On Fri, Jan 20, 2023 at 07:28:19PM +0000, Robin Murphy wrote: > Overall I'm starting to wonder if it might not be better to stick a "use > GFP_KERNEL_ACCOUNT if you allocate" flag in the domain for any level of the > API internals to pick up as appropriate, rather than propagate per-call gfp > flags everywhere. I was thinking about this some more, and I don't thinking hiding the GFP_KERNEL_ACCOUNT in the iommu driver will be very maintainable. The GFP_KERNEL_ACCOUNT is sensitive to current since that is where it gets the cgroup from, if we start putting it in driver code directly it becomes very hard to understand if the call chains are actually originating from a syscall or not. I'd prefer we try to keep thing so that iommufd provides the GFP_KERNEL_ACCOUNT on a call-by-call basis where it is clearer what call chains originate from a system call vs not. So, I think we will strive for adding a gfp flag to the future 'alloc domain iommufd' and pass GFP_KERNEL_ACCOUNT there. Then we can see what is left. Jason
