| Date | Wed, 25 Nov 2020 12:10:14 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH -tip 22/32] sched: Split the cookie and setup per-task cookie on fork |
| |
On Tue, Nov 17, 2020 at 06:19:52PM -0500, Joel Fernandes (Google) wrote: > +void sched_core_tag_requeue(struct task_struct *p, unsigned long cookie, bool group) > +{ > + if (!p) > + return; > + > + if (group) > + p->core_group_cookie = cookie; > + else > + p->core_task_cookie = cookie; > + > + /* Use up half of the cookie's bits for task cookie and remaining for group cookie. */ > + p->core_cookie = (p->core_task_cookie << > + (sizeof(unsigned long) * 4)) + p->core_group_cookie;
This seems dangerous; afaict there is nothing that prevents cookie collision.
|