From: Christoph Hellwig Subject: Re: [RFC 1/2] JBD: slab management support for large block(>8k) Date: Mon, 3 Sep 2007 14:40:43 +0100 Message-ID: <20070903134043.GB28962@infradead.org> References: <20070828190551.415127746@sgi.com> <20070828190735.292638294@sgi.com> <1188432669.3799.35.camel@localhost.localdomain> <1188434857.3799.76.camel@localhost.localdomain> <1188605538.3837.51.camel@localhost.localdomain> <20070901183922.GA12907@infradead.org> <20070902152801.GA19962@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Mingming Cao , linux-fsdevel@vger.kernel.org, adilger@clusterfs.com, sho@tnes.nec.co.jp, ext4 development , linux-kernel@vger.kernel.org To: Christoph Lameter Return-path: Received: from pentafluge.infradead.org ([213.146.154.40]:48010 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbXICNkz (ORCPT ); Mon, 3 Sep 2007 09:40:55 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon, Sep 03, 2007 at 12:55:04AM -0700, Christoph Lameter wrote: > On Sun, 2 Sep 2007, Christoph Hellwig wrote: > > > > We are doing what you describe right now. So the current code is broken? > > Yes. > > How about getting rid of the slabs there and use kmalloc? Kmalloc in mm > (and therfore hopefully 2.6.24) will convert kmallocs > PAGE_SIZE to page > allocator calls. Not sure what to do about the 1k and 2k requests though. The problem is that we must never use kmalloc pages, so we always need to request a page or more for these. Better to use get_free_page directly, that's how I fixed it in XFS a while ago.