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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-04-21 09:12:13 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-05-27 12:59:05 -0700
commit47d631af58bb9b2f2dd3d0da8c98a79a5e75c738 (patch)
tree7472330c70684ac02140d2f3796b042b53a4f6dd /kernel/rcu/tree.h
parent05c5df31afd1092ca6322094d22aff6351fa67fe (diff)
downloadlinux-sh-47d631af58bb9b2f2dd3d0da8c98a79a5e75c738.tar.gz
rcu: Make RCU able to tolerate undefined CONFIG_RCU_FANOUT_LEAF
This commit introduces an RCU_FANOUT_LEAF C-preprocessor macro so that RCU will build even when CONFIG_RCU_FANOUT_LEAF is undefined. The RCU_FANOUT_LEAF macro is set to the value of CONFIG_RCU_FANOUT_LEAF when defined, otherwise it is set to 32 for 32-bit systems and 64 for 64-bit systems. This commit then makes CONFIG_RCU_FANOUT_LEAF depend on CONFIG_RCU_EXPERT, so that Kconfig users won't be asked about CONFIG_RCU_FANOUT_LEAF unless they want to be. Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
Diffstat (limited to 'kernel/rcu/tree.h')
-rw-r--r--kernel/rcu/tree.h12
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index ac3020fff028..7d949c186302 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -48,7 +48,17 @@
# endif
#endif /* #else #ifdef CONFIG_RCU_FANOUT */
-#define RCU_FANOUT_1 (CONFIG_RCU_FANOUT_LEAF)
+#ifdef CONFIG_RCU_FANOUT_LEAF
+#define RCU_FANOUT_LEAF CONFIG_RCU_FANOUT_LEAF
+#else /* #ifdef CONFIG_RCU_FANOUT_LEAF */
+# ifdef CONFIG_64BIT
+# define RCU_FANOUT_LEAF 64
+# else
+# define RCU_FANOUT_LEAF 32
+# endif
+#endif /* #else #ifdef CONFIG_RCU_FANOUT_LEAF */
+
+#define RCU_FANOUT_1 (RCU_FANOUT_LEAF)
#define RCU_FANOUT_2 (RCU_FANOUT_1 * RCU_FANOUT)
#define RCU_FANOUT_3 (RCU_FANOUT_2 * RCU_FANOUT)
#define RCU_FANOUT_4 (RCU_FANOUT_3 * RCU_FANOUT)