Commit b3e627d3 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Paul E. McKenney
Browse files

rcu: Make PREEMPT_RCU be a modifier to TREE_RCU 



Currently PREEMPT_RCU and TREE_RCU are mutually exclusive Kconfig
options.  But PREEMPT_RCU actually specifies a kind of TREE_RCU,
namely a preemptible TREE_RCU. This commit therefore makes PREEMPT_RCU
be a modifer to the TREE_RCU Kconfig option.  This has the benefit of
simplifying several of the #if expressions that formerly needed to
check both, but now need only check one or the other.

Signed-off-by: default avatarLai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: default avatarLai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: default avatarJoel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 03bd2983

include/linux/rcupdate.h

+2 −2
Original line number Original line Diff line number Diff line
@@ -167,7 +167,7 @@ do { \ 
 * TREE_RCU and rcu_barrier_() primitives in TINY_RCU.

 * TREE_RCU and rcu_barrier_() primitives in TINY_RCU.

 */

 */





#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)

#if defined(CONFIG_TREE_RCU)

#include <linux/rcutree.h>

#include <linux/rcutree.h>

#elif defined(CONFIG_TINY_RCU)

#elif defined(CONFIG_TINY_RCU)

#include <linux/rcutiny.h>

#include <linux/rcutiny.h>
@@ -601,7 +601,7 @@ do { \ 
 * read-side critical section that would block in a !PREEMPT kernel.

 * read-side critical section that would block in a !PREEMPT kernel.

 * But if you want the full story, read on!

 * But if you want the full story, read on!

 *

 *

 * In non-preemptible RCU implementations (TREE_RCU and TINY_RCU),

 * In non-preemptible RCU implementations (pure TREE_RCU and TINY_RCU),

 * it is illegal to block while in an RCU read-side critical section.

 * it is illegal to block while in an RCU read-side critical section.

 * In preemptible RCU implementations (PREEMPT_RCU) in CONFIG_PREEMPTION

 * In preemptible RCU implementations (PREEMPT_RCU) in CONFIG_PREEMPTION

 * kernel builds, RCU read-side critical sections may be preempted,

 * kernel builds, RCU read-side critical sections may be preempted,

include/trace/events/rcu.h

+2 −2
Original line number Original line Diff line number Diff line
@@ -41,7 +41,7 @@ TRACE_EVENT(rcu_utilization, 
	TP_printk("%s", __entry->s)

	TP_printk("%s", __entry->s)

);

);





#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)

#if defined(CONFIG_TREE_RCU)





/*

/*

 * Tracepoint for grace-period events.  Takes a string identifying the

 * Tracepoint for grace-period events.  Takes a string identifying the
@@ -432,7 +432,7 @@ TRACE_EVENT_RCU(rcu_fqs, 
		  __entry->cpu, __entry->qsevent)

		  __entry->cpu, __entry->qsevent)

);

);





#endif /* #if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU) */

#endif /* #if defined(CONFIG_TREE_RCU) */





/*

/*

 * Tracepoint for dyntick-idle entry/exit events.  These take a string

 * Tracepoint for dyntick-idle entry/exit events.  These take a string

kernel/rcu/Kconfig

+7 −6
Original line number Original line Diff line number Diff line
@@ -7,7 +7,7 @@ menu "RCU Subsystem" 




config TREE_RCU

config TREE_RCU

	bool

	bool

	default y if !PREEMPTION && SMP

	default y if SMP

	help

	help

	  This option selects the RCU implementation that is

	  This option selects the RCU implementation that is

	  designed for very large SMP system with hundreds or

	  designed for very large SMP system with hundreds or
@@ -17,6 +17,7 @@ config TREE_RCU 
config PREEMPT_RCU

config PREEMPT_RCU

	bool

	bool

	default y if PREEMPTION

	default y if PREEMPTION

	select TREE_RCU

	help

	help

	  This option selects the RCU implementation that is

	  This option selects the RCU implementation that is

	  designed for very large SMP systems with hundreds or

	  designed for very large SMP systems with hundreds or
@@ -78,7 +79,7 @@ config TASKS_RCU 
	  user-mode execution as quiescent states.

	  user-mode execution as quiescent states.





config RCU_STALL_COMMON

config RCU_STALL_COMMON

	def_bool ( TREE_RCU || PREEMPT_RCU )

	def_bool TREE_RCU

	help

	help

	  This option enables RCU CPU stall code that is common between

	  This option enables RCU CPU stall code that is common between

	  the TINY and TREE variants of RCU.  The purpose is to allow

	  the TINY and TREE variants of RCU.  The purpose is to allow
@@ -86,13 +87,13 @@ config RCU_STALL_COMMON 
	  making these warnings mandatory for the tree variants.

	  making these warnings mandatory for the tree variants.





config RCU_NEED_SEGCBLIST

config RCU_NEED_SEGCBLIST

	def_bool ( TREE_RCU || PREEMPT_RCU || TREE_SRCU )

	def_bool ( TREE_RCU || TREE_SRCU )





config RCU_FANOUT

config RCU_FANOUT

	int "Tree-based hierarchical RCU fanout value"

	int "Tree-based hierarchical RCU fanout value"

	range 2 64 if 64BIT

	range 2 64 if 64BIT

	range 2 32 if !64BIT

	range 2 32 if !64BIT

	depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT

	depends on TREE_RCU && RCU_EXPERT

	default 64 if 64BIT

	default 64 if 64BIT

	default 32 if !64BIT

	default 32 if !64BIT

	help

	help
@@ -112,7 +113,7 @@ config RCU_FANOUT_LEAF 
	int "Tree-based hierarchical RCU leaf-level fanout value"

	int "Tree-based hierarchical RCU leaf-level fanout value"

	range 2 64 if 64BIT

	range 2 64 if 64BIT

	range 2 32 if !64BIT

	range 2 32 if !64BIT

	depends on (TREE_RCU || PREEMPT_RCU) && RCU_EXPERT

	depends on TREE_RCU && RCU_EXPERT

	default 16

	default 16

	help

	help

	  This option controls the leaf-level fanout of hierarchical

	  This option controls the leaf-level fanout of hierarchical
@@ -187,7 +188,7 @@ config RCU_BOOST_DELAY 




config RCU_NOCB_CPU

config RCU_NOCB_CPU

	bool "Offload RCU callback processing from boot-selected CPUs"

	bool "Offload RCU callback processing from boot-selected CPUs"

	depends on TREE_RCU || PREEMPT_RCU

	depends on TREE_RCU

	depends on RCU_EXPERT || NO_HZ_FULL

	depends on RCU_EXPERT || NO_HZ_FULL

	default n

	default n

	help

	help

kernel/rcu/Makefile

+0 −1
Original line number Original line Diff line number Diff line
@@ -9,6 +9,5 @@ obj-$(CONFIG_TINY_SRCU) += srcutiny.o 
obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o

obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o

obj-$(CONFIG_RCU_PERF_TEST) += rcuperf.o

obj-$(CONFIG_RCU_PERF_TEST) += rcuperf.o

obj-$(CONFIG_TREE_RCU) += tree.o

obj-$(CONFIG_TREE_RCU) += tree.o

obj-$(CONFIG_PREEMPT_RCU) += tree.o

obj-$(CONFIG_TINY_RCU) += tiny.o

obj-$(CONFIG_TINY_RCU) += tiny.o

obj-$(CONFIG_RCU_NEED_SEGCBLIST) += rcu_segcblist.o
 
obj-$(CONFIG_RCU_NEED_SEGCBLIST) += rcu_segcblist.o

kernel/rcu/rcu.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -454,7 +454,7 @@ enum rcutorture_type { 
	INVALID_RCU_FLAVOR

	INVALID_RCU_FLAVOR

};

};





#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)

#if defined(CONFIG_TREE_RCU)

void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,

void rcutorture_get_gp_data(enum rcutorture_type test_type, int *flags,

			    unsigned long *gp_seq);

			    unsigned long *gp_seq);

void do_trace_rcu_torture_read(const char *rcutorturename,

void do_trace_rcu_torture_read(const char *rcutorturename,