On 06/25/2014 07:20 PM, David Laight wrote: > From: Wei Yang >> On Wed, Jun 25, 2014 at 02:12:34PM +1000, Alexey Kardashevskiy wrote: >>> On 06/25/2014 11:12 AM, Wei Yang wrote: >>>> On Tue, Jun 24, 2014 at 08:06:32PM +1000, Alexey Kardashevskiy wrote: >>>>> On 06/10/2014 11:56 AM, Wei Yang wrote: >>>>>> Current iommu_table of a PE is a static field. This will have a problem when >>>>>> iommu_free_table is called. >>>>> >>>>> What kind of problem? This table is per PE and PE is not going anywhere. >>>>> >>>> >>>> Yes, for Bus PE, they will always sit in the system. When VF PE introduced, >>>> they could be released on the fly. When they are released, so do the iommu >>>> table for the PE. >>> >>> iommu_table is a part of PE struct. When PE is released, iommu_table will >>> go with it as well. Why to make is a pointer? I would understand it if you >>> added reference counting there but no - iommu_table's lifetime is equal to >>> PE lifetime. >>> >> >> Yes, iommu_talbe's life time equals to PE lifetime, so when releasing a PE we >> need to release the iommu table. Currently, there is one function to release >> the iommu table, iommu_free_table() which takes a pointer of the iommu_table >> and release it. >> >> If the iommu table in PE is just a part of PE, it will have some problem to >> release it with iommu_free_table(). That's why I make it a pointer in PE >> structure. > > What are the sizes of the iommu table and the PE structure? This is all about iommu_table struct (which is just a descriptor), not IOMMU table per se (which may be megabytes) :) > If the table is a round number of pages then you probably don't want to > embed it inside the PE structure. -- Alexey -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
