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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-28 11:49:32 +00:00
rcu: Switch dyntick nesting counters to rcu_data structure
This commit removes ->dynticks_nesting and ->dynticks_nmi_nesting from the rcu_dynticks structure and updates the code to access them from the rcu_data structure. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
parent
2dba13f0b6
commit
4c5273bf2b
3 changed files with 43 additions and 40 deletions
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@ -73,7 +73,10 @@
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/* Data structures. */
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static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, rcu_data);
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static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, rcu_data) = {
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.dynticks_nesting = 1,
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.dynticks_nmi_nesting = DYNTICK_IRQ_NONIDLE,
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};
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struct rcu_state rcu_state = {
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.level = { &rcu_state.node[0] },
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.gp_state = RCU_GP_IDLE,
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@ -210,8 +213,6 @@ void rcu_softirq_qs(void)
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#endif
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static DEFINE_PER_CPU(struct rcu_dynticks, rcu_dynticks) = {
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.dynticks_nesting = 1,
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.dynticks_nmi_nesting = DYNTICK_IRQ_NONIDLE,
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.dynticks = ATOMIC_INIT(RCU_DYNTICK_CTRL_CTR),
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};
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@ -378,8 +379,8 @@ static void __maybe_unused rcu_momentary_dyntick_idle(void)
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*/
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static int rcu_is_cpu_rrupt_from_idle(void)
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{
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return __this_cpu_read(rcu_dynticks.dynticks_nesting) <= 0 &&
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__this_cpu_read(rcu_dynticks.dynticks_nmi_nesting) <= 1;
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return __this_cpu_read(rcu_data.dynticks_nesting) <= 0 &&
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__this_cpu_read(rcu_data.dynticks_nmi_nesting) <= 1;
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}
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#define DEFAULT_RCU_BLIMIT 10 /* Maximum callbacks per rcu_do_batch. */
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@ -571,27 +572,27 @@ static struct rcu_node *rcu_get_root(void)
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*/
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static void rcu_eqs_enter(bool user)
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{
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struct rcu_data *rdp;
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struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
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struct rcu_dynticks *rdtp;
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rdtp = this_cpu_ptr(&rcu_dynticks);
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WARN_ON_ONCE(rdtp->dynticks_nmi_nesting != DYNTICK_IRQ_NONIDLE);
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WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0);
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WARN_ON_ONCE(rdp->dynticks_nmi_nesting != DYNTICK_IRQ_NONIDLE);
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WRITE_ONCE(rdp->dynticks_nmi_nesting, 0);
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WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
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rdtp->dynticks_nesting == 0);
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if (rdtp->dynticks_nesting != 1) {
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rdtp->dynticks_nesting--;
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rdp->dynticks_nesting == 0);
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if (rdp->dynticks_nesting != 1) {
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rdp->dynticks_nesting--;
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return;
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}
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lockdep_assert_irqs_disabled();
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trace_rcu_dyntick(TPS("Start"), rdtp->dynticks_nesting, 0, rdtp->dynticks);
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trace_rcu_dyntick(TPS("Start"), rdp->dynticks_nesting, 0, rdtp->dynticks);
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WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
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rdp = this_cpu_ptr(&rcu_data);
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do_nocb_deferred_wakeup(rdp);
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rcu_prepare_for_idle();
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rcu_preempt_deferred_qs(current);
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WRITE_ONCE(rdtp->dynticks_nesting, 0); /* Avoid irq-access tearing. */
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WRITE_ONCE(rdp->dynticks_nesting, 0); /* Avoid irq-access tearing. */
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rcu_dynticks_eqs_enter();
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rcu_dynticks_task_enter();
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}
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@ -634,7 +635,7 @@ void rcu_user_enter(void)
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/*
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* If we are returning from the outermost NMI handler that interrupted an
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* RCU-idle period, update rdtp->dynticks and rdtp->dynticks_nmi_nesting
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* RCU-idle period, update rdtp->dynticks and rdp->dynticks_nmi_nesting
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* to let the RCU grace-period handling know that the CPU is back to
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* being RCU-idle.
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*
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@ -643,30 +644,31 @@ void rcu_user_enter(void)
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*/
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static __always_inline void rcu_nmi_exit_common(bool irq)
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{
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struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
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struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
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struct rcu_dynticks __maybe_unused *rdtp = this_cpu_ptr(&rcu_dynticks);
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/*
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* Check for ->dynticks_nmi_nesting underflow and bad ->dynticks.
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* (We are exiting an NMI handler, so RCU better be paying attention
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* to us!)
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*/
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WARN_ON_ONCE(rdtp->dynticks_nmi_nesting <= 0);
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WARN_ON_ONCE(rdp->dynticks_nmi_nesting <= 0);
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WARN_ON_ONCE(rcu_dynticks_curr_cpu_in_eqs());
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/*
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* If the nesting level is not 1, the CPU wasn't RCU-idle, so
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* leave it in non-RCU-idle state.
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*/
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if (rdtp->dynticks_nmi_nesting != 1) {
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trace_rcu_dyntick(TPS("--="), rdtp->dynticks_nmi_nesting, rdtp->dynticks_nmi_nesting - 2, rdtp->dynticks);
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WRITE_ONCE(rdtp->dynticks_nmi_nesting, /* No store tearing. */
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rdtp->dynticks_nmi_nesting - 2);
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if (rdp->dynticks_nmi_nesting != 1) {
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trace_rcu_dyntick(TPS("--="), rdp->dynticks_nmi_nesting, rdp->dynticks_nmi_nesting - 2, rdtp->dynticks);
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WRITE_ONCE(rdp->dynticks_nmi_nesting, /* No store tearing. */
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rdp->dynticks_nmi_nesting - 2);
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return;
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}
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/* This NMI interrupted an RCU-idle CPU, restore RCU-idleness. */
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trace_rcu_dyntick(TPS("Startirq"), rdtp->dynticks_nmi_nesting, 0, rdtp->dynticks);
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WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0); /* Avoid store tearing. */
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trace_rcu_dyntick(TPS("Startirq"), rdp->dynticks_nmi_nesting, 0, rdtp->dynticks);
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WRITE_ONCE(rdp->dynticks_nmi_nesting, 0); /* Avoid store tearing. */
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if (irq)
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rcu_prepare_for_idle();
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@ -739,25 +741,27 @@ void rcu_irq_exit_irqson(void)
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*/
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static void rcu_eqs_exit(bool user)
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{
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struct rcu_data *rdp;
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struct rcu_dynticks *rdtp;
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long oldval;
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lockdep_assert_irqs_disabled();
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rdtp = this_cpu_ptr(&rcu_dynticks);
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oldval = rdtp->dynticks_nesting;
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rdp = this_cpu_ptr(&rcu_data);
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oldval = rdp->dynticks_nesting;
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WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && oldval < 0);
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if (oldval) {
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rdtp->dynticks_nesting++;
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rdp->dynticks_nesting++;
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return;
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}
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rcu_dynticks_task_exit();
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rcu_dynticks_eqs_exit();
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rcu_cleanup_after_idle();
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trace_rcu_dyntick(TPS("End"), rdtp->dynticks_nesting, 1, rdtp->dynticks);
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trace_rcu_dyntick(TPS("End"), rdp->dynticks_nesting, 1, rdtp->dynticks);
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WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) && !user && !is_idle_task(current));
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WRITE_ONCE(rdtp->dynticks_nesting, 1);
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WARN_ON_ONCE(rdtp->dynticks_nmi_nesting);
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WRITE_ONCE(rdtp->dynticks_nmi_nesting, DYNTICK_IRQ_NONIDLE);
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WRITE_ONCE(rdp->dynticks_nesting, 1);
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WARN_ON_ONCE(rdp->dynticks_nmi_nesting);
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WRITE_ONCE(rdp->dynticks_nmi_nesting, DYNTICK_IRQ_NONIDLE);
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}
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/**
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@ -799,7 +803,7 @@ void rcu_user_exit(void)
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* @irq: Is this call from rcu_irq_enter?
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*
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* If the CPU was idle from RCU's viewpoint, update rdtp->dynticks and
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* rdtp->dynticks_nmi_nesting to let the RCU grace-period handling know
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* rdp->dynticks_nmi_nesting to let the RCU grace-period handling know
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* that the CPU is active. This implementation permits nested NMIs, as
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* long as the nesting level does not overflow an int. (You will probably
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* run out of stack space first.)
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@ -809,11 +813,12 @@ void rcu_user_exit(void)
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*/
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static __always_inline void rcu_nmi_enter_common(bool irq)
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{
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struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
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struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
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struct rcu_dynticks __maybe_unused *rdtp = this_cpu_ptr(&rcu_dynticks);
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long incby = 2;
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/* Complain about underflow. */
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WARN_ON_ONCE(rdtp->dynticks_nmi_nesting < 0);
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WARN_ON_ONCE(rdp->dynticks_nmi_nesting < 0);
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/*
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* If idle from RCU viewpoint, atomically increment ->dynticks
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@ -836,10 +841,10 @@ static __always_inline void rcu_nmi_enter_common(bool irq)
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incby = 1;
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}
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trace_rcu_dyntick(incby == 1 ? TPS("Endirq") : TPS("++="),
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rdtp->dynticks_nmi_nesting,
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rdtp->dynticks_nmi_nesting + incby, rdtp->dynticks);
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WRITE_ONCE(rdtp->dynticks_nmi_nesting, /* Prevent store tearing. */
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rdtp->dynticks_nmi_nesting + incby);
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rdp->dynticks_nmi_nesting,
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rdp->dynticks_nmi_nesting + incby, rdtp->dynticks);
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WRITE_ONCE(rdp->dynticks_nmi_nesting, /* Prevent store tearing. */
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rdp->dynticks_nmi_nesting + incby);
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barrier();
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}
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@ -3194,7 +3199,7 @@ rcu_boot_init_percpu_data(int cpu)
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/* Set up local state, ensuring consistent view of global state. */
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rdp->grpmask = leaf_node_cpu_bit(rdp->mynode, cpu);
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rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
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WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != 1);
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WARN_ON_ONCE(rdp->dynticks_nesting != 1);
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WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp->dynticks)));
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rdp->rcu_ofl_gp_seq = rcu_state.gp_seq;
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rdp->rcu_ofl_gp_flags = RCU_GP_CLEANED;
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@ -3227,7 +3232,7 @@ int rcutree_prepare_cpu(unsigned int cpu)
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if (rcu_segcblist_empty(&rdp->cblist) && /* No early-boot CBs? */
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!init_nocb_callback_list(rdp))
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rcu_segcblist_init(&rdp->cblist); /* Re-enable callbacks. */
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rdp->dynticks->dynticks_nesting = 1; /* CPU not up, no tearing. */
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rdp->dynticks_nesting = 1; /* CPU not up, no tearing. */
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rcu_dynticks_eqs_online();
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raw_spin_unlock_rcu_node(rnp); /* irqs remain disabled. */
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@ -38,8 +38,6 @@
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* Dynticks per-CPU state.
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*/
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struct rcu_dynticks {
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long dynticks_nesting; /* Track process nesting level. */
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long dynticks_nmi_nesting; /* Track irq/NMI nesting level. */
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atomic_t dynticks; /* Even value for idle, else odd. */
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};
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@ -1831,7 +1831,7 @@ static void print_cpu_stall_info(int cpu)
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"!."[!delta],
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ticks_value, ticks_title,
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rcu_dynticks_snap(rdtp) & 0xfff,
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rdtp->dynticks_nesting, rdtp->dynticks_nmi_nesting,
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rdp->dynticks_nesting, rdp->dynticks_nmi_nesting,
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rdp->softirq_snap, kstat_softirqs_cpu(RCU_SOFTIRQ, cpu),
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READ_ONCE(rcu_state.n_force_qs) - rcu_state.n_force_qs_gpstart,
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fast_no_hz);
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