From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: x86 swiotlb questions Date: Fri, 15 Dec 2006 14:17:16 +0000 Message-ID: <4582BC7C.76E4.0078.0@novell.com> References: <4582B6CF.76E4.0078.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com, Keir Fraser List-Id: xen-devel@lists.xenproject.org >>> Keir Fraser 15.12.06 15:03 >>> >On 15/12/06 13:53, "Jan Beulich" wrote: > >> I already have patches ready to do this (the DMA thing really is a nice side >> effect, I mostly wanted it for 32on64, so that I can restrict domain >> allocations for 32-bit domains). Are you saying I should throw away the >> DMA specialization then altogether (I already have no special DMA heap >> anymore)? The leftovers from it are so that one can reserve some portion >> of low memory to be returned only when the width restriction is low enough >> (i.e. to retain dma_emergency_pool functionality), which certainly isn't >> really appropriate anymore now (it should rather be a percentage or >> something like that, so that the lower you get the more of the memory >> remains reserved for specialized allocations). > >I think dma_emergency_pool as is can go. Possibly it should be replaced by >allocator-management tools in dom0 to allow setting of limits on a >per-bitwidth basis. Okay, but I think I'll leave this as a separate change (that we probably first should reach agreement on what it really ought to do and not do). >Is this one of the patches you already sent in your 32-on-64 batch, or an >additional one? An additional one (or actually, a set of them, to make the individual steps more clear). As a followup, I'm also planning to get rid of the Xen heaps on those arches where they aren't needed (x86-64, not sure about ppc and ia64, but I would assume it's really only x86-32 that needs it). Jan