Messages in this thread | | | From | Linus Torvalds <> | Date | Tue, 28 Jul 2020 11:17:02 -0700 | Subject | Re: [RFC][PATCH] exec: Freeze the other threads during a multi-threaded exec |
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On Tue, Jul 28, 2020 at 6:23 AM Eric W. Biederman <ebiederm@xmission.com> wrote: > > For exec all I care about are user space threads. So it appears the > freezer infrastructure adds very little.
Yeah. 99% of the freezer stuff is for just adding the magic notations for kernel threads, and for any user space threads it seems the wrong interface.
> Now to see if I can find another way to divert a task into a slow path > as it wakes up, so I don't need to manually wrap all of the sleeping > calls. Something that plays nice with the scheduler.
The thing is, how many places really care?
Because I think there are like five of them. And they are all marked by taking cred_guard_mutex, or the file table lock.
So it seems really excessive to then create some whole new "let's serialize every thread", when you actually don't care about any of it, except for a couple of very very special cases.
If you care about "thread count stable", you care about exit() and clone(). You don't care about threads that are happily running - or sleeping - doing their own thing.
So trying to catch those threads and freezing them really feels like entirely the wrong interface.
Linus
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