On Thu, May 07, 2015 at 12:50:53PM +0200, David Hildenbrand wrote: > Just to make sure we have a common understanding (as written in my cover > letter): > > Your suggestion won't work with !CONFIG_PREEMPT (!CONFIG_PREEMPT_COUNT). If > there is no preempt counter, in_atomic() won't work. But there is, we _always_ have a preempt_count, and irq_enter() et al. _always_ increment the relevant bits. The thread_info::preempt_count field it never under PREEMPT_COUNT include/asm-generic/preempt.h provides stuff regardless of PREEMPT_COUNT. See how __irq_enter() -> preempt_count_add(HARDIRQ_OFFSET) -> __preempt_count_add() _always_ just works. Its only things like preempt_disable() / preempt_enable() that get munged depending on PREEMPT_COUNT/PREEMPT. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>