Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752875AbYAWKET (ORCPT ); Wed, 23 Jan 2008 05:04:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751397AbYAWKEM (ORCPT ); Wed, 23 Jan 2008 05:04:12 -0500 Received: from an-out-0708.google.com ([209.85.132.249]:20211 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972AbYAWKEK convert rfc822-to-8bit (ORCPT ); Wed, 23 Jan 2008 05:04:10 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=EisQwEj3kXg4DVs0engNa89GQGmrMbVExn2TyzwCjG/ynmw2OrNOZyv033YqJELuq68F70q1wr+iuTmolXwa3JJrGnL9hjeBxMuIzf9dbD3CKKCzvb4dYxqUmtqGUXROWSt4Ae5AEmy3H/VhDDhG1cKnNsEugHEHjdXWqjTxF00= Message-ID: <9b06e8d20801230204t4450191eh996a9d45d3ec32a6@mail.gmail.com> Date: Wed, 23 Jan 2008 11:04:09 +0100 From: "=?ISO-8859-1?Q?Lo=EFc_Greni=E9?=" To: "Andi Kleen" Subject: Re: vmalloc_32 and SLAB incompatible in 2.6.23.9 Cc: linux-kernel@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Content-Disposition: inline References: <9b06e8d20801230114v1e09e5e8s6a4b438562c62619@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1536 Lines: 35 23 Jan 2008 10:35:28 +0100, Andi Kleen : > "Lo?c Greni?" writes: > > > Since GFP_DMA32 is not considered a valid flag, vmalloc_32 and > > SLAB are incompatible in kernel 2.6.23.9 (and probably later ones). > > It might be as simple as adding GFP_DMA32 everywhere where > > GFP_DMA is used in mm/slab.c, but I don't dare do it. I personally > > switched to SLUB. > > I don't think it would really work for slub either. > > If you look at /proc/slabinfo you see that there are separate DMA > caches. That is because sl[abo]b all cache objects and if the > objects have different requirements (like GFP_DMA, GFP_DMA32, GFP_KERNEL) > they would need different caches. Otherwise you risk getting > later objects originally allocated with the wrong flags. > > To make GFP_DMA32 work would require adding another set of DMA32 > caches to all kmalloc caches etc or a separate one for each > custom kmem cache that you use that only gets _DMA32 objects. > > Better just use __get_free_pages() directly. vmalloc_32 is using __vmalloc. I am much too ignorant to try and change anything in mm/*.[ch]. If vmalloc_32 is incompatible with sl[aou]b, should'nt it be either modified or removed ? Thanks, Lo?c Greni? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/