From: Tharindu Rukshan Bamunuarachchi Subject: Re: TMPFS over NFSv4 Date: Mon, 24 May 2010 12:36:49 +0100 Message-ID: References: <20100524110245.6b6d847d@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Cc: Hugh Dickins , linux-mm@kvack.org, linux-nfs@vger.kernel.org To: Alan Cox Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:40369 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755361Ab0EXLhV convert rfc822-to-8bit (ORCPT ); Mon, 24 May 2010 07:37:21 -0400 Received: by iwn6 with SMTP id 6so3424071iwn.19 for ; Mon, 24 May 2010 04:37:20 -0700 (PDT) In-Reply-To: <20100524110245.6b6d847d@lxorguk.ukuu.org.uk> Sender: linux-nfs-owner@vger.kernel.org List-ID: Got it cleared. BTW, nice example ... US Banking System :-) __ tharindu.info "those that can, do. Those that can=92t, complain." -- Linus On Mon, May 24, 2010 at 11:02 AM, Alan Cox w= rote: > On Mon, 24 May 2010 10:26:39 +0100 > Tharindu Rukshan Bamunuarachchi wrote: > >> thankx a lot Hugh ... I will try this out ... (bit harder patch >> already patched SLES kernel :-p ) .... >> >> BTW, what does Alan means by "strict overcommit" ? > > Strict overcommit works like banks should. It tries to ensure that at= any > point it has sufficient swap and memory to fulfill any possible use o= f > allocated address space. So in strict overcommit mode you should almo= st > never see an OOM kill (there are perverse cases as always), but you w= ill > need a lot more swap that may well never be used. > > In the normal mode the kernel works like the US banking system and ma= kes > speculative guesses that all the resources it hands out will never be > needed at once. That has the corresponding risk that one day it might= at > which point you get a meltdown (or in the kernel case OOM kills) > > Alan >