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rcu: Make CPU_DYING_IDLE an explicit call

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Make the RCU CPU_DYING_IDLE callback an explicit function call, so it gets
invoked at the proper place.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: Rik van Riel <riel@redhat.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/20160226182341.870167933@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Thomas Gleixner 2016-02-26 18:43:44 +00:00
parent e69aab1311
commit 27d50c7eeb
6 changed files with 42 additions and 41 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
include/linux/cpu.h
View file

@ -101,9 +101,7 @@ enum {
* Called on the new cpu, just before
* enabling interrupts. Must not sleep,
* must not fail */
#define CPU_DYING_IDLE 0x000B /* CPU (unsigned)v dying, reached
* idle loop. */
#define CPU_BROKEN 0x000C /* CPU (unsigned)v did not die properly,
#define CPU_BROKEN 0x000B /* CPU (unsigned)v did not die properly,
* perhaps due to preemption. */
/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend

2
include/linux/notifier.h
View file

@ -47,6 +47,8 @@
* runtime initialization.
*/
struct notifier_block;
typedef int (*notifier_fn_t)(struct notifier_block *nb,
unsigned long action, void *data);

4
include/linux/rcupdate.h
View file

@ -332,9 +332,7 @@ void rcu_init(void);
void rcu_sched_qs(void);
void rcu_bh_qs(void);
void rcu_check_callbacks(int user);
struct notifier_block;
int rcu_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu);
void rcu_report_dead(unsigned int cpu);
#ifndef CONFIG_TINY_RCU
void rcu_end_inkernel_boot(void);

1
kernel/cpu.c
View file

@ -762,6 +762,7 @@ void cpuhp_report_idle_dead(void)
BUG_ON(st->state != CPUHP_AP_OFFLINE);
st->state = CPUHP_AP_IDLE_DEAD;
complete(&st->done);
rcu_report_dead(smp_processor_id());
}
#else

70
kernel/rcu/tree.c
View file

@ -2606,28 +2606,6 @@ static void rcu_cleanup_dead_rnp(struct rcu_node *rnp_leaf)
}
}
/*
* The CPU is exiting the idle loop into the arch_cpu_idle_dead()
* function. We now remove it from the rcu_node tree's ->qsmaskinit
* bit masks.
*/
static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
{
unsigned long flags;
unsigned long mask;
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
return;
/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
mask = rdp->grpmask;
raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
rnp->qsmaskinitnext &= ~mask;
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
/*
* The CPU has been completely removed, and some other CPU is reporting
* this fact from process context. Do the remainder of the cleanup,
@ -4247,6 +4225,43 @@ static void rcu_prepare_cpu(int cpu)
rcu_init_percpu_data(cpu, rsp);
}
#ifdef CONFIG_HOTPLUG_CPU
/*
* The CPU is exiting the idle loop into the arch_cpu_idle_dead()
* function. We now remove it from the rcu_node tree's ->qsmaskinit
* bit masks.
*/
static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
{
unsigned long flags;
unsigned long mask;
struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
return;
/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
mask = rdp->grpmask;
raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
rnp->qsmaskinitnext &= ~mask;
raw_spin_unlock_irqrestore(&rnp->lock, flags);
}
void rcu_report_dead(unsigned int cpu)
{
struct rcu_state *rsp;
/* QS for any half-done expedited RCU-sched GP. */
preempt_disable();
rcu_report_exp_rdp(&rcu_sched_state,
this_cpu_ptr(rcu_sched_state.rda), true);
preempt_enable();
for_each_rcu_flavor(rsp)
rcu_cleanup_dying_idle_cpu(cpu, rsp);
}
#endif
/*
* Handle CPU online/offline notification events.
*/
@ -4278,17 +4293,6 @@ int rcu_cpu_notify(struct notifier_block *self,
for_each_rcu_flavor(rsp)
rcu_cleanup_dying_cpu(rsp);
break;
case CPU_DYING_IDLE:
/* QS for any half-done expedited RCU-sched GP. */
preempt_disable();
rcu_report_exp_rdp(&rcu_sched_state,
this_cpu_ptr(rcu_sched_state.rda), true);
preempt_enable();
for_each_rcu_flavor(rsp) {
rcu_cleanup_dying_idle_cpu(cpu, rsp);
}
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
case CPU_UP_CANCELED:

2
kernel/sched/idle.c
View file

@ -220,8 +220,6 @@ static void cpu_idle_loop(void)
rmb();
if (cpu_is_offline(smp_processor_id())) {
rcu_cpu_notify(NULL, CPU_DYING_IDLE,
(void *)(long)smp_processor_id());
cpuhp_report_idle_dead();
arch_cpu_idle_dead();
}