Re: [PATCH tip/core/rcu 0/6] rcu: fix synchronize_rcu_expedited(), update docs, improve perf

[Ingo Molnar <mingo@elte.hu>]

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

> This patchset contains a bug fix, a performance improvement, and 
> documentation updates:
> 
> o	Update Documentation/RCU/trace.txt to reflect recent changes
> 	(including the removal of rcupreempt.c).

i've applied this to the .33 queue.

> 
> o	Fix to the severe performance problem with excessive IPIs and
> 	lock contention in presence of very large (but legal) numbers
> 	of RCU callbacks (reported by Nick Piggin).

i've applied this to the .32 queue.

> o	Stopgap fix for a bug in TREE_PREEMPT_RCU's implementation of
> 	synchronize_rcu_expedited().  This fix is correct, but no faster
> 	than synchronize_rcu().
> 
> o	Add exports for the updated synchronize_rcu_expedited()
> 	implementation, which moved from a static inline in
> 	include/linux/rcupdate.h to a separately compiled function
> 	in kernel/rcutree_plugin.h.

i've merged these two into the same commit and applied it to the .32 
queue.

> o	Add the new rnp->blocked_tasks field to the rcuhier trace file
> 	in debugfs.
> 
> o	Update the Documentation/RCU/trace.txt documentation to include
> 	the rnp->blocked_tasks tracing.

i've applied these to the .33 queue as well. (both tracing and 
documentation is not urgent material.) I also did minor edits to the 
changelogs.

Thanks Paul!

	Ingo