Commit-ID: 26730f55c2842b4ee06a5307d58265db7dd26065 Gitweb: http://git.kernel.org/tip/26730f55c2842b4ee06a5307d58265db7dd26065 Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> AuthorDate: Tue, 21 Apr 2015 09:22:14 -0700 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Wed, 27 May 2015 12:59:06 -0700 rcu: Make RCU able to tolerate undefined CONFIG_RCU_KTHREAD_PRIO 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@xxxxxxxxxxxxxxxxxxxx> Reported-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Reviewed-by: Pranith Kumar <bobby.prani@xxxxxxxxx> --- init/Kconfig | 1 + kernel/rcu/tree.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/init/Kconfig b/init/Kconfig index 7817600..af2c93c4 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 1edd112..0e9ce12 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -165,7 +165,11 @@ 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. */ -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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