Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758606AbXFZQdu (ORCPT ); Tue, 26 Jun 2007 12:33:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754748AbXFZQdn (ORCPT ); Tue, 26 Jun 2007 12:33:43 -0400 Received: from mga09.intel.com ([134.134.136.24]:35445 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752356AbXFZQdn (ORCPT ); Tue, 26 Jun 2007 12:33:43 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.16,464,1175497200"; d="scan'208";a="100311301" Date: Tue, 26 Jun 2007 09:29:09 -0700 From: "Keshavamurthy, Anil S" To: Andrew Morton Cc: Christoph Lameter , "Keshavamurthy, Anil S" , linux-kernel@vger.kernel.org, ak@suse.de, gregkh@suse.de, muli@il.ibm.com, suresh.b.siddha@intel.com, arjan@linux.intel.com, ashok.raj@intel.com, davem@davemloft.net Subject: Re: [Intel IOMMU 05/10] Intel IOMMU driver Message-ID: <20070626162909.GD3374@linux-os.sc.intel.com> Reply-To: "Keshavamurthy, Anil S" References: <20070619213701.219910000@askeshav-devel.jf.intel.com> <20070619213808.716432000@askeshav-devel.jf.intel.com> <20070625233249.c17c41c3.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070625233249.c17c41c3.akpm@linux-foundation.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1409 Lines: 36 On Mon, Jun 25, 2007 at 11:32:49PM -0700, Andrew Morton wrote: > On Tue, 19 Jun 2007 16:32:23 -0700 (PDT) Christoph Lameter wrote: > > > On Tue, 19 Jun 2007, Keshavamurthy, Anil S wrote: > > > > > +static inline void *alloc_pgtable_page(void) > > > +{ > > > + return (void *)get_zeroed_page(GFP_ATOMIC); > > > +} > > > > Need to pass gfp_t parameter. Repeates a couple of times. > > ... > > Is it not possible here to drop the lock and do the alloc with GFP_KERNEL > > and deal with the resulting race? That is done in other parts of the > > kernel. > > ... > > This may be able to become a GFP_KERNEL alloc since interrupts are enabled > > at this point? > > ... > > GFP_KERNEL alloc possible? > > > > Yeah, if there are any callsites at all at which we know that we can > perform a sleeping allocation, Christoph's suggestions should be adopted. > Because even a bare GFP_NOIO is heaps more robust than GFP_ATOMIC, and it > will also reload the free-pages reserves, making subsequent GFP_ATOMIC > allocations more likely to succeed. Yup, will do as part of making this code work for IA64, which is my next item in my todo list. -Anil - 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/