From owner-freebsd-current@FreeBSD.ORG Thu Sep 23 19:37:51 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E6AF216A4FD for ; Thu, 23 Sep 2004 19:37:51 +0000 (GMT) Received: from smtp14.wxs.nl (smtp14.wxs.nl [195.121.6.28]) by mx1.FreeBSD.org (Postfix) with ESMTP id 931D543D48 for ; Thu, 23 Sep 2004 19:37:51 +0000 (GMT) (envelope-from ronald-freebsd8@klop.yi.org) Received: from ronald.echteman.nl (ip51cdc5d2.speed.planet.nl [81.205.197.210]) by smtp14.wxs.nlSMTP id <0I4I006FAEJ2GY@smtp14.wxs.nl> for freebsd-current@freebsd.org; Thu, 23 Sep 2004 21:37:50 +0200 (CEST) Received: (qmail 2148 invoked from network); Thu, 23 Sep 2004 19:37:49 +0000 Received: from unknown (HELO laptop.thuis.klop.ws) (192.168.1.4) by ronald.echteman.nl with SMTP; Thu, 23 Sep 2004 19:37:49 +0000 Received: (qmail 30647 invoked from network); Thu, 23 Sep 2004 19:36:50 +0000 Received: from unknown (HELO guido.thuis.klop.ws) (192.168.0.2) by 192.168.0.16 with SMTP; Thu, 23 Sep 2004 19:36:50 +0000 Received: (qmail 79076 invoked from network); Thu, 23 Sep 2004 19:37:23 +0000 Received: from localhost.thuis.klop.ws (HELO outgoing.local) (127.0.0.1) by localhost.thuis.klop.ws with SMTP; Thu, 23 Sep 2004 19:37:23 +0000 Date: Thu, 23 Sep 2004 21:37:22 +0200 From: Ronald Klop In-reply-to: To: Juha Saarinen , "David G. Lawrence" Message-id: MIME-version: 1.0 Content-type: text/plain; format=flowed; delsp=yes; charset=iso-8859-1 Content-transfer-encoding: 7BIT User-Agent: Opera M2/7.54 (FreeBSD, build 751) References: <20040923122620.GW16205@nexus.dglawrence.com> X-Mailman-Approved-At: Fri, 24 Sep 2004 12:05:54 +0000 cc: freebsd-current@freebsd.org Subject: Re: Could ARG_MAX be increased? X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Sep 2004 19:37:52 -0000 On Fri, 24 Sep 2004 07:27:18 +1200, Juha Saarinen wrote: > On Thu, 23 Sep 2004 05:26:20 -0700, David G. Lawrence > wrote: >> I feel compelled to respond since you mentioned me above and since I >> wrote most of the code involved... :-) >> The main issue with increasing the size of ARG_MAX is that it will >> result >> in more kernel virtual memory being reserved for temporary storage of >> the >> args. This used to be a much larger problem when KVM was scarce, but >> less >> of a problem now with 1GB or more of KVM. The args temporary space is >> allocated out of exec_map (a submap of kernel_map), which is sized to be >> about 16 * ARG_MAX. The '16' is to allow up to 16 processes to >> simultaneously >> exec until additional execs are blocked waiting for KVM to become >> available. Anyway, increasing ARG_MAX to 256K (roughly 4MB of KVM) >> should >> be okay on most systems. Can't it be made dependend on kern.maxusers which is dependend on the max amount of memory available? So people with low memory aren't wasting a lot of memory? Ronald. -- Ronald Klop Amsterdam, The Netherlands