Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 22/24] rcu: Make RCU able to tolerate undefined CONFIG_RCU_KTHREAD_PRIO | Date | Tue, 12 May 2015 15:30:52 -0700 |
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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
This commit updates the initialization of the kthread_prio boot parameter so that RCU will build even when CONFIG_RCU_KTHREAD_PRIO is undefined. The kthread_prio boot parameter is set to CONFIG_RCU_KTHREAD_PRIO if that is defined, otherwise to 1 if CONFIG_RCU_BOOST is defined and to zero otherwise. This commit then makes CONFIG_RCU_KTHREAD_PRIO depend on CONFIG_RCU_EXPERT, so that Kconfig users won't be asked about CONFIG_RCU_KTHREAD_PRIO unless they want to be.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com> --- init/Kconfig | 1 + kernel/rcu/tree.c | 4 ++++ 2 files changed, 5 insertions(+)
diff --git a/init/Kconfig b/init/Kconfig index 78176001f73b..af2c93c4a105 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -671,6 +671,7 @@ config RCU_KTHREAD_PRIO 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 diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 960054da4ae5..0ab9e711a649 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -160,7 +160,11 @@ static void invoke_rcu_core(void); static void invoke_rcu_callbacks(struct rcu_state *rsp, struct rcu_data *rdp); /* 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; +#endif /* #else #ifdef CONFIG_RCU_KTHREAD_PRIO */ module_param(kthread_prio, int, 0644); /* Delay in jiffies for grace-period initialization delays, debug only. */ -- 1.8.1.5
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