scftorture: Count single_rpc offline failures in statistics outputgrafted

scf_torture_stats_print() aggregates each invoker thread's counters
into a local scf_statistics structure before printing, but the
n_single_rpc_ofl field is missing from the aggregation loop.  As a
result, the "single_rpc_ofl" value printed in the statistics line is
always zero, even when smp_call_function_single() invocations for the
RPC test have failed due to offline CPUs and been counted by the
invoker threads.

Add the missing accumulation so that the printed value reflects the
actual counts.

Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

1 files changed, 147 insertions, 0 deletions

diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
new file mode 100644
index 000000000..75b8f4601
--- /dev/null
+++ b/include/asm-generic/qrwlock.h
@@ -0,0 +1,147 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Queue read/write lock
+ *
+ * These use generic atomic and locking routines, but depend on a fair spinlock
+ * implementation in order to be fair themselves.  The implementation in
+ * asm-generic/spinlock.h meets these requirements.
+ *
+ * (C) Copyright 2013-2014 Hewlett-Packard Development Company, L.P.
+ *
+ * Authors: Waiman Long <waiman.long@hp.com>
+ */
+#ifndef __ASM_GENERIC_QRWLOCK_H
+#define __ASM_GENERIC_QRWLOCK_H
+
+#include <linux/atomic.h>
+#include <asm/barrier.h>
+#include <asm/processor.h>
+
+#include <asm-generic/qrwlock_types.h>
+
+/* Must be included from asm/spinlock.h after defining arch_spin_is_locked.  */
+
+/*
+ * Writer states & reader shift and bias.
+ */
+#define	_QW_WAITING	0x100		/* A writer is waiting	   */
+#define	_QW_LOCKED	0x0ff		/* A writer holds the lock */
+#define	_QW_WMASK	0x1ff		/* Writer mask		   */
+#define	_QR_SHIFT	9		/* Reader count shift	   */
+#define _QR_BIAS	(1U << _QR_SHIFT)
+
+/*
+ * External function declarations
+ */
+extern void queued_read_lock_slowpath(struct qrwlock *lock);
+extern void queued_write_lock_slowpath(struct qrwlock *lock);
+
+/**
+ * queued_read_trylock - try to acquire read lock of a queued rwlock
+ * @lock : Pointer to queued rwlock structure
+ * Return: 1 if lock acquired, 0 if failed
+ */
+static inline int queued_read_trylock(struct qrwlock *lock)
+{
+	int cnts;
+
+	cnts = atomic_read(&lock->cnts);
+	if (likely(!(cnts & _QW_WMASK))) {
+		cnts = (u32)atomic_add_return_acquire(_QR_BIAS, &lock->cnts);
+		if (likely(!(cnts & _QW_WMASK)))
+			return 1;
+		atomic_sub(_QR_BIAS, &lock->cnts);
+	}
+	return 0;
+}
+
+/**
+ * queued_write_trylock - try to acquire write lock of a queued rwlock
+ * @lock : Pointer to queued rwlock structure
+ * Return: 1 if lock acquired, 0 if failed
+ */
+static inline int queued_write_trylock(struct qrwlock *lock)
+{
+	int cnts;
+
+	cnts = atomic_read(&lock->cnts);
+	if (unlikely(cnts))
+		return 0;
+
+	return likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts,
+				_QW_LOCKED));
+}
+/**
+ * queued_read_lock - acquire read lock of a queued rwlock
+ * @lock: Pointer to queued rwlock structure
+ */
+static inline void queued_read_lock(struct qrwlock *lock)
+{
+	int cnts;
+
+	cnts = atomic_add_return_acquire(_QR_BIAS, &lock->cnts);
+	if (likely(!(cnts & _QW_WMASK)))
+		return;
+
+	/* The slowpath will decrement the reader count, if necessary. */
+	queued_read_lock_slowpath(lock);
+}
+
+/**
+ * queued_write_lock - acquire write lock of a queued rwlock
+ * @lock : Pointer to queued rwlock structure
+ */
+static inline void queued_write_lock(struct qrwlock *lock)
+{
+	int cnts = 0;
+	/* Optimize for the unfair lock case where the fair flag is 0. */
+	if (likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts, _QW_LOCKED)))
+		return;
+
+	queued_write_lock_slowpath(lock);
+}
+
+/**
+ * queued_read_unlock - release read lock of a queued rwlock
+ * @lock : Pointer to queued rwlock structure
+ */
+static inline void queued_read_unlock(struct qrwlock *lock)
+{
+	/*
+	 * Atomically decrement the reader count
+	 */
+	(void)atomic_sub_return_release(_QR_BIAS, &lock->cnts);
+}
+
+/**
+ * queued_write_unlock - release write lock of a queued rwlock
+ * @lock : Pointer to queued rwlock structure
+ */
+static inline void queued_write_unlock(struct qrwlock *lock)
+{
+	smp_store_release(&lock->wlocked, 0);
+}
+
+/**
+ * queued_rwlock_is_contended - check if the lock is contended
+ * @lock : Pointer to queued rwlock structure
+ * Return: 1 if lock contended, 0 otherwise
+ */
+static inline int queued_rwlock_is_contended(struct qrwlock *lock)
+{
+	return arch_spin_is_locked(&lock->wait_lock);
+}
+
+/*
+ * Remapping rwlock architecture specific functions to the corresponding
+ * queued rwlock functions.
+ */
+#define arch_read_lock(l)		queued_read_lock(l)
+#define arch_write_lock(l)		queued_write_lock(l)
+#define arch_read_trylock(l)		queued_read_trylock(l)
+#define arch_write_trylock(l)		queued_write_trylock(l)
+#define arch_read_unlock(l)		queued_read_unlock(l)
+#define arch_write_unlock(l)		queued_write_unlock(l)
+#define arch_rwlock_is_contended(l)	queued_rwlock_is_contended(l)
+
+#endif /* __ASM_GENERIC_QRWLOCK_H */