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rcu: Eliminate NOCBs CPU-state Kconfig options

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The CONFIG_RCU_NOCB_CPU_ALL, CONFIG_RCU_NOCB_CPU_NONE, and
CONFIG_RCU_NOCB_CPU_ZERO Kconfig options are used only in testing and
are redundant with the rcu_nocbs= boot parameter.  This commit therefore
removes these three Kconfig options and adjusts the rcutorture scripts
to use the boot parameter instead.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
2017-05-15 16:26:34 -07:00
parent ae91aa0adb
commit 44c65ff2e3
11 changed files with 26 additions and 131 deletions
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4
kernel/rcu/rcu.h
View File

@@ -564,9 +564,7 @@ void rcu_bh_force_quiescent_state(void);
void rcu_sched_force_quiescent_state(void);
#endif /* #else #ifdef CONFIG_TINY_RCU */
#if defined(CONFIG_RCU_NOCB_CPU_ALL)
static inline bool rcu_is_nocb_cpu(int cpu) { return true; }
#elif defined(CONFIG_RCU_NOCB_CPU)
#ifdef CONFIG_RCU_NOCB_CPU
bool rcu_is_nocb_cpu(int cpu);
#else
static inline bool rcu_is_nocb_cpu(int cpu) { return false; }

27
kernel/rcu/tree_plugin.h
View File

@@ -1296,8 +1296,7 @@ static void rcu_prepare_kthreads(int cpu)
int rcu_needs_cpu(u64 basemono, u64 *nextevt)
{
*nextevt = KTIME_MAX;
return IS_ENABLED(CONFIG_RCU_NOCB_CPU_ALL)
? 0 : rcu_cpu_has_callbacks(NULL);
return rcu_cpu_has_callbacks(NULL);
}
/*
@@ -1409,10 +1408,6 @@ int rcu_needs_cpu(u64 basemono, u64 *nextevt)
unsigned long dj;
RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_needs_cpu() invoked with irqs enabled!!!");
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU_ALL)) {
*nextevt = KTIME_MAX;
return 0;
}
/* Snapshot to detect later posting of non-lazy callback. */
rdtp->nonlazy_posted_snap = rdtp->nonlazy_posted;
@@ -1462,8 +1457,7 @@ static void rcu_prepare_for_idle(void)
int tne;
RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_prepare_for_idle() invoked with irqs enabled!!!");
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU_ALL) ||
rcu_is_nocb_cpu(smp_processor_id()))
if (rcu_is_nocb_cpu(smp_processor_id()))
return;
/* Handle nohz enablement switches conservatively. */
@@ -1518,8 +1512,7 @@ static void rcu_prepare_for_idle(void)
static void rcu_cleanup_after_idle(void)
{
RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_cleanup_after_idle() invoked with irqs enabled!!!");
if (IS_ENABLED(CONFIG_RCU_NOCB_CPU_ALL) ||
rcu_is_nocb_cpu(smp_processor_id()))
if (rcu_is_nocb_cpu(smp_processor_id()))
return;
if (rcu_try_advance_all_cbs())
invoke_rcu_core();
@@ -1786,7 +1779,6 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
init_swait_queue_head(&rnp->nocb_gp_wq[1]);
}
#ifndef CONFIG_RCU_NOCB_CPU_ALL
/* Is the specified CPU a no-CBs CPU? */
bool rcu_is_nocb_cpu(int cpu)
{
@@ -1794,7 +1786,6 @@ bool rcu_is_nocb_cpu(int cpu)
return cpumask_test_cpu(cpu, rcu_nocb_mask);
return false;
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
/*
* Kick the leader kthread for this NOCB group.
@@ -2253,10 +2244,6 @@ void __init rcu_init_nohz(void)
bool need_rcu_nocb_mask = true;
struct rcu_state *rsp;
#ifdef CONFIG_RCU_NOCB_CPU_NONE
need_rcu_nocb_mask = false;
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */
#if defined(CONFIG_NO_HZ_FULL)
if (tick_nohz_full_running && cpumask_weight(tick_nohz_full_mask))
need_rcu_nocb_mask = true;
@@ -2272,14 +2259,6 @@ void __init rcu_init_nohz(void)
if (!have_rcu_nocb_mask)
return;
#ifdef CONFIG_RCU_NOCB_CPU_ZERO
pr_info("\tOffload RCU callbacks from CPU 0\n");
cpumask_set_cpu(0, rcu_nocb_mask);
#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */
#ifdef CONFIG_RCU_NOCB_CPU_ALL
pr_info("\tOffload RCU callbacks from all CPUs\n");
cpumask_copy(rcu_nocb_mask, cpu_possible_mask);
#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */
#if defined(CONFIG_NO_HZ_FULL)
if (tick_nohz_full_running)
cpumask_or(rcu_nocb_mask, rcu_nocb_mask, tick_nohz_full_mask);