Messages in this thread | | | From | Linus Torvalds <> | Date | Mon, 1 Nov 2021 14:01:13 -0700 | Subject | Re: [GIT pull] sched/core for v5.16-rc1 |
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On Sun, Oct 31, 2021 at 6:16 PM Thomas Gleixner <tglx@linutronix.de> wrote: > > - Make wchan() more robust and work with all kind of unwinders by > enforcing that the task stays blocked while unwinding is in progress.
Ugh. This not-very-important data is protected by a rather core lock.
Is this yet another example of "unwinding is so fragile that it can screw up unless we take a lock that is seriously overkill for a not very important operation"?
Unwinders that need locks because they can do bad things if they are working on unstable data are EVIL and WRONG.
I guess I don't care too much about the pi_lock, and the actual unwinding is hopefully done on tasks that don't care about it, but this smells suspicious to me.
Why is that "stable wchan" so magically important?
Linus
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