rcu: Add rcu_normal kernel parameter to suppress expediting

[linux-2.6-microblaze.git] / kernel / ksysfs.c

diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index e83b264..b4e2fa5 100644 (file)
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -20,7 +20,7 @@
 #include <linux/capability.h>
 #include <linux/compiler.h>
 
-#include <linux/rcupdate.h>    /* rcu_expedited */
+#include <linux/rcupdate.h>    /* rcu_expedited and rcu_normal */
 
 #define KERNEL_ATTR_RO(_name) \
 static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
@@ -148,7 +148,7 @@ int rcu_expedited;
 static ssize_t rcu_expedited_show(struct kobject *kobj,
                                  struct kobj_attribute *attr, char *buf)
 {
-       return sprintf(buf, "%d\n", rcu_expedited);
+       return sprintf(buf, "%d\n", READ_ONCE(rcu_expedited));
 }
 static ssize_t rcu_expedited_store(struct kobject *kobj,
                                   struct kobj_attribute *attr,
@@ -161,6 +161,23 @@ static ssize_t rcu_expedited_store(struct kobject *kobj,
 }
 KERNEL_ATTR_RW(rcu_expedited);
 
+int rcu_normal;
+static ssize_t rcu_normal_show(struct kobject *kobj,
+                              struct kobj_attribute *attr, char *buf)
+{
+       return sprintf(buf, "%d\n", READ_ONCE(rcu_normal));
+}
+static ssize_t rcu_normal_store(struct kobject *kobj,
+                               struct kobj_attribute *attr,
+                               const char *buf, size_t count)
+{
+       if (kstrtoint(buf, 0, &rcu_normal))
+               return -EINVAL;
+
+       return count;
+}
+KERNEL_ATTR_RW(rcu_normal);
+
 /*
  * Make /sys/kernel/notes give the raw contents of our kernel .notes section.
  */
@@ -203,6 +220,7 @@ static struct attribute * kernel_attrs[] = {
        &vmcoreinfo_attr.attr,
 #endif
        &rcu_expedited_attr.attr,
+       &rcu_normal_attr.attr,
        NULL
 };