the superuser. This isn't exactly new, it's been the case for the past four years. I'm still struggling to find out the problem that you're trying to address with your various patches, perhaps because you haven't said what it is. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/