Commit 1de6e56d authored Sep 29, 2015 by Paul E. McKenney

rcu: Clarify role of ->expmaskinitnext



Analogy with the ->qsmaskinitnext field might lead one to believe that
->expmaskinitnext tracks online CPUs.  This belief is incorrect: Any CPU
that has ever been online will have its bit set in the ->expmaskinitnext
field.  This commit therefore adds a comment to make this clear, at
least to people who read comments.

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

parent 06f60de1

kernel/rcu/tree.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -178,6 +178,8 @@ struct rcu_node {
		/* beginning of each expedited GP. */
		unsigned long expmaskinitnext;
		/* Online CPUs for next expedited GP. */
		/* Any CPU that has ever been online will */
		/* have its bit set. */
		unsigned long grpmask; /* Mask to apply to parent qsmask. */
		/* Only one bit will be set in this mask. */
		int grplo; /* lowest-numbered CPU or group here. */