On Wed, 23 Jan 2019 11:33:53 -0700 Jason Gunthorpe <jgg@xxxxxxxx> wrote: > 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? Please do.
