Messages in this thread | | | From | Andy Lutomirski <> | Date | Fri, 1 Oct 2021 12:02:19 -0700 | Subject | Re: [patch 4/5] sched: Delay task stack freeing on RT |
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On Fri, Oct 1, 2021 at 11:48 AM Andy Lutomirski <luto@kernel.org> wrote: > > On Fri, Oct 1, 2021 at 10:24 AM Thomas Gleixner <tglx@linutronix.de> wrote: > >
> ISTM it would be conceptually for do_exit() to handle its own freeing > in its own preemptible context. Obviously that can't really work, > since we can't free a task_struct or a task stack while we're running > on it. But I wonder if we could approximate it by putting this work > in a workqueue so that it all runs in a normal schedulable context. > To make the shell script case work nicely, we want to release the task > stack before notifying anyone waiting for the dying task to exit, but > maybe that's doable. It could involve some nasty exit_signal hackery, > though.
I'm making this way more complicated than it needs to be. How about we unaccount the task stack in do_exit and release it for real in finish_task_switch()? Other than accounting, free_thread_stack doesn't take any locks.
--Andy
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