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 49/52] rcu: Eliminate quiescent-state and grace-period-nonstart use of rsp
Date: Wed, 29 Aug 2018 15:38:51 -0700 [thread overview]
Message-ID: <20180829223854.4055-49-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180829223830.GA1800@linux.vnet.ibm.com>
Now that there is only one rcu_state structure, there is less point in
maintaining a pointer to it. This commit therefore replaces rsp with
&rcu_state in rcu_report_qs_rnp(), force_quiescent_state(), and
rcu_check_gp_start_stall().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 32 +++++++++++++++-----------------
1 file changed, 15 insertions(+), 17 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index e6f0d8b6bde3..962b75c9722a 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -2197,7 +2197,6 @@ static void rcu_report_qs_rnp(unsigned long mask, struct rcu_node *rnp,
{
unsigned long oldmask = 0;
struct rcu_node *rnp_c;
- struct rcu_state __maybe_unused *rsp = &rcu_state;
raw_lockdep_assert_held_rcu_node(rnp);
@@ -2216,7 +2215,7 @@ static void rcu_report_qs_rnp(unsigned long mask, struct rcu_node *rnp,
WARN_ON_ONCE(!rcu_is_leaf_node(rnp) &&
rcu_preempt_blocked_readers_cgp(rnp));
rnp->qsmask &= ~mask;
- trace_rcu_quiescent_state_report(rsp->name, rnp->gp_seq,
+ trace_rcu_quiescent_state_report(rcu_state.name, rnp->gp_seq,
mask, rnp->qsmask, rnp->level,
rnp->grplo, rnp->grphi,
!!rnp->gp_tasks);
@@ -2623,12 +2622,11 @@ static void force_quiescent_state(void)
bool ret;
struct rcu_node *rnp;
struct rcu_node *rnp_old = NULL;
- struct rcu_state *rsp = &rcu_state;
/* Funnel through hierarchy to reduce memory contention. */
rnp = __this_cpu_read(rcu_data.mynode);
for (; rnp != NULL; rnp = rnp->parent) {
- ret = (READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) ||
+ ret = (READ_ONCE(rcu_state.gp_flags) & RCU_GP_FLAG_FQS) ||
!raw_spin_trylock(&rnp->fqslock);
if (rnp_old != NULL)
raw_spin_unlock(&rnp_old->fqslock);
@@ -2641,11 +2639,12 @@ static void force_quiescent_state(void)
/* Reached the root of the rcu_node tree, acquire lock. */
raw_spin_lock_irqsave_rcu_node(rnp_old, flags);
raw_spin_unlock(&rnp_old->fqslock);
- if (READ_ONCE(rsp->gp_flags) & RCU_GP_FLAG_FQS) {
+ if (READ_ONCE(rcu_state.gp_flags) & RCU_GP_FLAG_FQS) {
raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
return; /* Someone beat us to it. */
}
- WRITE_ONCE(rsp->gp_flags, READ_ONCE(rsp->gp_flags) | RCU_GP_FLAG_FQS);
+ WRITE_ONCE(rcu_state.gp_flags,
+ READ_ONCE(rcu_state.gp_flags) | RCU_GP_FLAG_FQS);
raw_spin_unlock_irqrestore_rcu_node(rnp_old, flags);
rcu_gp_kthread_wake();
}
@@ -2661,15 +2660,14 @@ rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp)
unsigned long flags;
unsigned long j;
struct rcu_node *rnp_root = rcu_get_root();
- struct rcu_state *rsp = &rcu_state;
static atomic_t warned = ATOMIC_INIT(0);
if (!IS_ENABLED(CONFIG_PROVE_RCU) || rcu_gp_in_progress() ||
ULONG_CMP_GE(rnp_root->gp_seq, rnp_root->gp_seq_needed))
return;
j = jiffies; /* Expensive access, and in common case don't get here. */
- if (time_before(j, READ_ONCE(rsp->gp_req_activity) + gpssdelay) ||
- time_before(j, READ_ONCE(rsp->gp_activity) + gpssdelay) ||
+ if (time_before(j, READ_ONCE(rcu_state.gp_req_activity) + gpssdelay) ||
+ time_before(j, READ_ONCE(rcu_state.gp_activity) + gpssdelay) ||
atomic_read(&warned))
return;
@@ -2677,8 +2675,8 @@ rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp)
j = jiffies;
if (rcu_gp_in_progress() ||
ULONG_CMP_GE(rnp_root->gp_seq, rnp_root->gp_seq_needed) ||
- time_before(j, READ_ONCE(rsp->gp_req_activity) + gpssdelay) ||
- time_before(j, READ_ONCE(rsp->gp_activity) + gpssdelay) ||
+ time_before(j, READ_ONCE(rcu_state.gp_req_activity) + gpssdelay) ||
+ time_before(j, READ_ONCE(rcu_state.gp_activity) + gpssdelay) ||
atomic_read(&warned)) {
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
@@ -2690,19 +2688,19 @@ rcu_check_gp_start_stall(struct rcu_node *rnp, struct rcu_data *rdp)
j = jiffies;
if (rcu_gp_in_progress() ||
ULONG_CMP_GE(rnp_root->gp_seq, rnp_root->gp_seq_needed) ||
- time_before(j, rsp->gp_req_activity + gpssdelay) ||
- time_before(j, rsp->gp_activity + gpssdelay) ||
+ time_before(j, rcu_state.gp_req_activity + gpssdelay) ||
+ time_before(j, rcu_state.gp_activity + gpssdelay) ||
atomic_xchg(&warned, 1)) {
raw_spin_unlock_rcu_node(rnp_root); /* irqs remain disabled. */
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
return;
}
pr_alert("%s: g%ld->%ld gar:%lu ga:%lu f%#x gs:%d %s->state:%#lx\n",
- __func__, (long)READ_ONCE(rsp->gp_seq),
+ __func__, (long)READ_ONCE(rcu_state.gp_seq),
(long)READ_ONCE(rnp_root->gp_seq_needed),
- j - rsp->gp_req_activity, j - rsp->gp_activity,
- rsp->gp_flags, rsp->gp_state, rsp->name,
- rsp->gp_kthread ? rsp->gp_kthread->state : 0x1ffffL);
+ j - rcu_state.gp_req_activity, j - rcu_state.gp_activity,
+ rcu_state.gp_flags, rcu_state.gp_state, rcu_state.name,
+ rcu_state.gp_kthread ? rcu_state.gp_kthread->state : 0x1ffffL);
WARN_ON(1);
if (rnp_root != rnp)
raw_spin_unlock_rcu_node(rnp_root);
--
2.17.1
next prev parent reply other threads:[~2018-08-29 22:39 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 ` [PATCH tip/core/rcu 32/52] rcu: Remove rsp parameter from rcu_boot_init_percpu_data() " Paul E. McKenney
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 ` Paul E. McKenney [this message]
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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