On Sun, 22 Mar 2009 16:03:31 -0700 "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > On Sun, Mar 22, 2009 at 03:44:33PM -0700, Arjan van de Ven wrote: > > On Sun, 22 Mar 2009 13:52:12 -0700 > > "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > > > > > On Sun, Mar 22, 2009 at 12:46:32PM -0700, Arjan van de Ven wrote: > > > > On Sun, 22 Mar 2009 09:53:24 -0700 > > > > "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > > > > How many synchronize_rcu() calls are you seeing on the > > > > > > > boot path? > > > > > > > > > > > > I see 20 that hit the above code path (eg ones that wait) > > > > > > until userspace starts. > > > > > > > > > > So with well-behaved readers, the full sequence would be worth > > > > > something like 50-60 milliseconds. > > > > > > > > yeah it's about 10% if the total kernel boot time.. so it does > > > > start to matter > > > > > > Half-second boot, eh? That would indeed be impressive. > > > > half a second until calling init.. that's what I have today (with > > all drivers built in).. nothing really special needed for it > > (well a few small patches that are pending for 2.6.30 ;-) > > I thought the measurement was until the desktop was running with no > more disk activity. ;-) yeah that's like 2 seconds after that ;) > > But in any case, I will see what I can do about speeding up > synchronize_rcu(). I will likely start with TREE_RCU, and I may need > some sort of indication that boot is in progress. system_state == SYSTEM_BOOTING is not a very elegant test but it works -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
