srcu: Introduce CLASSIC_SRCU Kconfig option

The TREE_SRCU rewrite is large and a bit on the non-simple side, so
this commit helps reduce risk by allowing the old v4.11 SRCU algorithm
to be selected using a new CLASSIC_SRCU Kconfig option that depends
on RCU_EXPERT.  The default is to use the new TREE_SRCU and TINY_SRCU
algorithms, in order to help get these the testing that they need.
However, if your users do not require the update-side scalability that
is to be provided by TREE_SRCU, select RCU_EXPERT and then CLASSIC_SRCU
to revert back to the old classic SRCU algorithm.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2017-03-25 17:23:44 -07:00
parent 32071141b2
commit dad81a2026
7 changed files with 934 additions and 155 deletions

View file

@ -60,6 +60,8 @@ int init_srcu_struct(struct srcu_struct *sp);
#include <linux/srcutiny.h>
#elif defined(CONFIG_TREE_SRCU)
#include <linux/srcutree.h>
#elif defined(CONFIG_CLASSIC_SRCU)
#include <linux/srcuclassic.h>
#else
#error "Unknown SRCU implementation specified to kernel configuration"
#endif