From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 16 Aug 2006 22:57:26 -0700 From: Andrew Morton Subject: Re: [RFC][PATCH 2/9] deadlock prevention core Message-Id: <20060816225726.3622cab1.akpm@osdl.org> In-Reply-To: <44E3E964.8010602@google.com> References: <20060808211731.GR14627@postel.suug.ch> <44DBED4C.6040604@redhat.com> <44DFA225.1020508@google.com> <20060813.165540.56347790.davem@davemloft.net> <44DFD262.5060106@google.com> <20060813185309.928472f9.akpm@osdl.org> <1155530453.5696.98.camel@twins> <20060813215853.0ed0e973.akpm@osdl.org> <44E3E964.8010602@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Daniel Phillips Cc: Peter Zijlstra , David Miller , riel@redhat.com, tgraf@suug.ch, linux-mm@kvack.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Mike Christie List-ID: On Wed, 16 Aug 2006 20:58:28 -0700 Daniel Phillips wrote: > Andrew Morton wrote: > > Peter Zijlstra wrote: > >>Testcase: > >> > >>Mount an NBD device as sole swap device and mmap > physical RAM, then > >>loop through touching pages only once. > > > > Fix: don't try to swap over the network. Yes, there may be some scenarios > > where people have no local storage, but it's reasonable to expect anyone > > who is using Linux as an "enterprise storage platform" to stick a local > > disk on the thing for swap. > > > > That leaves MAP_SHARED, but mm-tracking-shared-dirty-pages.patch will fix > > that, will it not? > > Hi Andrew, > > What happened to the case where we just fill memory full of dirty file > pages backed by a remote disk? > Processes which are dirtying those pages throttle at /proc/sys/vm/dirty_ratio% of memory dirty. So it is not possible to "fill" memory with dirty pages. If the amount of physical memory which is dirty exceeds 40%: bug. -- 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