On 12/02/11 15:49, Steven Rostedt wrote: > On Fri, 2011-12-02 at 15:08 -0800, Frank Rowand wrote: >> Hi Steve, >> >> I get a "sleeping function called from invalid context" when I invoke sysrq Z. >> >> I get this both with CONFIG_MAGIC_SYSRQ_FORCE_PRINTK enabled and disabled. > > Patient: Hey doctor, it hurts when I do this > > Doctor: Don't do that. I had similar thoughts as I was writing my email. < snip > > > Oh! looking into the ring_buffer code, could you add this: > (totally untested) > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index 2467714..2ffbb9d 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -1045,7 +1045,7 @@ static inline int ok_to_lock(void) > if (in_nmi()) > return 0; > #ifdef CONFIG_PREEMPT_RT_FULL > - if (in_atomic()) > + if (in_atomic() || irqs_disabled()) > return 0; > #endif > return 1; I would say the result is good with the patch applied. If CONFIG_MAGIC_SYSRQ_FORCE_PRINTK is disabled then the splat does not occur and the ftrace buffer is printed on the console. If CONFIG_MAGIC_SYSRQ_FORCE_PRINTK is enabled, then the splat does not occur and the ftrace buffer sometimes is printed on the console. I think that this is good enough, given that sysrq when CONFIG_PREEMPT_RT_FULL is enabled is somewhat dicey to begin with. -Frank -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
