From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [RFC 0/3] Recursive reclaim (on __PF_MEMALLOC) From: Peter Zijlstra In-Reply-To: References: <20070814142103.204771292@sgi.com> <1187102203.6114.2.camel@twins> Content-Type: text/plain Date: Tue, 14 Aug 2007 21:32:58 +0200 Message-Id: <1187119978.5337.1.camel@lappy> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 2007-08-14 at 08:29 -0700, Christoph Lameter wrote: > On Tue, 14 Aug 2007, Peter Zijlstra wrote: > > > On Tue, 2007-08-14 at 07:21 -0700, Christoph Lameter wrote: > > > The following patchset implements recursive reclaim. Recursive reclaim > > > is necessary if we run out of memory in the writeout patch from reclaim. > > > > > > This is f.e. important for stacked filesystems or anything that does > > > complicated processing in the writeout path. > > > > > > Recursive reclaim works because it limits itself to only reclaim pages > > > that do not require writeout. It will only remove clean pages from the LRU. > > > The dirty throttling of the VM during regular reclaim insures that the amount > > > of dirty pages is limited. > > > > No it doesn't. All memory can be tied up by anonymous pages - who are > > dirty by definition and are not clamped by the dirty limit. > > Ok but that could be addressed by making sure that a certain portion of > memory is reserved for clean file backed pages. Which gets us back to the initial problem of sizing this portion and ensuring it is big enough to service the need. -- 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