Messages in this thread | | | Date | Fri, 07 Dec 2012 23:03:14 +0530 | From | "Srivatsa S. Bhat" <> | Subject | Re: [RFC PATCH v2 01/10] CPU hotplug: Provide APIs for "light" atomic readers to prevent CPU offline |
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On 12/07/2012 03:32 AM, Steven Rostedt wrote: > On Fri, 2012-12-07 at 01:06 +0530, Srivatsa S. Bhat wrote: >> The root-cause of this deadlock is again lock-ordering mismatch right? >> CPU0 takes locks in order A, B >> CPU1 takes locks in order B, A >> >> And the writer facilitates in actually getting deadlocked. >> >> I avoid this in this patchset by always taking the locks in the same >> order. So we won't be deadlocking like this. > > OK, I haven't looked closely at the patch yet. I'm currently hacking on > my own problems. But just from the description above, it looked like you > were using rw_locks() to be able to inverse the order of the locks. >
Ah, ok, no problem! I'd be grateful if you could take a look when you are free :-) I'll post a v3 soon, which has a completely redesigned synchronization scheme, to address the performance concerns related to global rwlocks that Tejun raised.
Regards, Srivatsa S. Bhat
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