From: Jonathan Corbet Date: Fri, 28 Mar 2008 21:15:49 +0000 (-0700) Subject: in_atomic(): document why it is unsuitable for general use X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8c703d35fa91911dd92a18c31a718853f483ad80;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git in_atomic(): document why it is unsuitable for general use Discourage people from inappropriately using in_atomic() Signed-off-by: Jonathan Corbet Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 49829988bfa0..897f723bd222 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -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