From: Christoph Lameter Subject: Re: [RFC 1/2] JBD: slab management support for large block(>8k) Date: Mon, 3 Sep 2007 12:31:49 -0700 (PDT) Message-ID: 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> <20070903134043.GB28962@infradead.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Mingming Cao , linux-fsdevel@vger.kernel.org, adilger@clusterfs.com, sho@tnes.nec.co.jp, ext4 development , linux-kernel@vger.kernel.org To: Christoph Hellwig Return-path: Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:50536 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751844AbXICTbu (ORCPT ); Mon, 3 Sep 2007 15:31:50 -0400 In-Reply-To: <20070903134043.GB28962@infradead.org> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon, 3 Sep 2007, Christoph Hellwig wrote: > > 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. So you'd be fine with replacing the allocs with get_free_pages(GFP_xxx, get_order(size)) ?