Re: [PATCH tip/core/rcu 0/7] RCU_FAST_NO_HZ changes for 3.6

[Ingo Molnar <mingo@kernel.org>]

* Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:

> Hello!
> 
> This patch series provides more adjustments to the (relatively) new
> large-system-safe implementation for RCU_FAST_NO_HZ:
> 
> 1.	Remove RCU_FAST_NO_HZ dependency on stop_machine() nature of
> 	CPU hotplug.
> 2.	Make RCU_FAST_NO_HZ tracing distinguish between short and
> 	long idle intervals.
> 3.	Move RCU_FAST_NO_HZ per-CPU state variables to the rcu_dynticks
> 	per-CPU structure.
> 4.	Precompute RCU_FAST_NO_HZ timer offsets so that the timers
> 	will actually be paid attention to.  This fixes the slow-boot
> 	problem that hit a few people.
> 5.	Convert ftrace_dump() calls in idle entry and idle exit from
> 	DUMP_ALL to DUMP_ORIG.
> 6.	Fix erroneous TINY_PREEMPT_RCU assumption that rcu_preempt_needs_cpu()
> 	is a quiescent state (it is not).
> 7.	Round RCU_FAST_NO_HZ lazy timeout to nearest second to conserve
> 	power on systems with synchronized scheduler-clock interrupts.
> 
> I am considering pushing #1-#4 into 3.5 for the slow-boot regression.
> If you object, please let me know.

Sure, that's sensible - could get this to me ASAP so that we can 
send it to Linus before -rc2? #3 and #4 are pretty large so we 
want them upstream ASAP.

Thanks,

	Ingo