Messages in this thread |  | | | Subject | Re: spinlock which can morph into a mutex | | From | Miquel van Smoorenburg <> | | Date | Fri, 18 Dec 2009 19:19:07 +0100 |
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On Fri, 2009-12-18 at 18:14 +0100, Thomas Gleixner wrote: > On Fri, 18 Dec 2009, Miquel van Smoorenburg wrote: > I think I need a spinlock that can morph into a mutex .. > > Is the writer frequency and the possible contention so high that you > need a spinlock at all ?
Possibly - I don't want to degrade the performance of existing code (which uses a spinlock).
> Test it :)
Good point.
> If the mutex is still to heavy weight for you, then you can solve it > without implementing another weird concurrency control: > > wait_event_(un)interruptible(&hash_wq, !hash_update_active); > > hash_update_active = 1; > .... > hash_update_active = 0; > wake_up(&hash_wq);
Ah, ofcourse. Thanks for pointing that out!
Thanks everybody for your input. I gained quite a bit of insight.
Mike.
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