From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Lameter Subject: Re: [00/41] Large Blocksize Support V7 (adds memmap support) Date: Tue, 11 Sep 2007 13:13:33 -0700 (PDT) Message-ID: References: <20070911060349.993975297@sgi.com> <200709110452.20363.nickpiggin@yahoo.com.au> <1189524967.32731.58.camel@localhost> <20070911164702.GD10831@v2.random> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Mel Gorman , Nick Piggin , torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Mel Gorman , William Lee Irwin III , David Chinner , Jens Axboe , Badari Pulavarty , Maxim Levitsky , Fengguang Wu , swin wang , totty.lu@gmail.com, hugh@veritas.com, joern@lazybastard.org To: Andrea Arcangeli Return-path: Received: from netops-testserver-4-out.sgi.com ([192.48.171.29]:57722 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S966642AbXIKUNf (ORCPT ); Tue, 11 Sep 2007 16:13:35 -0400 In-Reply-To: <20070911164702.GD10831@v2.random> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Tue, 11 Sep 2007, Andrea Arcangeli wrote: > But the whole point is that with the config_page_shift, Nick's worst > case scenario can't happen by design regardless of defrag or not > defrag. While it can _definitely_ happen with SGI design (regardless > of any defrag thing). We can still try to save some memory by > defragging the slab a bit, but it's by far *not* required with > config_page_shift. No defrag at all is required infact. Which worst case scenario? So far this is all a bit foggy. > Let's see how good the mmap support for variable order page size will > work after the 2 weeks... Yeah. Give us some failure scenarios please!