Messages in this thread |  | | From | Linus Torvalds <> | Date | Fri, 30 Sep 2016 21:22:08 -0700 | Subject | Re: [PATCH 1/3] proc: Stop reporting eip and esp in /proc/PID/stat |
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On Fri, Sep 30, 2016 at 7:01 PM, Andy Lutomirski <luto@amacapital.net> wrote: > > Peter, how nasty would it be to add some lightish-weight lock that > lets us pin a task in a non-running state? Maybe we could take the rq > lock, do something to the task to make it sleepy (steal it off the > queue?), unlock the lock, do whatever we're going, then take the lock > again and put it back.
No. Don't do this. Forcing some sleeping lock in the core task state /proc stuff is a nightmare. That thing ends up being used very heavily under some loads. No _way_ is it ok to synchronize with the target task.
> Or if we had a seqlock-like thing, we could maybe arrange for > get_wchan to abort if the task get scheduled between when it starts > and when it finishes.
seq_lock might be ok, but do we even need it? What's the worst that can happen? An odd symbol name showing up in a race condition? Sounds like a non-issue to me.
Linus
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