On Tue, 2010-07-20 at 21:58 -0700, FUJITA Tomonori wrote: > On Tue, 20 Jul 2010 15:14:57 -0700 > Alok Kataria <akataria@xxxxxxxxxx> wrote: > > > Reviving a 4 month old thread. > > I am still waiting for any clues on this question below. > > Basically, you want to add hot-plug memory and enable swiotlb, right? Not really, I am planning to do something like this, @@ -52,7 +52,7 @@ int __init pci_swiotlb_detect(void) /* don't initialize swiotlb if iommu=off (no_iommu=1) */ #ifdef CONFIG_X86_64 - if (!no_iommu && max_pfn > MAX_DMA32_PFN) + if (!no_iommu && (max_pfn > MAX_DMA32_PFN || hotplug_possible())) swiotlb = 1; #endif if (swiotlb_force) BUT, I don't know how that hotplug_possible function will look like or if such an interface already exists in the kernel (my search didn't turn up any) ? IMO, it should be possible to go read the SRAT to see if this system has support for hotplug memory and then enable swiotlb if it does. Sounds right ? Thanks, Alok > > We can't start swiotlb reliably after a system starts. > > See dma32_reserve_boatmen() and dma32_free_bootmem(). What we do is > reserving huge memory in DMA32 zone for swiotlb and releasing it if we > find that we don't need swiotlb. We can't find enough memory for > swiotlb in dma32 after a system starts. -- 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
