Commit-ID: 8aa670cdacc1820cb0597e4b4b413ef91ede2dd9
Gitweb: https://git.kernel.org/tip/8aa670cdacc1820cb0597e4b4b413ef91ede2dd9
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Sat, 28 Apr 2018 14:15:40 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Thu, 12 Jul 2018 14:27:53 -0700
rcu: Convert ->rcu_iw_gpnum to ->gp_seq
This commit switches the interrupt-disabled detection mechanism to
->gp_seq. This mechanism is used as part of RCU CPU stall warnings,
and detects cases where the stall is due to a CPU having interrupts
disabled.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 12 ++++++------
kernel/rcu/tree.h | 2 +-
kernel/rcu/tree_plugin.h | 2 +-
3 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 56445f4c09a8..2ddbd1cfb31a 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1099,8 +1099,8 @@ static void rcu_gpnum_ovf(struct rcu_node *rnp, struct rcu_data *rdp)
if (ULONG_CMP_LT(rcu_seq_current(&rdp->gp_seq) + ULONG_MAX / 4,
rnp->gp_seq))
WRITE_ONCE(rdp->gpwrap, true);
- if (ULONG_CMP_LT(rdp->rcu_iw_gpnum + ULONG_MAX / 4, rnp->gpnum))
- rdp->rcu_iw_gpnum = rnp->gpnum + ULONG_MAX / 4;
+ if (ULONG_CMP_LT(rdp->rcu_iw_gp_seq + ULONG_MAX / 4, rnp->gp_seq))
+ rdp->rcu_iw_gp_seq = rnp->gp_seq + ULONG_MAX / 4;
}
/*
@@ -1134,7 +1134,7 @@ static void rcu_iw_handler(struct irq_work *iwp)
rnp = rdp->mynode;
raw_spin_lock_rcu_node(rnp);
if (!WARN_ON_ONCE(!rdp->rcu_iw_pending)) {
- rdp->rcu_iw_gpnum = rnp->gpnum;
+ rdp->rcu_iw_gp_seq = rnp->gp_seq;
rdp->rcu_iw_pending = false;
}
raw_spin_unlock_rcu_node(rnp);
@@ -1231,11 +1231,11 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
if (jiffies - rdp->rsp->gp_start > rcu_jiffies_till_stall_check() / 2) {
resched_cpu(rdp->cpu);
if (IS_ENABLED(CONFIG_IRQ_WORK) &&
- !rdp->rcu_iw_pending && rdp->rcu_iw_gpnum != rnp->gpnum &&
+ !rdp->rcu_iw_pending && rdp->rcu_iw_gp_seq != rnp->gp_seq &&
(rnp->ffmask & rdp->grpmask)) {
init_irq_work(&rdp->rcu_iw, rcu_iw_handler);
rdp->rcu_iw_pending = true;
- rdp->rcu_iw_gpnum = rnp->gpnum;
+ rdp->rcu_iw_gp_seq = rnp->gp_seq;
irq_work_queue_on(&rdp->rcu_iw, rdp->cpu);
}
}
@@ -3575,7 +3575,7 @@ rcu_init_percpu_data(int cpu, struct rcu_state *rsp)
rdp->rcu_qs_ctr_snap = per_cpu(rcu_dynticks.rcu_qs_ctr, cpu);
rdp->core_needs_qs = false;
rdp->rcu_iw_pending = false;
- rdp->rcu_iw_gpnum = rnp->gpnum - 1;
+ rdp->rcu_iw_gp_seq = rnp->gp_seq - 1;
trace_rcu_grace_period(rsp->name, rdp->gpnum, TPS("cpuonl"));
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 50a28d1cf5a1..6d6cbc8b3a9c 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -286,7 +286,7 @@ struct rcu_data {
/* ->rcu_iw* fields protected by leaf rcu_node ->lock. */
struct irq_work rcu_iw; /* Check for non-irq activity. */
bool rcu_iw_pending; /* Is ->rcu_iw pending? */
- unsigned long rcu_iw_gpnum; /* ->gpnum associated with ->rcu_iw. */
+ unsigned long rcu_iw_gp_seq; /* ->gp_seq associated with ->rcu_iw. */
int cpu;
struct rcu_state *rsp;
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 5b10904669c5..bc32e1f434a6 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1763,7 +1763,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
ticks_value = rsp->gpnum - rdp->gpnum;
}
print_cpu_stall_fast_no_hz(fast_no_hz, cpu);
- delta = rdp->mynode->gpnum - rdp->rcu_iw_gpnum;
+ delta = rcu_seq_ctr(rdp->mynode->gp_seq - rdp->rcu_iw_gp_seq);
pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%ld softirq=%u/%u fqs=%ld %s\n",
cpu,
"O."[!!cpu_online(cpu)],
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|