linux/kernel/rcu/Makefile

obj-y += update.o sync.o
obj-$(CONFIG_SRCU) += srcu.o
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
obj-$(CONFIG_TREE_RCU) += tree.o
obj-$(CONFIG_PREEMPT_RCU) += tree.o
obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o
obj-$(CONFIG_TINY_RCU) += tiny.o
rcu: Create rcu_sync infrastructure The rcu_sync infrastructure can be thought of as infrastructure to be used to implement reader-writer primitives having extremely lightweight readers during times when there are no writers. The first use is in the percpu_rwsem used by the VFS subsystem. This infrastructure is functionally equivalent to struct rcu_sync_struct { atomic_t counter; }; /* Check possibility of fast-path read-side operations. / static inline bool rcu_sync_is_idle(struct rcu_sync_struct rss) { return atomic_read(&rss->counter) == 0; } /* Tell readers to use slowpaths. / static inline void rcu_sync_enter(struct rcu_sync_struct rss) { atomic_inc(&rss->counter); synchronize_sched(); } /* Allow readers to once again use fastpaths. / static inline void rcu_sync_exit(struct rcu_sync_struct rss) { synchronize_sched(); atomic_dec(&rss->counter); } The main difference is that it records the state and only calls synchronize_sched() if required. At least some of the calls to synchronize_sched() will be optimized away when rcu_sync_enter() and rcu_sync_exit() are invoked repeatedly in quick succession. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> 2015-08-21 17:42:44 +00:00			`obj-y += update.o sync.o`
rcu: Make SRCU optional by using CONFIG_SRCU SRCU is not necessary to be compiled by default in all cases. For tinification efforts not compiling SRCU unless necessary is desirable. The current patch tries to make compiling SRCU optional by introducing a new Kconfig option CONFIG_SRCU which is selected when any of the components making use of SRCU are selected. If we do not select CONFIG_SRCU, srcu.o will not be compiled at all. text data bss dec hex filename 2007 0 0 2007 7d7 kernel/rcu/srcu.o Size of arch/powerpc/boot/zImage changes from text data bss dec hex filename 831552 64180 23944 919676 e087c arch/powerpc/boot/zImage : before 829504 64180 23952 917636 e0084 arch/powerpc/boot/zImage : after so the savings are about ~2000 bytes. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> CC: Josh Triplett <josh@joshtriplett.org> CC: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [ paulmck: resolve conflict due to removal of arch/ia64/kvm/Kconfig. ] 2014-12-05 16:24:45 +00:00			`obj-$(CONFIG_SRCU) += srcu.o`
rcutorture: Abstract rcu_torture_random() Because rcu_torture_random() will be used by the locking equivalent to rcutorture, pull it out into its own module. This new module cannot be separately configured, instead, use the Kconfig "select" statement from the Kconfig options of tests depending on it. Suggested-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> 2014-01-27 19:49:39 +00:00			`obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o`
rcu: Move RCU-related source code to kernel/rcu directory Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> 2013-10-09 03:23:47 +00:00			`obj-$(CONFIG_TREE_RCU) += tree.o`
rcu: Remove redundant TREE_PREEMPT_RCU config option PREEMPT_RCU and TREE_PREEMPT_RCU serve the same function after TINY_PREEMPT_RCU has been removed. This patch removes TREE_PREEMPT_RCU and uses PREEMPT_RCU config option in its place. Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> 2014-09-22 18:00:48 +00:00			`obj-$(CONFIG_PREEMPT_RCU) += tree.o`
rcu: Move RCU-related source code to kernel/rcu directory Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Ingo Molnar <mingo@kernel.org> 2013-10-09 03:23:47 +00:00			`obj-$(CONFIG_TREE_RCU_TRACE) += tree_trace.o`
			`obj-$(CONFIG_TINY_RCU) += tiny.o`