From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751674AbaDATTX (ORCPT ); Tue, 1 Apr 2014 15:19:23 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:36350 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751310AbaDATTV (ORCPT ); Tue, 1 Apr 2014 15:19:21 -0400 Date: Tue, 1 Apr 2014 12:19:20 -0700 From: Andrew Morton To: Kamezawa Hiroyuki Cc: Davidlohr Bueso , Manfred Spraul , aswin@hp.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, KOSAKI Motohiro , "Gotou, Yasunori" , chenhanxiao , Gao feng Subject: Re: [PATCH] ipc,shm: increase default size for shmmax Message-Id: <20140401121920.50d1dd96c2145acc81561b82@linux-foundation.org> In-Reply-To: <533A5CB1.1@jp.fujitsu.com> References: <1396235199.2507.2.camel@buesod1.americas.hpqcorp.net> <20140331143217.c6ff958e1fd9944d78507418@linux-foundation.org> <1396306773.18499.22.camel@buesod1.americas.hpqcorp.net> <20140331161308.6510381345cb9a1b419d5ec0@linux-foundation.org> <1396308332.18499.25.camel@buesod1.americas.hpqcorp.net> <20140331170546.3b3e72f0.akpm@linux-foundation.org> <533A5CB1.1@jp.fujitsu.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 01 Apr 2014 15:29:05 +0900 Kamezawa Hiroyuki wrote: > > > > So their system will act as if they had set SHMMAX=enormous. What > > problems could that cause? > > > > > > Look. The 32M thing is causing problems. Arbitrarily increasing the > > arbitrary 32M to an arbitrary 128M won't fix anything - we still have > > the problem. Think bigger, please: how can we make this problem go > > away for ever? > > > > Our middleware engineers has been complaining about this sysctl limit. > System administrator need to calculate required sysctl value by making sum > of all planned middlewares, and middleware provider needs to write "please > calculate systcl param by....." in their installation manuals. Why aren't people just setting the sysctl to a petabyte? What problems would that lead to? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f182.google.com (mail-pd0-f182.google.com [209.85.192.182]) by kanga.kvack.org (Postfix) with ESMTP id C5B456B0037 for ; Tue, 1 Apr 2014 15:19:22 -0400 (EDT) Received: by mail-pd0-f182.google.com with SMTP id y10so10002748pdj.13 for ; Tue, 01 Apr 2014 12:19:22 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTP id cb4si6570355pbc.280.2014.04.01.12.19.21 for ; Tue, 01 Apr 2014 12:19:21 -0700 (PDT) Date: Tue, 1 Apr 2014 12:19:20 -0700 From: Andrew Morton Subject: Re: [PATCH] ipc,shm: increase default size for shmmax Message-Id: <20140401121920.50d1dd96c2145acc81561b82@linux-foundation.org> In-Reply-To: <533A5CB1.1@jp.fujitsu.com> References: <1396235199.2507.2.camel@buesod1.americas.hpqcorp.net> <20140331143217.c6ff958e1fd9944d78507418@linux-foundation.org> <1396306773.18499.22.camel@buesod1.americas.hpqcorp.net> <20140331161308.6510381345cb9a1b419d5ec0@linux-foundation.org> <1396308332.18499.25.camel@buesod1.americas.hpqcorp.net> <20140331170546.3b3e72f0.akpm@linux-foundation.org> <533A5CB1.1@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Kamezawa Hiroyuki Cc: Davidlohr Bueso , Manfred Spraul , aswin@hp.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, KOSAKI Motohiro , "Gotou, Yasunori" , chenhanxiao , Gao feng On Tue, 01 Apr 2014 15:29:05 +0900 Kamezawa Hiroyuki wrote: > > > > So their system will act as if they had set SHMMAX=enormous. What > > problems could that cause? > > > > > > Look. The 32M thing is causing problems. Arbitrarily increasing the > > arbitrary 32M to an arbitrary 128M won't fix anything - we still have > > the problem. Think bigger, please: how can we make this problem go > > away for ever? > > > > Our middleware engineers has been complaining about this sysctl limit. > System administrator need to calculate required sysctl value by making sum > of all planned middlewares, and middleware provider needs to write "please > calculate systcl param by....." in their installation manuals. Why aren't people just setting the sysctl to a petabyte? What problems would that lead to? -- 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-mm.org/ . Don't email: email@kvack.org