Commit 3b6e1dd4 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcutorture: Allow rcutorture without RCU Tasks 



Currently, a CONFIG_PREEMPT_NONE=y kernel substitutes normal RCU for
RCU Tasks.  Unless that kernel builds rcutorture, whether built-in or as
a module, in which case RCU Tasks is (unnecessarily) used.  This both
increases kernel size and increases the complexity of certain tracing
operations.  This commit therefore decouples the presence of rcutorture
from the presence of RCU Tasks.

However, there is a need to select CONFIG_TASKS_RCU for testing purposes.
Except that casual users must not be bothered with questions -- for them,
this needs to be fully automated.  There is thus a CONFIG_FORCE_TASKS_RCU
that selects CONFIG_TASKS_RCU, is user-selectable, but which depends
on CONFIG_RCU_EXPERT.

[ paulmck: Apply kernel test robot feedback. ]

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 40c1278a

kernel/rcu/Kconfig

+13 −5
Original line number Diff line number Diff line
@@ -77,13 +77,21 @@ config TASKS_RCU_GENERIC 
	  This option enables generic infrastructure code supporting

	  task-based RCU implementations.  Not for manual selection.



config FORCE_TASKS_RCU

	bool "Force selection of TASKS_RCU"

	depends on RCU_EXPERT

	select TASKS_RCU

	default n

	help

	  This option force-enables a task-based RCU implementation

	  that uses only voluntary context switch (not preemption!),

	  idle, and user-mode execution as quiescent states.  Not for

	  manual selection in most cases.



config TASKS_RCU

	def_bool 0

	bool

	default n

	select IRQ_WORK

	help

	  This option enables a task-based RCU implementation that uses

	  only voluntary context switch (not preemption!), idle, and

	  user-mode execution as quiescent states.  Not for manual selection.



config TASKS_RUDE_RCU

	def_bool 0

kernel/rcu/Kconfig.debug

+0 −1
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ config RCU_TORTURE_TEST 
	depends on DEBUG_KERNEL

	select TORTURE_TEST

	select SRCU

	select TASKS_RCU

	select TASKS_RUDE_RCU

	default n

	help

kernel/rcu/rcutorture.c

+12 −1
Original line number Diff line number Diff line
@@ -779,6 +779,8 @@ static struct rcu_torture_ops trivial_ops = { 
	.name		= "trivial"

};



#ifdef CONFIG_TASKS_RCU



/*

 * Definitions for RCU-tasks torture testing.

 */
@@ -822,6 +824,15 @@ static struct rcu_torture_ops tasks_ops = { 
	.name		= "tasks"

};



#define TASKS_OPS &tasks_ops,



#else // #ifdef CONFIG_TASKS_RCU



#define TASKS_OPS



#endif // #else #ifdef CONFIG_TASKS_RCU





/*

 * Definitions for rude RCU-tasks torture testing.

 */
@@ -3108,7 +3119,7 @@ rcu_torture_init(void) 
	unsigned long gp_seq = 0;

	static struct rcu_torture_ops *torture_ops[] = {

		&rcu_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, &busted_srcud_ops,

		&tasks_ops, &tasks_rude_ops, TASKS_TRACING_OPS

		TASKS_OPS &tasks_rude_ops, TASKS_TRACING_OPS

		&trivial_ops,

	};

tools/testing/selftests/rcutorture/configs/rcu/TASKS01

+1 −0
Original line number Diff line number Diff line
@@ -7,4 +7,5 @@ CONFIG_PREEMPT=y 
CONFIG_DEBUG_LOCK_ALLOC=y

CONFIG_PROVE_LOCKING=y

#CHECK#CONFIG_PROVE_RCU=y

CONFIG_TASKS_RCU=y

CONFIG_RCU_EXPERT=y

tools/testing/selftests/rcutorture/configs/rcu/TASKS02

+3 −0
Original line number Diff line number Diff line
@@ -2,3 +2,6 @@ CONFIG_SMP=n 
CONFIG_PREEMPT_NONE=y

CONFIG_PREEMPT_VOLUNTARY=n

CONFIG_PREEMPT=n

#CHECK#CONFIG_TASKS_RCU=y

CONFIG_FORCE_TASKS_RCU=y

CONFIG_RCU_EXPERT=y