Re: 174cc7187e6f ACPICA: Tables: Back port acpi_get_table_with_size() and early_acpi_os_unmap_memory() from Linux kernel

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

On Wed, Jan 11, 2017 at 11:03:23AM +0100, Borislav Petkov wrote:
> On Wed, Jan 11, 2017 at 01:51:56AM -0800, Paul E. McKenney wrote:
> > Yes, you could make RCU expedited grace periods go back to using the
> > requesting task, and that would allow expedited grace periods to run early
> > in the boot process.  But that causes problems with signals and the like
> > unless you revert a few other patches.  The bugzilla is interesting --
> > it looks like ACPI was in some cases doing early-boot grace-period waits
> > some time back?
> 
> I think this and https://bugzilla.suse.com/show_bug.cgi?id=1017783 is an
> example of a bunch of toshiba schlaptops which cause the issue. So it
> looks like ACPI is doing something very early on those which tickles the
> issue to happen.
> 
> But this is ACPI - anything can happen!

;-) ;-) ;-)

> > I have a limping prototype RCU patch that should avoid this problem.
> >
> > If all goes well, I will send it out late tomorrow evening, Pacific Time.
> 
> Attach it to the bugzilla too, pls, because the people there trigger the
> issue.
> 
> I have the respective(?) SUSE bug and I can ask people there to run it
> too.

That would be very good!  Thinking good thoughts for the ongoing tests...

							Thanx, Paul