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![Paul E. McKenney](/assets/img/avatar_default.png)
Kernels configured with CONFIG_PRINTK=n and CONFIG_SRCU=n get build failures. This causes trouble for deep embedded systems. But given that there are more than 25 instances of "select SRCU" in the kernel, it is hard to believe that there are many kernels running in production without SRCU. This commit therefore makes SRCU mandatory. The SRCU Kconfig option remains for backwards compatibility, and will be removed when it is no longer used. [ paulmck: Update per kernel test robot feedback. ] Reported-by: John Ogness <john.ogness@linutronix.de> Reported-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: <linux-arch@vger.kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Reviewed-by: John Ogness <john.ogness@linutronix.de>
624 lines
18 KiB
C
624 lines
18 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Read-Copy Update mechanism for mutual exclusion
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*
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* Copyright IBM Corporation, 2001
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*
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* Authors: Dipankar Sarma <dipankar@in.ibm.com>
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* Manfred Spraul <manfred@colorfullife.com>
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*
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* Based on the original work by Paul McKenney <paulmck@linux.ibm.com>
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* and inputs from Rusty Russell, Andrea Arcangeli and Andi Kleen.
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* Papers:
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* http://www.rdrop.com/users/paulmck/paper/rclockpdcsproof.pdf
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* http://lse.sourceforge.net/locking/rclock_OLS.2001.05.01c.sc.pdf (OLS2001)
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*
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* For detailed explanation of Read-Copy Update mechanism see -
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* http://lse.sourceforge.net/locking/rcupdate.html
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*
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/smp.h>
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#include <linux/interrupt.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/debug.h>
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#include <linux/atomic.h>
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#include <linux/bitops.h>
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#include <linux/percpu.h>
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#include <linux/notifier.h>
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#include <linux/cpu.h>
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#include <linux/mutex.h>
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#include <linux/export.h>
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#include <linux/hardirq.h>
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#include <linux/delay.h>
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#include <linux/moduleparam.h>
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#include <linux/kthread.h>
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#include <linux/tick.h>
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#include <linux/rcupdate_wait.h>
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#include <linux/sched/isolation.h>
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#include <linux/kprobes.h>
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#include <linux/slab.h>
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#include <linux/irq_work.h>
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#include <linux/rcupdate_trace.h>
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#define CREATE_TRACE_POINTS
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#include "rcu.h"
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#ifdef MODULE_PARAM_PREFIX
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#undef MODULE_PARAM_PREFIX
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#endif
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#define MODULE_PARAM_PREFIX "rcupdate."
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#ifndef CONFIG_TINY_RCU
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module_param(rcu_expedited, int, 0444);
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module_param(rcu_normal, int, 0444);
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static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT);
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#if !defined(CONFIG_PREEMPT_RT) || defined(CONFIG_NO_HZ_FULL)
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module_param(rcu_normal_after_boot, int, 0444);
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#endif
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#endif /* #ifndef CONFIG_TINY_RCU */
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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/**
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* rcu_read_lock_held_common() - might we be in RCU-sched read-side critical section?
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* @ret: Best guess answer if lockdep cannot be relied on
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*
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* Returns true if lockdep must be ignored, in which case ``*ret`` contains
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* the best guess described below. Otherwise returns false, in which
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* case ``*ret`` tells the caller nothing and the caller should instead
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* consult lockdep.
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*
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* If CONFIG_DEBUG_LOCK_ALLOC is selected, set ``*ret`` to nonzero iff in an
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* RCU-sched read-side critical section. In absence of
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* CONFIG_DEBUG_LOCK_ALLOC, this assumes we are in an RCU-sched read-side
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* critical section unless it can prove otherwise. Note that disabling
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* of preemption (including disabling irqs) counts as an RCU-sched
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* read-side critical section. This is useful for debug checks in functions
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* that required that they be called within an RCU-sched read-side
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* critical section.
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*
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* Check debug_lockdep_rcu_enabled() to prevent false positives during boot
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* and while lockdep is disabled.
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*
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* Note that if the CPU is in the idle loop from an RCU point of view (ie:
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* that we are in the section between ct_idle_enter() and ct_idle_exit())
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* then rcu_read_lock_held() sets ``*ret`` to false even if the CPU did an
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* rcu_read_lock(). The reason for this is that RCU ignores CPUs that are
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* in such a section, considering these as in extended quiescent state,
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* so such a CPU is effectively never in an RCU read-side critical section
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* regardless of what RCU primitives it invokes. This state of affairs is
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* required --- we need to keep an RCU-free window in idle where the CPU may
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* possibly enter into low power mode. This way we can notice an extended
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* quiescent state to other CPUs that started a grace period. Otherwise
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* we would delay any grace period as long as we run in the idle task.
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*
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* Similarly, we avoid claiming an RCU read lock held if the current
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* CPU is offline.
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*/
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static bool rcu_read_lock_held_common(bool *ret)
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{
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if (!debug_lockdep_rcu_enabled()) {
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*ret = true;
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return true;
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}
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if (!rcu_is_watching()) {
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*ret = false;
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return true;
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}
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if (!rcu_lockdep_current_cpu_online()) {
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*ret = false;
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return true;
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}
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return false;
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}
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int rcu_read_lock_sched_held(void)
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{
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bool ret;
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if (rcu_read_lock_held_common(&ret))
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return ret;
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return lock_is_held(&rcu_sched_lock_map) || !preemptible();
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}
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EXPORT_SYMBOL(rcu_read_lock_sched_held);
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#endif
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#ifndef CONFIG_TINY_RCU
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/*
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* Should expedited grace-period primitives always fall back to their
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* non-expedited counterparts? Intended for use within RCU. Note
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* that if the user specifies both rcu_expedited and rcu_normal, then
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* rcu_normal wins. (Except during the time period during boot from
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* when the first task is spawned until the rcu_set_runtime_mode()
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* core_initcall() is invoked, at which point everything is expedited.)
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*/
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bool rcu_gp_is_normal(void)
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{
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return READ_ONCE(rcu_normal) &&
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rcu_scheduler_active != RCU_SCHEDULER_INIT;
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}
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EXPORT_SYMBOL_GPL(rcu_gp_is_normal);
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static atomic_t rcu_expedited_nesting = ATOMIC_INIT(1);
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/*
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* Should normal grace-period primitives be expedited? Intended for
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* use within RCU. Note that this function takes the rcu_expedited
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* sysfs/boot variable and rcu_scheduler_active into account as well
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* as the rcu_expedite_gp() nesting. So looping on rcu_unexpedite_gp()
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* until rcu_gp_is_expedited() returns false is a -really- bad idea.
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*/
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bool rcu_gp_is_expedited(void)
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{
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return rcu_expedited || atomic_read(&rcu_expedited_nesting);
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}
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EXPORT_SYMBOL_GPL(rcu_gp_is_expedited);
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/**
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* rcu_expedite_gp - Expedite future RCU grace periods
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*
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* After a call to this function, future calls to synchronize_rcu() and
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* friends act as the corresponding synchronize_rcu_expedited() function
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* had instead been called.
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*/
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void rcu_expedite_gp(void)
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{
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atomic_inc(&rcu_expedited_nesting);
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}
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EXPORT_SYMBOL_GPL(rcu_expedite_gp);
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/**
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* rcu_unexpedite_gp - Cancel prior rcu_expedite_gp() invocation
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*
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* Undo a prior call to rcu_expedite_gp(). If all prior calls to
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* rcu_expedite_gp() are undone by a subsequent call to rcu_unexpedite_gp(),
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* and if the rcu_expedited sysfs/boot parameter is not set, then all
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* subsequent calls to synchronize_rcu() and friends will return to
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* their normal non-expedited behavior.
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*/
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void rcu_unexpedite_gp(void)
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{
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atomic_dec(&rcu_expedited_nesting);
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}
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EXPORT_SYMBOL_GPL(rcu_unexpedite_gp);
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static bool rcu_boot_ended __read_mostly;
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/*
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* Inform RCU of the end of the in-kernel boot sequence.
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*/
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void rcu_end_inkernel_boot(void)
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{
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rcu_unexpedite_gp();
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if (rcu_normal_after_boot)
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WRITE_ONCE(rcu_normal, 1);
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rcu_boot_ended = true;
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}
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/*
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* Let rcutorture know when it is OK to turn it up to eleven.
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*/
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bool rcu_inkernel_boot_has_ended(void)
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{
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return rcu_boot_ended;
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}
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EXPORT_SYMBOL_GPL(rcu_inkernel_boot_has_ended);
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#endif /* #ifndef CONFIG_TINY_RCU */
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/*
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* Test each non-SRCU synchronous grace-period wait API. This is
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* useful just after a change in mode for these primitives, and
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* during early boot.
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*/
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void rcu_test_sync_prims(void)
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{
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if (!IS_ENABLED(CONFIG_PROVE_RCU))
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return;
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synchronize_rcu();
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synchronize_rcu_expedited();
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}
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#if !defined(CONFIG_TINY_RCU)
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/*
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* Switch to run-time mode once RCU has fully initialized.
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*/
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static int __init rcu_set_runtime_mode(void)
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{
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rcu_test_sync_prims();
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rcu_scheduler_active = RCU_SCHEDULER_RUNNING;
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kfree_rcu_scheduler_running();
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rcu_test_sync_prims();
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return 0;
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}
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core_initcall(rcu_set_runtime_mode);
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#endif /* #if !defined(CONFIG_TINY_RCU) */
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#ifdef CONFIG_DEBUG_LOCK_ALLOC
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static struct lock_class_key rcu_lock_key;
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struct lockdep_map rcu_lock_map = {
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.name = "rcu_read_lock",
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.key = &rcu_lock_key,
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.wait_type_outer = LD_WAIT_FREE,
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.wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_RT implies PREEMPT_RCU */
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};
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EXPORT_SYMBOL_GPL(rcu_lock_map);
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static struct lock_class_key rcu_bh_lock_key;
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struct lockdep_map rcu_bh_lock_map = {
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.name = "rcu_read_lock_bh",
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.key = &rcu_bh_lock_key,
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.wait_type_outer = LD_WAIT_FREE,
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.wait_type_inner = LD_WAIT_CONFIG, /* PREEMPT_RT makes BH preemptible. */
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};
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EXPORT_SYMBOL_GPL(rcu_bh_lock_map);
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static struct lock_class_key rcu_sched_lock_key;
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struct lockdep_map rcu_sched_lock_map = {
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.name = "rcu_read_lock_sched",
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.key = &rcu_sched_lock_key,
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.wait_type_outer = LD_WAIT_FREE,
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.wait_type_inner = LD_WAIT_SPIN,
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};
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EXPORT_SYMBOL_GPL(rcu_sched_lock_map);
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// Tell lockdep when RCU callbacks are being invoked.
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static struct lock_class_key rcu_callback_key;
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struct lockdep_map rcu_callback_map =
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STATIC_LOCKDEP_MAP_INIT("rcu_callback", &rcu_callback_key);
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EXPORT_SYMBOL_GPL(rcu_callback_map);
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noinstr int notrace debug_lockdep_rcu_enabled(void)
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{
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return rcu_scheduler_active != RCU_SCHEDULER_INACTIVE && READ_ONCE(debug_locks) &&
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current->lockdep_recursion == 0;
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}
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EXPORT_SYMBOL_GPL(debug_lockdep_rcu_enabled);
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/**
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* rcu_read_lock_held() - might we be in RCU read-side critical section?
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*
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* If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an RCU
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* read-side critical section. In absence of CONFIG_DEBUG_LOCK_ALLOC,
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* this assumes we are in an RCU read-side critical section unless it can
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* prove otherwise. This is useful for debug checks in functions that
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* require that they be called within an RCU read-side critical section.
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*
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* Checks debug_lockdep_rcu_enabled() to prevent false positives during boot
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* and while lockdep is disabled.
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*
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* Note that rcu_read_lock() and the matching rcu_read_unlock() must
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* occur in the same context, for example, it is illegal to invoke
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* rcu_read_unlock() in process context if the matching rcu_read_lock()
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* was invoked from within an irq handler.
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*
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* Note that rcu_read_lock() is disallowed if the CPU is either idle or
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* offline from an RCU perspective, so check for those as well.
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*/
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int rcu_read_lock_held(void)
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{
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bool ret;
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if (rcu_read_lock_held_common(&ret))
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return ret;
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return lock_is_held(&rcu_lock_map);
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}
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EXPORT_SYMBOL_GPL(rcu_read_lock_held);
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/**
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* rcu_read_lock_bh_held() - might we be in RCU-bh read-side critical section?
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*
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* Check for bottom half being disabled, which covers both the
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* CONFIG_PROVE_RCU and not cases. Note that if someone uses
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* rcu_read_lock_bh(), but then later enables BH, lockdep (if enabled)
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* will show the situation. This is useful for debug checks in functions
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* that require that they be called within an RCU read-side critical
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* section.
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*
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* Check debug_lockdep_rcu_enabled() to prevent false positives during boot.
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*
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* Note that rcu_read_lock_bh() is disallowed if the CPU is either idle or
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* offline from an RCU perspective, so check for those as well.
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*/
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int rcu_read_lock_bh_held(void)
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{
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bool ret;
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if (rcu_read_lock_held_common(&ret))
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return ret;
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return in_softirq() || irqs_disabled();
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}
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EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
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int rcu_read_lock_any_held(void)
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{
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bool ret;
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if (rcu_read_lock_held_common(&ret))
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return ret;
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if (lock_is_held(&rcu_lock_map) ||
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lock_is_held(&rcu_bh_lock_map) ||
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lock_is_held(&rcu_sched_lock_map))
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return 1;
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return !preemptible();
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}
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EXPORT_SYMBOL_GPL(rcu_read_lock_any_held);
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#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
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/**
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* wakeme_after_rcu() - Callback function to awaken a task after grace period
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* @head: Pointer to rcu_head member within rcu_synchronize structure
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*
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* Awaken the corresponding task now that a grace period has elapsed.
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*/
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void wakeme_after_rcu(struct rcu_head *head)
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{
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struct rcu_synchronize *rcu;
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rcu = container_of(head, struct rcu_synchronize, head);
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complete(&rcu->completion);
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}
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EXPORT_SYMBOL_GPL(wakeme_after_rcu);
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void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
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struct rcu_synchronize *rs_array)
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{
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int i;
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int j;
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/* Initialize and register callbacks for each crcu_array element. */
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for (i = 0; i < n; i++) {
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if (checktiny &&
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(crcu_array[i] == call_rcu)) {
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might_sleep();
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continue;
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}
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for (j = 0; j < i; j++)
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if (crcu_array[j] == crcu_array[i])
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break;
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if (j == i) {
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init_rcu_head_on_stack(&rs_array[i].head);
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init_completion(&rs_array[i].completion);
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(crcu_array[i])(&rs_array[i].head, wakeme_after_rcu);
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}
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}
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/* Wait for all callbacks to be invoked. */
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for (i = 0; i < n; i++) {
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if (checktiny &&
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(crcu_array[i] == call_rcu))
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continue;
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for (j = 0; j < i; j++)
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if (crcu_array[j] == crcu_array[i])
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break;
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if (j == i) {
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wait_for_completion(&rs_array[i].completion);
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destroy_rcu_head_on_stack(&rs_array[i].head);
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}
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}
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}
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EXPORT_SYMBOL_GPL(__wait_rcu_gp);
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void finish_rcuwait(struct rcuwait *w)
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{
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rcu_assign_pointer(w->task, NULL);
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__set_current_state(TASK_RUNNING);
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}
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EXPORT_SYMBOL_GPL(finish_rcuwait);
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#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
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void init_rcu_head(struct rcu_head *head)
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{
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debug_object_init(head, &rcuhead_debug_descr);
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}
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EXPORT_SYMBOL_GPL(init_rcu_head);
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void destroy_rcu_head(struct rcu_head *head)
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{
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debug_object_free(head, &rcuhead_debug_descr);
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}
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EXPORT_SYMBOL_GPL(destroy_rcu_head);
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static bool rcuhead_is_static_object(void *addr)
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{
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return true;
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}
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/**
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* init_rcu_head_on_stack() - initialize on-stack rcu_head for debugobjects
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* @head: pointer to rcu_head structure to be initialized
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*
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* This function informs debugobjects of a new rcu_head structure that
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* has been allocated as an auto variable on the stack. This function
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* is not required for rcu_head structures that are statically defined or
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* that are dynamically allocated on the heap. This function has no
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* effect for !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
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*/
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void init_rcu_head_on_stack(struct rcu_head *head)
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{
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debug_object_init_on_stack(head, &rcuhead_debug_descr);
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}
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EXPORT_SYMBOL_GPL(init_rcu_head_on_stack);
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/**
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* destroy_rcu_head_on_stack() - destroy on-stack rcu_head for debugobjects
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* @head: pointer to rcu_head structure to be initialized
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*
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* This function informs debugobjects that an on-stack rcu_head structure
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* is about to go out of scope. As with init_rcu_head_on_stack(), this
|
|
* function is not required for rcu_head structures that are statically
|
|
* defined or that are dynamically allocated on the heap. Also as with
|
|
* init_rcu_head_on_stack(), this function has no effect for
|
|
* !CONFIG_DEBUG_OBJECTS_RCU_HEAD kernel builds.
|
|
*/
|
|
void destroy_rcu_head_on_stack(struct rcu_head *head)
|
|
{
|
|
debug_object_free(head, &rcuhead_debug_descr);
|
|
}
|
|
EXPORT_SYMBOL_GPL(destroy_rcu_head_on_stack);
|
|
|
|
const struct debug_obj_descr rcuhead_debug_descr = {
|
|
.name = "rcu_head",
|
|
.is_static_object = rcuhead_is_static_object,
|
|
};
|
|
EXPORT_SYMBOL_GPL(rcuhead_debug_descr);
|
|
#endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
|
|
|
|
#if defined(CONFIG_TREE_RCU) || defined(CONFIG_RCU_TRACE)
|
|
void do_trace_rcu_torture_read(const char *rcutorturename, struct rcu_head *rhp,
|
|
unsigned long secs,
|
|
unsigned long c_old, unsigned long c)
|
|
{
|
|
trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c);
|
|
}
|
|
EXPORT_SYMBOL_GPL(do_trace_rcu_torture_read);
|
|
#else
|
|
#define do_trace_rcu_torture_read(rcutorturename, rhp, secs, c_old, c) \
|
|
do { } while (0)
|
|
#endif
|
|
|
|
#if IS_ENABLED(CONFIG_RCU_TORTURE_TEST) || IS_MODULE(CONFIG_RCU_TORTURE_TEST)
|
|
/* Get rcutorture access to sched_setaffinity(). */
|
|
long rcutorture_sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
|
|
{
|
|
int ret;
|
|
|
|
ret = sched_setaffinity(pid, in_mask);
|
|
WARN_ONCE(ret, "%s: sched_setaffinity() returned %d\n", __func__, ret);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(rcutorture_sched_setaffinity);
|
|
#endif
|
|
|
|
#ifdef CONFIG_RCU_STALL_COMMON
|
|
int rcu_cpu_stall_ftrace_dump __read_mostly;
|
|
module_param(rcu_cpu_stall_ftrace_dump, int, 0644);
|
|
int rcu_cpu_stall_suppress __read_mostly; // !0 = suppress stall warnings.
|
|
EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress);
|
|
module_param(rcu_cpu_stall_suppress, int, 0644);
|
|
int rcu_cpu_stall_timeout __read_mostly = CONFIG_RCU_CPU_STALL_TIMEOUT;
|
|
module_param(rcu_cpu_stall_timeout, int, 0644);
|
|
int rcu_exp_cpu_stall_timeout __read_mostly = CONFIG_RCU_EXP_CPU_STALL_TIMEOUT;
|
|
module_param(rcu_exp_cpu_stall_timeout, int, 0644);
|
|
#endif /* #ifdef CONFIG_RCU_STALL_COMMON */
|
|
|
|
// Suppress boot-time RCU CPU stall warnings and rcutorture writer stall
|
|
// warnings. Also used by rcutorture even if stall warnings are excluded.
|
|
int rcu_cpu_stall_suppress_at_boot __read_mostly; // !0 = suppress boot stalls.
|
|
EXPORT_SYMBOL_GPL(rcu_cpu_stall_suppress_at_boot);
|
|
module_param(rcu_cpu_stall_suppress_at_boot, int, 0444);
|
|
|
|
/**
|
|
* get_completed_synchronize_rcu - Return a pre-completed polled state cookie
|
|
*
|
|
* Returns a value that will always be treated by functions like
|
|
* poll_state_synchronize_rcu() as a cookie whose grace period has already
|
|
* completed.
|
|
*/
|
|
unsigned long get_completed_synchronize_rcu(void)
|
|
{
|
|
return RCU_GET_STATE_COMPLETED;
|
|
}
|
|
EXPORT_SYMBOL_GPL(get_completed_synchronize_rcu);
|
|
|
|
#ifdef CONFIG_PROVE_RCU
|
|
|
|
/*
|
|
* Early boot self test parameters.
|
|
*/
|
|
static bool rcu_self_test;
|
|
module_param(rcu_self_test, bool, 0444);
|
|
|
|
static int rcu_self_test_counter;
|
|
|
|
static void test_callback(struct rcu_head *r)
|
|
{
|
|
rcu_self_test_counter++;
|
|
pr_info("RCU test callback executed %d\n", rcu_self_test_counter);
|
|
}
|
|
|
|
DEFINE_STATIC_SRCU(early_srcu);
|
|
static unsigned long early_srcu_cookie;
|
|
|
|
struct early_boot_kfree_rcu {
|
|
struct rcu_head rh;
|
|
};
|
|
|
|
static void early_boot_test_call_rcu(void)
|
|
{
|
|
static struct rcu_head head;
|
|
static struct rcu_head shead;
|
|
struct early_boot_kfree_rcu *rhp;
|
|
|
|
call_rcu(&head, test_callback);
|
|
early_srcu_cookie = start_poll_synchronize_srcu(&early_srcu);
|
|
call_srcu(&early_srcu, &shead, test_callback);
|
|
rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
|
|
if (!WARN_ON_ONCE(!rhp))
|
|
kfree_rcu(rhp, rh);
|
|
}
|
|
|
|
void rcu_early_boot_tests(void)
|
|
{
|
|
pr_info("Running RCU self tests\n");
|
|
|
|
if (rcu_self_test)
|
|
early_boot_test_call_rcu();
|
|
rcu_test_sync_prims();
|
|
}
|
|
|
|
static int rcu_verify_early_boot_tests(void)
|
|
{
|
|
int ret = 0;
|
|
int early_boot_test_counter = 0;
|
|
|
|
if (rcu_self_test) {
|
|
early_boot_test_counter++;
|
|
rcu_barrier();
|
|
early_boot_test_counter++;
|
|
srcu_barrier(&early_srcu);
|
|
WARN_ON_ONCE(!poll_state_synchronize_srcu(&early_srcu, early_srcu_cookie));
|
|
}
|
|
if (rcu_self_test_counter != early_boot_test_counter) {
|
|
WARN_ON(1);
|
|
ret = -1;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
late_initcall(rcu_verify_early_boot_tests);
|
|
#else
|
|
void rcu_early_boot_tests(void) {}
|
|
#endif /* CONFIG_PROVE_RCU */
|
|
|
|
#include "tasks.h"
|
|
|
|
#ifndef CONFIG_TINY_RCU
|
|
|
|
/*
|
|
* Print any significant non-default boot-time settings.
|
|
*/
|
|
void __init rcupdate_announce_bootup_oddness(void)
|
|
{
|
|
if (rcu_normal)
|
|
pr_info("\tNo expedited grace period (rcu_normal).\n");
|
|
else if (rcu_normal_after_boot)
|
|
pr_info("\tNo expedited grace period (rcu_normal_after_boot).\n");
|
|
else if (rcu_expedited)
|
|
pr_info("\tAll grace periods are expedited (rcu_expedited).\n");
|
|
if (rcu_cpu_stall_suppress)
|
|
pr_info("\tRCU CPU stall warnings suppressed (rcu_cpu_stall_suppress).\n");
|
|
if (rcu_cpu_stall_timeout != CONFIG_RCU_CPU_STALL_TIMEOUT)
|
|
pr_info("\tRCU CPU stall warnings timeout set to %d (rcu_cpu_stall_timeout).\n", rcu_cpu_stall_timeout);
|
|
rcu_tasks_bootup_oddness();
|
|
}
|
|
|
|
#endif /* #ifndef CONFIG_TINY_RCU */
|