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-rw-r--r--kernel/latencytop.c45
1 files changed, 31 insertions, 14 deletions
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index 8d1c15832e55..781249098cb6 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -55,6 +55,7 @@
#include <linux/sched/stat.h>
#include <linux/list.h>
#include <linux/stacktrace.h>
+#include <linux/sysctl.h>
static DEFINE_RAW_SPINLOCK(latency_lock);
@@ -63,6 +64,31 @@ static struct latency_record latency_record[MAXLR];
int latencytop_enabled;
+#ifdef CONFIG_SYSCTL
+static int sysctl_latencytop(struct ctl_table *table, int write, void *buffer,
+ size_t *lenp, loff_t *ppos)
+{
+ int err;
+
+ err = proc_dointvec(table, write, buffer, lenp, ppos);
+ if (latencytop_enabled)
+ force_schedstat_enabled();
+
+ return err;
+}
+
+static struct ctl_table latencytop_sysctl[] = {
+ {
+ .procname = "latencytop",
+ .data = &latencytop_enabled,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = sysctl_latencytop,
+ },
+ {}
+};
+#endif
+
void clear_tsk_latency_tracing(struct task_struct *p)
{
unsigned long flags;
@@ -86,7 +112,7 @@ static void __sched
account_global_scheduler_latency(struct task_struct *tsk,
struct latency_record *lat)
{
- int firstnonnull = MAXLR + 1;
+ int firstnonnull = MAXLR;
int i;
/* skip kernel threads for now */
@@ -124,7 +150,7 @@ account_global_scheduler_latency(struct task_struct *tsk,
}
i = firstnonnull;
- if (i >= MAXLR - 1)
+ if (i >= MAXLR)
return;
/* Allocted a new one: */
@@ -266,18 +292,9 @@ static const struct proc_ops lstats_proc_ops = {
static int __init init_lstats_procfs(void)
{
proc_create("latency_stats", 0644, NULL, &lstats_proc_ops);
+#ifdef CONFIG_SYSCTL
+ register_sysctl_init("kernel", latencytop_sysctl);
+#endif
return 0;
}
-
-int sysctl_latencytop(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp, loff_t *ppos)
-{
- int err;
-
- err = proc_dointvec(table, write, buffer, lenp, ppos);
- if (latencytop_enabled)
- force_schedstat_enabled();
-
- return err;
-}
device_initcall(init_lstats_procfs);