From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 02 Jun 2005 21:49:27 -0700 (PDT) Message-Id: <20050602.214927.59657656.davem@davemloft.net> Subject: Re: Avoiding external fragmentation with a placement policy Version 12 From: "David S. Miller" In-Reply-To: <1117770488.5084.25.camel@npiggin-nld.site> References: <429E50B8.1060405@yahoo.com.au> <429F2B26.9070509@austin.ibm.com> <1117770488.5084.25.camel@npiggin-nld.site> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org From: Nick Piggin Date: Fri, 03 Jun 2005 13:48:08 +1000 Return-Path: To: nickpiggin@yahoo.com.au Cc: jschopp@austin.ibm.com, mbligh@mbligh.org, mel@csn.ul.ie, linux-mm@kvack.org, linux-kernel@vger.kernel.org, akpm@osdl.org List-ID: > It would really help your cause in the short term if you can > demonstrate improvements for say order-3 allocations (eg. use > gige networking, TSO, jumbo frames, etc). TSO chops up the user data into PAGE_SIZE chunks, it doesn't make use of non-zero page orders. AF_UNIX sockets, however, will happily use higher order pages. But even this is limited to SKB_MAX_ORDER which is currently defined to 2. So the only way to get order 3 or larger allocations with the networking is to use jumbo frames but without TSO enabled. Actually, even with TSO enabled, you'll get large order allocations, but for receive packets, and these allocations happen in software interrupt context. -- 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