On Mon, Apr 29, 2013 at 06:17:40PM +1000, Ian Munsie wrote: > From: Ian Munsie <imunsie@xxxxxxxxxxx> > > If a doorbell IPI comes in while a thread is in nap power saving, the > doorbell interrupt won't be replayed by the hardware since it is edge > sensitive. Currently we are not replaying these interrupts in software, > which can cause threads to miss IPIs that come in during power saving > and eventually will result in an RCU warning from rcu_sched that it has > detected a stalled CPU. > > This patch fixes the issue by testing if a doorbell caused the thread to > come out of power saving and sets the corresponding bit in the paca to > indicate a doorbell happened, which will then be handled by the existing > interrupt replay code. > > This is not an issue with other interrupts that can wake a thread > (external, decrementer) as they are level sensitive and will continue to > be asserted by the hardware. > > Signed-off-by: Ian Munsie <imunsie@xxxxxxxxxxx> <formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. </formletter> -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html