On Wed, 28 Jul 2010 13:09:57 +0200 Andi Kleen <andi@xxxxxxxxxxxxxx> wrote: > FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> writes: > > > >> The other problem is that using only two bits for the needed address > >> space is also extremly > >> inefficient (4GB and 16MB on x86). Really want masks everywhere and > >> optimize for the > >> actual requirements. > > > > swiotlb doesn't allocate GFP_DMA memory. It handles only GFP_DMA32. > > I was lumping GFP_DMA and swiotlb together here. The > pci_alloc_consistent() function uses both interchangedly. > They really effectively are the same thing these days > and just separated by historical accident. Sorry, I meant to ZONE_DMA. You are talking about your dma mask allocation patchset, right? I meant that swiotlb doesn't need to handle ZONE_DMA. It handles only devices that can handle ZONE_DMA32. > > I have a half-baked patch for it. I'll send it later. > > The problem are still the *_map users which usually cannot sleep, > and then it's difficult to grow. Why we can't use GFP_NOWAIT? My approach is starting with small (like 4MB) and increasing io_tbl by chunk such as 4MB. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
