From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 32/52] rcu: Remove rsp parameter from rcu_boot_init_percpu_data() and friends
Date: Wed, 29 Aug 2018 15:38:34 -0700 [thread overview]
Message-ID: <20180829223854.4055-32-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180829223830.GA1800@linux.vnet.ibm.com>
There now is only one rcu_state structure in a given build of
the Linux kernel, so there is no need to pass it as a parameter
to RCU's functions. This commit therefore removes the rsp
parameter from rcu_boot_init_percpu_data(), rcu_init_percpu_data(),
rcu_cleanup_dying_idle_cpu(), and rcu_migrate_callbacks(). While in
the neighborhood, line the last three into rcutree_prepare_cpu(),
rcu_report_dead() and rcutree_migrate_callbacks(), respectively.
This also gets rid of the for_each_rcu_flavor() calls that were in
those tree functions.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 102 ++++++++++++++++------------------------------
1 file changed, 35 insertions(+), 67 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8028936dc95d..3591633efc33 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3351,7 +3351,7 @@ static void rcu_init_new_rnp(struct rcu_node *rnp_leaf)
* Do boot-time initialization of a CPU's per-CPU RCU data.
*/
static void __init
-rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
+rcu_boot_init_percpu_data(int cpu)
{
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
@@ -3360,23 +3360,25 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->dynticks = &per_cpu(rcu_dynticks, cpu);
WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != 1);
WARN_ON_ONCE(rcu_dynticks_in_eqs(rcu_dynticks_snap(rdp->dynticks)));
- rdp->rcu_ofl_gp_seq = rsp->gp_seq;
+ rdp->rcu_ofl_gp_seq = rcu_state.gp_seq;
rdp->rcu_ofl_gp_flags = RCU_GP_CLEANED;
- rdp->rcu_onl_gp_seq = rsp->gp_seq;
+ rdp->rcu_onl_gp_seq = rcu_state.gp_seq;
rdp->rcu_onl_gp_flags = RCU_GP_CLEANED;
rdp->cpu = cpu;
- rdp->rsp = rsp;
+ rdp->rsp = &rcu_state;
rcu_boot_init_nocb_percpu_data(rdp);
}
/*
- * Initialize a CPU's per-CPU RCU data. Note that only one online or
+ * Invoked early in the CPU-online process, when pretty much all services
+ * are available. The incoming CPU is not present.
+ *
+ * Initializes a CPU's per-CPU RCU data. Note that only one online or
* offline event can be happening at a given time. Note also that we can
* accept some slop in the rsp->gp_seq access due to the fact that this
* CPU cannot possibly have any RCU callbacks in flight yet.
*/
-static void
-rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
+int rcutree_prepare_cpu(unsigned int cpu)
{
unsigned long flags;
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
@@ -3385,7 +3387,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
/* Set up local state, ensuring consistent view of global state. */
raw_spin_lock_irqsave_rcu_node(rnp, flags);
rdp->qlen_last_fqs_check = 0;
- rdp->n_force_qs_snap = rsp->n_force_qs;
+ rdp->n_force_qs_snap = rcu_state.n_force_qs;
rdp->blimit = blimit;
if (rcu_segcblist_empty(&rdp->cblist) && /* No early-boot CBs? */
!init_nocb_callback_list(rdp))
@@ -3409,21 +3411,8 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->core_needs_qs = false;
rdp->rcu_iw_pending = false;
rdp->rcu_iw_gp_seq = rnp->gp_seq - 1;
- trace_rcu_grace_period(rsp->name, rdp->gp_seq, TPS("cpuonl"));
+ trace_rcu_grace_period(rcu_state.name, rdp->gp_seq, TPS("cpuonl"));
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
-}
-
-/*
- * Invoked early in the CPU-online process, when pretty much all
- * services are available. The incoming CPU is not present.
- */
-int rcutree_prepare_cpu(unsigned int cpu)
-{
- struct rcu_state *rsp;
-
- for_each_rcu_flavor(rsp)
- rcu_init_percpu_data(cpu, rsp);
-
rcu_prepare_kthreads(cpu);
rcu_spawn_all_nocb_kthreads(cpu);
@@ -3547,23 +3536,32 @@ void rcu_cpu_starting(unsigned int cpu)
#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 ->qsmaskinitnext
- * bit masks.
+ * The outgoing function has no further need of RCU, so remove it from
+ * the rcu_node tree's ->qsmaskinitnext bit masks.
+ *
+ * Note that this function is special in that it is invoked directly
+ * from the outgoing CPU rather than from the cpuhp_step mechanism.
+ * This is because this function must be invoked at a precise location.
*/
-static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
+void rcu_report_dead(unsigned int cpu)
{
unsigned long flags;
unsigned long mask;
struct rcu_data *rdp = per_cpu_ptr(&rcu_data, cpu);
struct rcu_node *rnp = rdp->mynode; /* Outgoing CPU's rdp & rnp. */
+ /* QS for any half-done expedited RCU-sched GP. */
+ preempt_disable();
+ rcu_report_exp_rdp(&rcu_state, this_cpu_ptr(&rcu_data));
+ preempt_enable();
+ rcu_preempt_deferred_qs(current);
+
/* Remove outgoing CPU from mask in the leaf rcu_node structure. */
mask = rdp->grpmask;
- spin_lock(&rsp->ofl_lock);
+ spin_lock(&rcu_state.ofl_lock);
raw_spin_lock_irqsave_rcu_node(rnp, flags); /* Enforce GP memory-order guarantee. */
- rdp->rcu_ofl_gp_seq = READ_ONCE(rsp->gp_seq);
- rdp->rcu_ofl_gp_flags = READ_ONCE(rsp->gp_flags);
+ rdp->rcu_ofl_gp_seq = READ_ONCE(rcu_state.gp_seq);
+ rdp->rcu_ofl_gp_flags = READ_ONCE(rcu_state.gp_flags);
if (rnp->qsmask & mask) { /* RCU waiting on outgoing CPU? */
/* Report quiescent state -before- changing ->qsmaskinitnext! */
rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
@@ -3571,34 +3569,17 @@ static void rcu_cleanup_dying_idle_cpu(int cpu, struct rcu_state *rsp)
}
rnp->qsmaskinitnext &= ~mask;
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
- spin_unlock(&rsp->ofl_lock);
-}
-
-/*
- * The outgoing function has no further need of RCU, so remove it from
- * the list of CPUs that RCU must track.
- *
- * Note that this function is special in that it is invoked directly
- * from the outgoing CPU rather than from the cpuhp_step mechanism.
- * This is because this function must be invoked at a precise location.
- */
-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_state, this_cpu_ptr(&rcu_data));
- preempt_enable();
- rcu_preempt_deferred_qs(current);
- for_each_rcu_flavor(rsp)
- rcu_cleanup_dying_idle_cpu(cpu, rsp);
+ spin_unlock(&rcu_state.ofl_lock);
per_cpu(rcu_cpu_started, cpu) = 0;
}
-/* Migrate the dead CPU's callbacks to the current CPU. */
-static void rcu_migrate_callbacks(int cpu, struct rcu_state *rsp)
+/*
+ * The outgoing CPU has just passed through the dying-idle state, and we
+ * are being invoked from the CPU that was IPIed to continue the offline
+ * operation. Migrate the outgoing CPU's callbacks to the current CPU.
+ */
+void rcutree_migrate_callbacks(int cpu)
{
unsigned long flags;
struct rcu_data *my_rdp;
@@ -3631,19 +3612,6 @@ static void rcu_migrate_callbacks(int cpu, struct rcu_state *rsp)
cpu, rcu_segcblist_n_cbs(&rdp->cblist),
rcu_segcblist_first_cb(&rdp->cblist));
}
-
-/*
- * The outgoing CPU has just passed through the dying-idle state,
- * and we are being invoked from the CPU that was IPIed to continue the
- * offline operation. We need to migrate the outgoing CPU's callbacks.
- */
-void rcutree_migrate_callbacks(int cpu)
-{
- struct rcu_state *rsp;
-
- for_each_rcu_flavor(rsp)
- rcu_migrate_callbacks(cpu, rsp);
-}
#endif
/*
@@ -3813,7 +3781,7 @@ static void __init rcu_init_one(struct rcu_state *rsp)
while (i > rnp->grphi)
rnp++;
per_cpu_ptr(&rcu_data, i)->mynode = rnp;
- rcu_boot_init_percpu_data(i, rsp);
+ rcu_boot_init_percpu_data(i);
}
list_add(&rsp->flavors, &rcu_struct_flavors);
}
--
2.17.1
next prev parent reply other threads:[~2018-08-29 22:42 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-29 22:38 [PATCH tip/core/rcu 0/52] Remove rcu_state pointers for v4.20/v5.0 Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 01/52] rcu: Remove rsp parameter from rcu_report_qs_rnp() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 02/52] rcu: Remove rsp parameter from rcu_report_qs_rsp() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 03/52] rcu: Remove rsp parameter from rcu_report_unblock_qs_rnp() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 04/52] rcu: Remove rsp parameter from rcu_report_qs_rdp() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 05/52] rcu: Remove rsp parameter from rcu_gp_in_progress() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 06/52] rcu: Remove rsp parameter from rcu_get_root() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 07/52] rcu: Remove rsp parameter from record_gp_stall_check_time() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 08/52] rcu: Remove rsp parameter from rcu_check_gp_kthread_starvation() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 09/52] rcu: Remove rsp parameter from rcu_dump_cpu_stacks() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 10/52] rcu: Remove rsp parameter from rcu_stall_kick_kthreads() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 11/52] rcu: Remove rsp parameter from print_other_cpu_stall() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 12/52] rcu: Remove rsp parameter from print_cpu_stall() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 13/52] rcu: Remove rsp parameter from check_cpu_stall() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 14/52] rcu: Remove rsp parameter from rcu_future_gp_cleanup() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 15/52] rcu: Remove rsp parameter from rcu_gp_kthread_wake() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 16/52] rcu: Remove rsp parameter from rcu_accelerate_cbs() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 17/52] rcu: Remove rsp parameter from rcu_accelerate_cbs_unlocked() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 18/52] rcu: Remove rsp parameter from rcu_advance_cbs() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 19/52] rcu: Remove rsp parameter from __note_gp_changes() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 20/52] rcu: Remove rsp parameter from note_gp_changes() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 21/52] rcu: Remove rsp parameter from rcu_gp_slow() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 22/52] rcu: Remove rsp parameter from rcu_gp_kthread() and friends Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 23/52] rcu: Remove rsp parameter from rcu_check_quiescent_state() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 24/52] rcu: Remove rsp parameter from CPU hotplug functions Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 25/52] rcu: Remove rsp parameter from rcu_do_batch() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 26/52] rcu: Remove rsp parameter from force-quiescent-state functions Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 27/52] rcu: Remove rsp parameter from rcu_check_gp_start_stall() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 28/52] rcu: Remove rsp parameter from __rcu_process_callbacks() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 29/52] rcu: Remove rsp parameter from __call_rcu() and friend Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 30/52] rcu: Remove rsp parameter from __rcu_pending() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 31/52] rcu: Remove rsp parameter from _rcu_barrier() and friends Paul E. McKenney
2018-08-29 22:38 ` Paul E. McKenney [this message]
2018-08-29 22:38 ` [PATCH tip/core/rcu 33/52] rcu: Remove rsp parameter from rcu_init_one() " Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 34/52] rcu: Remove rsp parameter from rcu_print_detail_task_stall() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 35/52] rcu: Remove rsp parameter from dump_blkd_tasks() and friend Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 36/52] rcu: Remove rsp parameter from rcu_spawn_one_boost_kthread() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 37/52] rcu: Remove rsp parameter from print_cpu_stall_info() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 38/52] rcu: Remove rsp parameter from no-CBs CPU functions Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 39/52] rcu: Remove rsp parameter from expedited grace-period functions Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 40/52] rcu: Remove rsp parameter from rcu_node tree accessor macros Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 41/52] rcu: Remove rcu_data structure's ->rsp field Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 42/52] rcu: Remove last non-flavor-traversal rsp local variable from tree_plugin.h Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 43/52] rcu: Remove for_each_rcu_flavor() flavor-traversal macro Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 44/52] rcu: Simplify rcutorture_get_gp_data() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 45/52] rcu: Restructure rcu_check_gp_kthread_starvation() Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 46/52] rcu: Eliminate stall-warning use of rsp Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 47/52] rcu: Eliminate grace-period management code " Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 48/52] rcu: Eliminate callback-invocation/invocation " Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 49/52] rcu: Eliminate quiescent-state and grace-period-nonstart " Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 50/52] rcu: Eliminate RCU-barrier " Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 51/52] rcu: Eliminate initialization-time " Paul E. McKenney
2018-08-29 22:38 ` [PATCH tip/core/rcu 52/52] rcu: Fix typo in force_qs_rnp()'s parameter's parameter Paul E. McKenney
2018-08-30 2:00 ` [PATCH tip/core/rcu 0/52] Remove rcu_state pointers for v4.20/v5.0 Steven Rostedt
2018-08-30 3:22 ` Paul E. McKenney
2018-08-30 4:10 ` Paul E. McKenney
2018-08-30 4:20 ` Josh Triplett
2018-08-30 15:42 ` Steven Rostedt
2018-08-30 15:44 ` Steven Rostedt
2018-08-30 17:10 ` Paul E. McKenney
2018-08-30 17:40 ` Steven Rostedt
2018-08-30 18:26 ` Paul E. McKenney
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