On Fri 2009-12-04 12:26:00, Xiaotian Feng wrote: > commit 8bd108d adds preemption point after each opcode parse, then > a sleeping function called from invalid context bug was founded > during suspend/resume stage. this was fixed in commit abe1dfa by > don't cond_resched when irq_disabled. But recent commit 138d156 changes > the behaviour to don't cond_resched when in_atomic. This makes the > sleeping function called from invalid context bug happen again, which > is reported in http://lkml.org/lkml/2009/12/1/371. > > The fix is to cond_sched() only when preemptible, which means not in > irq_disabled or in_atomic. > > @@ -152,7 +152,7 @@ static inline void *acpi_os_acquire_object(acpi_cache_t * cache) > #include <linux/hardirq.h> > #define ACPI_PREEMPTION_POINT() \ > do { \ > - if (!in_atomic_preempt_off()) \ > + if (preemptible()) \ > cond_resched(); \ > } while (0) Note that this is ugly as hell. It means we have two acpi interpretters in kernel, one for preemptible, one for non-preemptible, with very different behaviour. It would be slightly nicer to pass the "preemptible" info explicitely, as function parameters. It would be even better not to need that difference. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
