From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jes Sorensen Date: Wed, 13 Sep 2006 07:55:01 +0000 Subject: Re: [PATCH 0/8] Optional ZONE_DMA V1 Message-Id: List-Id: References: <20060911222729.4849.69497.sendpatchset@schroedinger.engr.sgi.com> In-Reply-To: <20060911222729.4849.69497.sendpatchset@schroedinger.engr.sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> "Christoph" = Christoph Lameter writes: Christoph> On Tue, 12 Sep 2006, Jack Steiner wrote: >> I'm missing something here. On Altix, currently ALL of the memory >> is reported as being in the DMA zone: >> >> % cat /proc/budd* Node 0, zone DMA 3015 116 4 1 ... Node 1, zone >> DMA 4243 355 15 3 ... Node 2, zone DMA 4384 113 6 4 ... >> >> % cat /proc/zoneinfo Node 0, zone DMA pages free 5868 ... >> >> The DMA slabs are empty, though. Christoph> This is wrong. All memory should be in ZONE_NORMAL since we Christoph> have no DMA restrictions on Altix. This is harmless on Altix because we have an IOMMU - however we should in theory put all memory below 4GB into the DMA32 zone (if there was any memory there :) to use if we ever ran out of IOMMU slots when running 32 bit only capable PCI devices. I've never seen this happen so it's purely theoretical. Cheers, Jes