[PATCH tip/core/rcu 09/17] rcu: Shrink ->dynticks_{nmi_,}nesting from long long to long

From: Paul E. McKenney
Date: Fri Dec 01 2017 - 14:38:47 EST


Because the ->dynticks_nesting field now only contains the process-based
nesting level instead of a value encoding both the process nesting level
and the irq "nesting" level, we no longer need a long long, even on
32-bit systems. This commit therefore changes both the ->dynticks_nesting
and ->dynticks_nmi_nesting fields to long.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
include/trace/events/rcu.h | 8 ++++----
kernel/rcu/rcu.h | 2 +-
kernel/rcu/tree.c | 6 +++---
kernel/rcu/tree.h | 4 ++--
kernel/rcu/tree_plugin.h | 2 +-
5 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 4674b21247f7..b0a48231ea0e 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -436,14 +436,14 @@ TRACE_EVENT(rcu_fqs,
*/
TRACE_EVENT(rcu_dyntick,

- TP_PROTO(const char *polarity, long long oldnesting, long long newnesting),
+ TP_PROTO(const char *polarity, long oldnesting, long newnesting),

TP_ARGS(polarity, oldnesting, newnesting),

TP_STRUCT__entry(
__field(const char *, polarity)
- __field(long long, oldnesting)
- __field(long long, newnesting)
+ __field(long, oldnesting)
+ __field(long, newnesting)
),

TP_fast_assign(
@@ -452,7 +452,7 @@ TRACE_EVENT(rcu_dyntick,
__entry->newnesting = newnesting;
),

- TP_printk("%s %llx %llx", __entry->polarity,
+ TP_printk("%s %lx %lx", __entry->polarity,
__entry->oldnesting, __entry->newnesting)
);

diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index afe0559d1867..6334f2c1abd0 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -31,7 +31,7 @@
#endif /* #else #ifdef CONFIG_RCU_TRACE */

/* Offset to allow for unmatched rcu_irq_{enter,exit}(). */
-#define DYNTICK_IRQ_NONIDLE ((INT_MAX / 2) + 1)
+#define DYNTICK_IRQ_NONIDLE ((LONG_MAX / 2) + 1)


/*
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index d069ba2d8412..92de3bacda07 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -946,7 +946,7 @@ void rcu_irq_exit_irqson(void)
* we really have exited idle, and must do the appropriate accounting.
* The caller must have disabled interrupts.
*/
-static void rcu_eqs_exit_common(long long newval, int user)
+static void rcu_eqs_exit_common(long newval, int user)
{
RCU_TRACE(struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);)

@@ -979,7 +979,7 @@ static void rcu_eqs_exit_common(long long newval, int user)
static void rcu_eqs_exit(bool user)
{
struct rcu_dynticks *rdtp;
- long long oldval;
+ long oldval;

lockdep_assert_irqs_disabled();
rdtp = this_cpu_ptr(&rcu_dynticks);
@@ -1043,7 +1043,7 @@ void rcu_user_exit(void)
void rcu_nmi_enter(void)
{
struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
- int incby = 2;
+ long incby = 2;

/* Complain about underflow. */
WARN_ON_ONCE(rdtp->dynticks_nmi_nesting < 0);
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index dbd7e3753bed..6488a3b0e729 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -38,8 +38,8 @@
* Dynticks per-CPU state.
*/
struct rcu_dynticks {
- long long dynticks_nesting; /* Track irq/process nesting level. */
- int dynticks_nmi_nesting; /* Track NMI nesting level. */
+ long dynticks_nesting; /* Track process nesting level. */
+ long dynticks_nmi_nesting; /* Track irq/NMI nesting level. */
atomic_t dynticks; /* Even value for idle, else odd. */
bool rcu_need_heavy_qs; /* GP old, need heavy quiescent state. */
unsigned long rcu_qs_ctr; /* Light universal quiescent state ctr. */
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index db85ca3975f1..e94e754464cd 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1687,7 +1687,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
}
print_cpu_stall_fast_no_hz(fast_no_hz, cpu);
delta = rdp->mynode->gpnum - rdp->rcu_iw_gpnum;
- pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n",
+ 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)],
"o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)],
--
2.5.2