On Wed, Nov 25, 2020 at 12:07:09PM +0100, Peter Zijlstra wrote: > On Tue, Nov 17, 2020 at 06:19:52PM -0500, Joel Fernandes (Google) wrote: > > Also, for the per-task cookie, it will get weird if we use pointers of any > > emphemeral objects. For this reason, introduce a refcounted object who's > > sole > > purpose is to assign unique cookie value by way of the object's pointer. > > Might be useful to explain why exactly none of the many pid_t's are > good enough.
I thought about this already and it does not seem a good fit. When 2 processes share, it is possible that more processes are added to that logical group. Then the original processes that share die, but if we hold on to the pid_t or task_struct, that would be awkward. It seemed introducing a new refcounted struct was the right way to go. I can add these details to the change log. thanks! - Joel