On Thu, Nov 03, 2016 at 05:33:27PM +0100, Sebastian Andrzej Siewior wrote: > On 2016-11-03 09:22:28 [-0700], Paul E. McKenney wrote: > > On Wed, Nov 02, 2016 at 05:30:02PM +0100, Sebastian Andrzej Siewior wrote: > > > RCU_EXPEDITE_BOOT should speed up the boot process by enforcing > > > synchronize_rcu_expedited() instead of synchronize_rcu() during the boot > > > process. There should be no reason why one does not want this and there > > > is no need worry about real time latency at this point. > > > Therefore make it default. > > > > > > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> > > > > Well, it has been awhile since I removed a Kconfig parameter. > > > > So why could this be a bad thing? > > > > 1. Very large systems might see scalability issues with unconditional > > expediting at boot. But if we don't try it, we won't know. > > You mean we would make the boot process slower for them instead of > faster? For really bit systems, quite possibly, where "really big" means many hundreds or (more likely) thousands of CPUs. But there are things that I can do to fix this when and if. > > 2. People bringing up new hardware might not want quite so many > > IPIs. But they can just set rcu_normal to prevent that. > > I wanted to make things simple and not complicated… I know that feeling. ;-) > > I am therefore queuing it for testiong and review. ;-) > > Okay thanks. Thanx, Paul > Sebastian > -- 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
