]> git.karo-electronics.de Git - linux-beck.git/commit
rcu: Enable fourth level of TREE_RCU hierarchy
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Wed, 2 Dec 2009 20:10:14 +0000 (12:10 -0800)
committerIngo Molnar <mingo@elte.hu>
Thu, 3 Dec 2009 10:34:53 +0000 (11:34 +0100)
commitcf244dc01bf68e1ad338b82447f8686d24ea4435
treedc2aebb60ef1eddf92d7e23b72ec2f6c08797684
parentd3f6bad3911736e44ba11f3f3f6ac4e8c837fdfc
rcu: Enable fourth level of TREE_RCU hierarchy

Enable a fourth level of rcu_node hierarchy for TREE_RCU and
TREE_PREEMPT_RCU.  This is for stress-testing and experiemental
purposes only, although in theory this would enable 16,777,216
CPUs on 64-bit systems, though only 1,048,576 CPUs on 32-bit
systems. Normal experimental use of this fourth level will
normally set CONFIG_RCU_FANOUT=2, requiring a 16-CPU system,
though the more adventurous (and more fortunate) experimenters
may wish to chose CONFIG_RCU_FANOUT=3 for 81-CPU systems or even
CONFIG_RCU_FANOUT=4 for 256-CPU systems.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12597846161257-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/rcutree.c
kernel/rcutree.h