Messages in this thread | | | Date | Mon, 6 Feb 2006 23:07:50 +0000 | From | Russell King <> | Subject | Re: [patch 05/44] generic {,test_and_}{set,clear,change}_bit() |
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On Fri, Feb 03, 2006 at 10:55:36AM +0100, Martin Waitz wrote: > On Wed, Feb 01, 2006 at 06:02:29PM +0900, Akinobu Mita wrote: > > +static __inline__ void set_bit(int nr, volatile unsigned long *addr) > > +{ > > + unsigned long mask = BITOP_MASK(nr); > > + unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr); > > + unsigned long flags; > > + > > + _atomic_spin_lock_irqsave(p, flags); > > + *p |= mask; > > + _atomic_spin_unlock_irqrestore(p, flags); > > +} > > You could even use your new generic non-atomic bitops to implement these
Depends - to do so would increase the amount of code within the locked region, which raises the probability of contention since the locked time becomes longer.
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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