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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-08-20 20:26:14 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2020-08-25 03:40:28 +0200 |
| commit | cfeac3977ab4b6222a01f79997739d2367a8cc94 (patch) | |
| tree | 707963754755696b24aa3c0da8fff15bd5e1910a | |
| parent | rcu: Report QS for outermost PREEMPT=n rcu_read_unlock() for strict GPs (diff) | |
| download | linux-cfeac3977ab4b6222a01f79997739d2367a8cc94.tar.xz linux-cfeac3977ab4b6222a01f79997739d2367a8cc94.zip | |
rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp()
The "cpu" parameter to rcu_report_qs_rdp() is not used, with rdp->cpu
being used instead. Furtheremore, every call to rcu_report_qs_rdp()
invokes it on rdp->cpu. This commit therefore removes this unused "cpu"
parameter and converts a check of rdp->cpu against smp_processor_id()
to a WARN_ON_ONCE().
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | kernel/rcu/tree.c | 8 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 4 |
2 files changed, 6 insertions, 6 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a295cadf7c2f..c6127651efc6 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2240,7 +2240,7 @@ rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) * structure. This must be called from the specified CPU. */ static void -rcu_report_qs_rdp(int cpu, struct rcu_data *rdp) +rcu_report_qs_rdp(struct rcu_data *rdp) { unsigned long flags; unsigned long mask; @@ -2249,6 +2249,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_data *rdp) rcu_segcblist_is_offloaded(&rdp->cblist); struct rcu_node *rnp; + WARN_ON_ONCE(rdp->cpu != smp_processor_id()); rnp = rdp->mynode; raw_spin_lock_irqsave_rcu_node(rnp, flags); if (rdp->cpu_no_qs.b.norm || rdp->gp_seq != rnp->gp_seq || @@ -2265,8 +2266,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_data *rdp) return; } mask = rdp->grpmask; - if (rdp->cpu == smp_processor_id()) - rdp->core_needs_qs = false; + rdp->core_needs_qs = false; if ((rnp->qsmask & mask) == 0) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } else { @@ -2315,7 +2315,7 @@ rcu_check_quiescent_state(struct rcu_data *rdp) * Tell RCU we are done (but rcu_report_qs_rdp() will be the * judge of that). */ - rcu_report_qs_rdp(rdp->cpu, rdp); + rcu_report_qs_rdp(rdp); } /* diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 25a676dff5de..ca31be019f55 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -461,7 +461,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) t->rcu_read_unlock_special.s = 0; if (special.b.need_qs) { if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD)) { - rcu_report_qs_rdp(rdp->cpu, rdp); + rcu_report_qs_rdp(rdp); udelay(rcu_unlock_delay); } else { rcu_qs(); @@ -791,7 +791,7 @@ void rcu_read_unlock_strict(void) irqs_disabled() || preempt_count() || !rcu_state.gp_kthread) return; rdp = this_cpu_ptr(&rcu_data); - rcu_report_qs_rdp(rdp->cpu, rdp); + rcu_report_qs_rdp(rdp); udelay(rcu_unlock_delay); } EXPORT_SYMBOL_GPL(rcu_read_unlock_strict); |