summaryrefslogtreecommitdiff
path: root/kernel/rcu/tree.h
diff options
context:
space:
mode:
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2018-04-18 11:11:39 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2018-05-15 10:29:18 -0700
commitc91a8675b9cc697c725b6d97fcc7f157f4a989d0 (patch)
tree335a7e265dda2c90ad19b8240b65be694fab0a0e /kernel/rcu/tree.h
parent825a9911f6447299a69edacecc81fa2cdc5290a7 (diff)
rcu: Add accessor macros for the ->need_future_gp[] array
Accessors for the ->need_future_gp[] array are currently open-coded, which makes them difficult to change. To improve maintainability, this commit adds need_future_gp_mask() to compute the indexing mask from the array size, need_future_gp_element() to access the element corresponding to the specified grace-period number, and need_any_future_gp() to determine if any future grace period is needed. This commit also applies need_future_gp_element() to existing open-coded single-element accesses. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Nicholas Piggin <npiggin@gmail.com>
Diffstat (limited to 'kernel/rcu/tree.h')
-rw-r--r--kernel/rcu/tree.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index f491ab4f2e8e..18b091474ffa 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -159,6 +159,21 @@ struct rcu_node {
wait_queue_head_t exp_wq[4];
} ____cacheline_internodealigned_in_smp;
+/* Accessors for ->need_future_gp[] array. */
+#define need_future_gp_mask() \
+ (ARRAY_SIZE(((struct rcu_node *)NULL)->need_future_gp) - 1)
+#define need_future_gp_element(rnp, c) \
+ ((rnp)->need_future_gp[(c) & need_future_gp_mask()])
+#define need_any_future_gp(rnp) \
+({ \
+ int __i; \
+ bool __nonzero = false; \
+ \
+ for (__i = 0; __i < ARRAY_SIZE((rnp)->need_future_gp); __i++) \
+ __nonzero = __nonzero || (rnp)->need_future_gp[__i]; \
+ __nonzero; \
+})
+
/*
* Bitmasks in an rcu_node cover the interval [grplo, grphi] of CPU IDs, and
* are indexed relative to this interval rather than the global CPU ID space.