From: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Date: Wed, 14 Apr 2010 23:48:11 +0000 (-0700)
Subject: rcu: permit discontiguous cpu_possible_mask CPU numbering
X-Git-Tag: v2.6.35-rc1~524^2~8
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4a90a0681cf6cd21cd444184302aa045156486b3;p=pandora-kernel.git

rcu: permit discontiguous cpu_possible_mask CPU numbering

TREE_RCU assumes that CPU numbering is contiguous, but some users need
large holes in the numbering to better map to hardware layout.  This patch
makes TREE_RCU (and TREE_PREEMPT_RCU) tolerate large holes in the CPU
numbering.  However, NR_CPUS must still be greater than the largest
CPU number.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index f391886be8f0..c60fd74e7ec9 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -1913,7 +1913,7 @@ static void __init rcu_init_one(struct rcu_state *rsp)
 
 	rnp = rsp->level[NUM_RCU_LVLS - 1];
 	for_each_possible_cpu(i) {
-		if (i > rnp->grphi)
+		while (i > rnp->grphi)
 			rnp++;
 		rsp->rda[i]->mynode = rnp;
 		rcu_boot_init_percpu_data(i, rsp);