From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267212AbUJBCaO (ORCPT ); Fri, 1 Oct 2004 22:30:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267232AbUJBCaO (ORCPT ); Fri, 1 Oct 2004 22:30:14 -0400 Received: from mail-13.iinet.net.au ([203.59.3.45]:14483 "HELO mail.iinet.net.au") by vger.kernel.org with SMTP id S267212AbUJBCaI (ORCPT ); Fri, 1 Oct 2004 22:30:08 -0400 Message-ID: <415E12A9.7000507@cyberone.com.au> Date: Sat, 02 Oct 2004 12:30:01 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040820 Debian/1.7.2-4 X-Accept-Language: en MIME-Version: 1.0 To: Marcelo Tosatti CC: linux-mm@kvack.org, akpm@osdl.org, arjanv@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [RFC] memory defragmentation to satisfy high order allocations References: <20041001182221.GA3191@logos.cnet> In-Reply-To: <20041001182221.GA3191@logos.cnet> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Marcelo Tosatti wrote: > >With such a thing in place we can build a mechanism for kswapd >(or a separate kernel thread, if needed) to notice when we are low on >high order pages, and use the coalescing algorithm instead blindly >freeing unique pages from LRU in the hope to build large physically >contiguous memory areas. > >Comments appreciated. > > Hi Marcelo, Seems like a good idea... even with regular dumb kswapd "merging", you may easily get stuck for example on systems without swap... Anyway, I'd like to get those beat kswapd patches in first. Then your mechanism just becomes something like: if order-0 pages are low { try to free memory } else if order-1 or higher pages are low { try to coalesce_memory if that fails, try to free memory } From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <415E12A9.7000507@cyberone.com.au> Date: Sat, 02 Oct 2004 12:30:01 +1000 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [RFC] memory defragmentation to satisfy high order allocations References: <20041001182221.GA3191@logos.cnet> In-Reply-To: <20041001182221.GA3191@logos.cnet> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Marcelo Tosatti Cc: linux-mm@kvack.org, akpm@osdl.org, arjanv@redhat.com, linux-kernel@vger.kernel.org List-ID: Marcelo Tosatti wrote: > >With such a thing in place we can build a mechanism for kswapd >(or a separate kernel thread, if needed) to notice when we are low on >high order pages, and use the coalescing algorithm instead blindly >freeing unique pages from LRU in the hope to build large physically >contiguous memory areas. > >Comments appreciated. > > Hi Marcelo, Seems like a good idea... even with regular dumb kswapd "merging", you may easily get stuck for example on systems without swap... Anyway, I'd like to get those beat kswapd patches in first. Then your mechanism just becomes something like: if order-0 pages are low { try to free memory } else if order-1 or higher pages are low { try to coalesce_memory if that fails, try to free memory } -- 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: aart@kvack.org