On Mon, Aug 29, 2022 at 11:40:24AM +0800, Baolu Lu wrote: > On 2022/8/26 22:52, Jason Gunthorpe wrote: > > On Fri, Aug 26, 2022 at 08:11:31PM +0800, Lu Baolu wrote: > > > Allocate the blocking domain when probing devices if the driver supports > > > blocking domain allocation. Otherwise, revert to the previous behavior, > > > that is, use UNMANAGED domain instead when the blocking domain is needed. > > > > > > Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx> > > > Tested-by: Zhangfei Gao<zhangfei.gao@xxxxxxxxxx> > > > Tested-by: Tony Zhu<tony.zhu@xxxxxxxxx> > > > --- > > > drivers/iommu/iommu.c | 29 +++++++++++++++++------------ > > > 1 file changed, 17 insertions(+), 12 deletions(-) > > This seems like a lot of overhead to allocate these things for every > > group? > > > > Why not add a simple refcount on the blocking domain instead and > > allocate the domain on the pasid attach like we do for ownership? > > I am working towards implementing static instance of blocking domain for > each IOMMU driver, and then, there's no much overhead to allocate it in > the probing device path. Well, I thought about that and I don't think we can get there in a short order. Would rather you progress this series without getting entangled in such a big adventure Jason
