On Tue, 2010-07-27 at 11:41 +0200, Thomas Gleixner wrote: > On Sun, 25 Jul 2010, Mike Galbraith wrote: > > > On Fri, 2010-07-23 at 16:39 +0200, Mike Galbraith wrote: > > > Greetings, > > > > > > Consoles (serial and vt) are going silent after. > > > > > > [ 1.100178] Freeing initrd memory: 9348k freed > > > [ 1.453009] Freeing unused kernel memory: 1000k freed > > > [ 1.464463] Freeing unused kernel memory: 512k freed > > > [ 1.469724] Freeing unused kernel memory: 360k freed > > > > > > If the kernel is configured PREEMPT_VOLUNTARY, consoles work fine again. > > > So far, I've only eyeballed the rt patch, and noticed nothing. I'll be > > > poking around in (shudder) console code soon I suppose, but before I > > > start that.. adventure, is this a known issue? > > > > Hm, that was suspiciously easy. > > > > console: really enable interrupts in release_console_mutex() > > > > vprintk() > > raw_local_irq_save() > > acquire_console_mutex_for_printk() > > release_console_mutex() > > raw_spin_unlock_save() > > raw_spin_unlock_irqrestore() > > call_console_drivers() > > _call_console_drivers() > > __call_console_drivers() > > console_atomic_safe() "nope". > > > > Signed-off-by: Mike Galbraith <efault@xxxxxx> > > > > --- > > kernel/printk.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > Index: tip-rt/kernel/printk.c > > =================================================================== > > --- tip-rt.orig/kernel/printk.c > > +++ tip-rt/kernel/printk.c > > @@ -1072,7 +1072,7 @@ void release_console_mutex(void) > > * with interrupts disabled): > > */ > > #ifdef CONFIG_PREEMPT_RT > > - raw_spin_unlock_irqrestore(&logbuf_lock, flags); > > + raw_spin_unlock_irq(&logbuf_lock); > > Not really a good idea. If printk is called from an irq disabled > region, then we unconditionally enabled interrupts here. The comment > above this is misleading and needs to be removed. We had problems in > that area before. Does the following patch solve your problem as well ? Aha. Yes, it does. -Mike -- 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
