Commit 8c703d35 authored by Jonathan Corbet's avatar Jonathan Corbet Committed by Linus Torvalds
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in_atomic(): document why it is unsuitable for general use 



Discourage people from inappropriately using in_atomic()

Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f67e74ca

include/linux/hardirq.h

+7 −0
Original line number Diff line number Diff line
@@ -72,6 +72,13 @@ 
#define in_softirq()		(softirq_count())

#define in_interrupt()		(irq_count())



/*

 * Are we running in atomic context?  WARNING: this macro cannot

 * always detect atomic context; in particular, it cannot know about

 * held spinlocks in non-preemptible kernels.  Thus it should not be

 * used in the general case to determine whether sleeping is possible.

 * Do not use in_atomic() in driver code.

 */

#define in_atomic()		((preempt_count() & ~PREEMPT_ACTIVE) != 0)



#ifdef CONFIG_PREEMPT