Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 8 Apr 2022 15:00:43 -1000 | Subject | Re: [RFC][PATCH] timers: Add del_time_free() to be called before freeing timers |
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On Fri, Apr 8, 2022 at 2:49 PM Steven Rostedt <rostedt@goodmis.org> wrote: > > Hmm, well, I'm not sure it would work for all architectures, but what > about the MSB? Setting it to zero on "shutdown"?
Let's just clear the whole thing for now. We don't actually _have_ any timer_restart() cases yet.
I was more thinking that we might have situations where "I don't want to race with timers, but I also don't want to take an interrupt-safe lock" makes a lot of sense.
Most people most definitely are just about "module unload" and similar issues, where it goes along with doing "task_work_cancel()" and friends.
I do wonder if we want some way to shut down new timers that doesn't actually wait for old ones to finish.
We've had issues with some code not being able to use del_timer_sync() simply because they hold locks that could deadlock with any "wait for running timer" situation.
Those places couldn't use a synchronous cancel operation either, for the same reason.
I'm not sure a "make sure no future timers can start" operation is sensible on its own, though. I can't think of a situation where that wouldn't also need that "wait for existing ones to finish".
Linus
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