On Mon, Jan 21, 2019 at 09:42:15AM -0800, Davidlohr Bueso wrote: > Taking a sleeping lock to _only_ increment a variable is quite the > overkill, and pretty much all users do this. Furthermore, some drivers > (ie: infiniband and scif) that need pinned semantics can go to quite > some trouble to actually delay via workqueue (un)accounting for pinned > pages when not possible to acquire it. > > By making the counter atomic we no longer need to hold the mmap_sem > and can simply some code around it for pinned_vm users. The counter > is 64-bit such that we need not worry about overflows such as rdma > user input controlled from userspace. I see a number of MM people Reviewed-by this so are we good to take this in the RDMA tree now? Regards, Jason
