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Subject[PATCH 3/5] locking/qspinlock_stat: Separate out the PV specific stat counts
Date
Some of the statistics counts are for PV qspinlocks only and are not
applicable if PARAVIRT_SPINLOCKS aren't configured. So make those counts
dependent on the PARAVIRT_SPINLOCKS config option now.

Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/locking/qspinlock_stat.h | 129 +++++++++++++++++++++++++---------------
1 file changed, 81 insertions(+), 48 deletions(-)

diff --git a/kernel/locking/qspinlock_stat.h b/kernel/locking/qspinlock_stat.h
index 4f8ca8c..ad2e9f4 100644
--- a/kernel/locking/qspinlock_stat.h
+++ b/kernel/locking/qspinlock_stat.h
@@ -50,6 +50,7 @@
* There may be slight difference between pv_kick_wake and pv_kick_unlock.
*/
enum qlock_stats {
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
qstat_pv_hash_hops,
qstat_pv_kick_unlock,
qstat_pv_kick_wake,
@@ -61,6 +62,7 @@ enum qlock_stats {
qstat_pv_wait_early,
qstat_pv_wait_head,
qstat_pv_wait_node,
+#endif
qstat_lock_pending,
qstat_lock_slowpath,
qstat_lock_use_node2,
@@ -82,6 +84,7 @@ enum qlock_stats {
#include <linux/fs.h>

static const char * const qstat_names[qstat_num + 1] = {
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
[qstat_pv_hash_hops] = "pv_hash_hops",
[qstat_pv_kick_unlock] = "pv_kick_unlock",
[qstat_pv_kick_wake] = "pv_kick_wake",
@@ -93,6 +96,7 @@ enum qlock_stats {
[qstat_pv_wait_early] = "pv_wait_early",
[qstat_pv_wait_head] = "pv_wait_head",
[qstat_pv_wait_node] = "pv_wait_node",
+#endif
[qstat_lock_pending] = "lock_pending",
[qstat_lock_slowpath] = "lock_slowpath",
[qstat_lock_use_node2] = "lock_use_node2",
@@ -107,6 +111,20 @@ enum qlock_stats {
* Per-cpu counters
*/
static DEFINE_PER_CPU(unsigned long, qstats[qstat_num]);
+
+/*
+ * Increment the PV qspinlock statistical counters
+ */
+static inline void qstat_inc(enum qlock_stats stat, bool cond)
+{
+ if (cond)
+ this_cpu_inc(qstats[stat]);
+}
+
+#ifdef CONFIG_PARAVIRT_SPINLOCKS
+/*
+ * PV specific per-cpu counters
+ */
static DEFINE_PER_CPU(u64, pv_kick_time);

/*
@@ -181,6 +199,69 @@ static ssize_t qstat_read(struct file *file, char __user *user_buf,
}

/*
+ * PV hash hop count
+ */
+static inline void qstat_hop(int hopcnt)
+{
+ this_cpu_add(qstats[qstat_pv_hash_hops], hopcnt);
+}
+
+/*
+ * Replacement function for pv_kick()
+ */
+static inline void __pv_kick(int cpu)
+{
+ u64 start = sched_clock();
+
+ per_cpu(pv_kick_time, cpu) = start;
+ pv_kick(cpu);
+ this_cpu_add(qstats[qstat_pv_latency_kick], sched_clock() - start);
+}
+
+/*
+ * Replacement function for pv_wait()
+ */
+static inline void __pv_wait(u8 *ptr, u8 val)
+{
+ u64 *pkick_time = this_cpu_ptr(&pv_kick_time);
+
+ *pkick_time = 0;
+ pv_wait(ptr, val);
+ if (*pkick_time) {
+ this_cpu_add(qstats[qstat_pv_latency_wake],
+ sched_clock() - *pkick_time);
+ qstat_inc(qstat_pv_kick_wake, true);
+ }
+}
+
+#define pv_kick(c) __pv_kick(c)
+#define pv_wait(p, v) __pv_wait(p, v)
+
+#else /* CONFIG_PARAVIRT_SPINLOCKS */
+static ssize_t qstat_read(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[64];
+ int cpu, counter, len;
+ u64 stat = 0;
+
+ /*
+ * Get the counter ID stored in file->f_inode->i_private
+ */
+ counter = (long)file_inode(file)->i_private;
+
+ if (counter >= qstat_num)
+ return -EBADF;
+
+ for_each_possible_cpu(cpu)
+ stat += per_cpu(qstats[counter], cpu);
+ len = snprintf(buf, sizeof(buf) - 1, "%llu\n", stat);
+
+ return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+#endif /* CONFIG_PARAVIRT_SPINLOCKS */
+
+/*
* Function to handle write request
*
* When counter = reset_cnts, reset all the counter values.
@@ -253,54 +334,6 @@ static int __init init_qspinlock_stat(void)
}
fs_initcall(init_qspinlock_stat);

-/*
- * Increment the PV qspinlock statistical counters
- */
-static inline void qstat_inc(enum qlock_stats stat, bool cond)
-{
- if (cond)
- this_cpu_inc(qstats[stat]);
-}
-
-/*
- * PV hash hop count
- */
-static inline void qstat_hop(int hopcnt)
-{
- this_cpu_add(qstats[qstat_pv_hash_hops], hopcnt);
-}
-
-/*
- * Replacement function for pv_kick()
- */
-static inline void __pv_kick(int cpu)
-{
- u64 start = sched_clock();
-
- per_cpu(pv_kick_time, cpu) = start;
- pv_kick(cpu);
- this_cpu_add(qstats[qstat_pv_latency_kick], sched_clock() - start);
-}
-
-/*
- * Replacement function for pv_wait()
- */
-static inline void __pv_wait(u8 *ptr, u8 val)
-{
- u64 *pkick_time = this_cpu_ptr(&pv_kick_time);
-
- *pkick_time = 0;
- pv_wait(ptr, val);
- if (*pkick_time) {
- this_cpu_add(qstats[qstat_pv_latency_wake],
- sched_clock() - *pkick_time);
- qstat_inc(qstat_pv_kick_wake, true);
- }
-}
-
-#define pv_kick(c) __pv_kick(c)
-#define pv_wait(p, v) __pv_wait(p, v)
-
#else /* CONFIG_QUEUED_LOCK_STAT */

static inline void qstat_inc(enum qlock_stats stat, bool cond) { }
--
1.8.3.1
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