Messages in this thread | | | Subject | Re: [debug patch] printk: Add a printk killswitch to robustify NMI watchdog messages | From | Peter Zijlstra <> | Date | Wed, 08 Jun 2011 23:49:18 +0200 |
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On Wed, 2011-06-08 at 22:52 +0200, Ingo Molnar wrote: > Hm, i thought it would be possible to only express it via the > slowpath: if mutex_trylock() succeeds then *all* execution goes into > the slowpath so we don't have to take all the fastpaths into account.
Right, but you first have to take wait_lock, then do the trylock, but that's complicated for asm/mutex-null.h because trylock will then also try to obtain the wait_lock.
You can do it by creating ___mutex_trylock_slowpath() which contains the meat of __mutex_trylock_slowpath() and then implement atomic_mutex_trylock{_irq,_irqsave,} using that, not releasing wait_lock on success.
Shouldn't be too bad, but it ain't too pretty either.
Furthermore, like I said in my initial patch, I share Thomas' worry about 'creative' usage of these primitives.
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