From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752271AbdJCPxT (ORCPT ); Tue, 3 Oct 2017 11:53:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50280 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751953AbdJCPxR (ORCPT ); Tue, 3 Oct 2017 11:53:17 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com BECF7C04AC7B Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=oleg@redhat.com Date: Tue, 3 Oct 2017 17:53:15 +0200 From: Oleg Nesterov To: akpm@linux-foundation.org Cc: adobriyan@gmail.com, ebiederm@xmission.com, keescook@chromium.org, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: + pid-delete-reserved_pids.patch added to -mm tree Message-ID: <20171003155314.GA9929@redhat.com> References: <59d2c819.FeJw+478bpKqle6W%akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <59d2c819.FeJw+478bpKqle6W%akpm@linux-foundation.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 03 Oct 2017 15:53:17 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Alexey, On 10/02, Andrew Morton wrote: > > From: Alexey Dobriyan > Subject: pid: delete RESERVED_PIDS > > RESERVED_PIDS had a noble goal: to protect root from PID exhaustion since > at least ~2.5.40 I am just curious, where did you find the change which documents this goal? > except it never did that because there was no capability > or uid checks. > > Allow small pids to be allocated after rollover, there is nothing sacred > about them. > > Resource exhaustion should be handled by rlimits and/or kernel memory > accounting. I won't argue, but I always thought that the only purpose of RESERVED_PIDS is to make the system/kernek daemons started at boot time more "visible" in /usr/bin/ps output. Oleg.