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Commit f7a10a97 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

rcu: Remove the RCU_KTHREAD_PRIO Kconfig option 



Anything that can be done with the RCU_KTHREAD_PRIO Kconfig option can
also be done with the rcutree.kthread_prio kernel boot parameter.
This commit therefore removes this Kconfig option.

Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
parent 90040c9e

init/Kconfig

+0 −31
Original line number Original line Diff line number Diff line
@@ -697,37 +697,6 @@ config RCU_BOOST 
	  Say Y here if you are working with real-time apps or heavy loads

	  Say Y here if you are working with real-time apps or heavy loads

	  Say N here if you are unsure.

	  Say N here if you are unsure.





config RCU_KTHREAD_PRIO

	int "Real-time priority to use for RCU worker threads"

	range 1 99 if RCU_BOOST

	range 0 99 if !RCU_BOOST

	default 1 if RCU_BOOST

	default 0 if !RCU_BOOST

	depends on RCU_EXPERT

	help

	  This option specifies the SCHED_FIFO priority value that will be

	  assigned to the rcuc/n and rcub/n threads and is also the value

	  used for RCU_BOOST (if enabled). If you are working with a

	  real-time application that has one or more CPU-bound threads

	  running at a real-time priority level, you should set

	  RCU_KTHREAD_PRIO to a priority higher than the highest-priority

	  real-time CPU-bound application thread.  The default RCU_KTHREAD_PRIO

	  value of 1 is appropriate in the common case, which is real-time

	  applications that do not have any CPU-bound threads.



	  Some real-time applications might not have a single real-time

	  thread that saturates a given CPU, but instead might have

	  multiple real-time threads that, taken together, fully utilize

	  that CPU.  In this case, you should set RCU_KTHREAD_PRIO to

	  a priority higher than the lowest-priority thread that is

	  conspiring to prevent the CPU from running any non-real-time

	  tasks.  For example, if one thread at priority 10 and another

	  thread at priority 5 are between themselves fully consuming

	  the CPU time on a given CPU, then RCU_KTHREAD_PRIO should be

	  set to priority 6 or higher.



	  Specify the real-time priority, or take the default if unsure.



config RCU_BOOST_DELAY

config RCU_BOOST_DELAY

	int "Milliseconds to delay boosting after RCU grace-period start"

	int "Milliseconds to delay boosting after RCU grace-period start"

	range 0 3000

	range 0 3000

kernel/rcu/tree.c

+0 −4
Original line number Original line Diff line number Diff line
@@ -168,11 +168,7 @@ static void rcu_report_exp_rdp(struct rcu_state *rsp, 
static void sync_sched_exp_online_cleanup(int cpu);

static void sync_sched_exp_online_cleanup(int cpu);





/* rcuc/rcub kthread realtime priority */

/* rcuc/rcub kthread realtime priority */

#ifdef CONFIG_RCU_KTHREAD_PRIO

static int kthread_prio = CONFIG_RCU_KTHREAD_PRIO;

#else /* #ifdef CONFIG_RCU_KTHREAD_PRIO */

static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0;

static int kthread_prio = IS_ENABLED(CONFIG_RCU_BOOST) ? 1 : 0;

#endif /* #else #ifdef CONFIG_RCU_KTHREAD_PRIO */

module_param(kthread_prio, int, 0644);

module_param(kthread_prio, int, 0644);





/* Delay in jiffies for grace-period initialization delays, debug only. */

/* Delay in jiffies for grace-period initialization delays, debug only. */

tools/testing/selftests/rcutorture/configs/rcu/TREE03

+0 −1
Original line number Original line Diff line number Diff line
@@ -14,6 +14,5 @@ CONFIG_RCU_FANOUT_LEAF=2 
CONFIG_RCU_NOCB_CPU=n

CONFIG_RCU_NOCB_CPU=n

CONFIG_DEBUG_LOCK_ALLOC=n

CONFIG_DEBUG_LOCK_ALLOC=n

CONFIG_RCU_BOOST=y

CONFIG_RCU_BOOST=y

CONFIG_RCU_KTHREAD_PRIO=2

CONFIG_DEBUG_OBJECTS_RCU_HEAD=n

CONFIG_DEBUG_OBJECTS_RCU_HEAD=n

CONFIG_RCU_EXPERT=y
 
CONFIG_RCU_EXPERT=y

tools/testing/selftests/rcutorture/configs/rcu/TREE03.boot

+1 −0
Original line number Original line Diff line number Diff line
@@ -2,3 +2,4 @@ rcutorture.onoff_interval=1 rcutorture.onoff_holdoff=30 
rcutree.gp_preinit_delay=3

rcutree.gp_preinit_delay=3

rcutree.gp_init_delay=3

rcutree.gp_init_delay=3

rcutree.gp_cleanup_delay=3

rcutree.gp_cleanup_delay=3

rcutree.kthread_prio=2

tools/testing/selftests/rcutorture/doc/TREE_RCU-kconfig.txt

+0 −1
Original line number Original line Diff line number Diff line
@@ -16,7 +16,6 @@ CONFIG_PROVE_LOCKING -- Do several, covering CONFIG_DEBUG_LOCK_ALLOC=y and not. 
CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.

CONFIG_PROVE_RCU -- Hardwired to CONFIG_PROVE_LOCKING.

CONFIG_PROVE_RCU_REPEATEDLY -- Do one.

CONFIG_PROVE_RCU_REPEATEDLY -- Do one.

CONFIG_RCU_BOOST -- one of PREEMPT_RCU.

CONFIG_RCU_BOOST -- one of PREEMPT_RCU.

CONFIG_RCU_KTHREAD_PRIO -- set to 2 for _BOOST testing.

CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.

CONFIG_RCU_FANOUT -- Cover hierarchy, but overlap with others.

CONFIG_RCU_FANOUT_LEAF -- Do one non-default.

CONFIG_RCU_FANOUT_LEAF -- Do one non-default.

CONFIG_RCU_FAST_NO_HZ -- Do one, but not with CONFIG_RCU_NOCB_CPU_ALL.

CONFIG_RCU_FAST_NO_HZ -- Do one, but not with CONFIG_RCU_NOCB_CPU_ALL.