Merge branch 'core' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core

10 files changed, 134 insertions, 449 deletions

diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 55addc85eaa7..6cc6521881aa 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -123,6 +123,12 @@ armpmu_get_max_events(void)
 }
 EXPORT_SYMBOL_GPL(armpmu_get_max_events);
 
+int perf_num_counters(void)
+{
+        return armpmu_get_max_events();
+}
+EXPORT_SYMBOL_GPL(perf_num_counters);
+
 #define HW_OP_UNSUPPORTED               0xFFFF
 
 #define C(_x) \
diff --git a/arch/arm/oprofile/Makefile b/arch/arm/oprofile/Makefile
index e666eafed152..b2215c61cdf0 100644
--- a/arch/arm/oprofile/Makefile
+++ b/arch/arm/oprofile/Makefile
@@ -6,4 +6,8 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
                 oprofilefs.o oprofile_stats.o \
                 timer_int.o )
 
+ifeq ($(CONFIG_HW_PERF_EVENTS),y)
+DRIVER_OBJS += $(addprefix ../../../drivers/oprofile/, oprofile_perf.o)
+endif
+
 oprofile-y                              := $(DRIVER_OBJS) common.o
diff --git a/arch/arm/oprofile/common.c b/arch/arm/oprofile/common.c
index d1fb5b2f5218..8aa974491dfc 100644
--- a/arch/arm/oprofile/common.c
+++ b/arch/arm/oprofile/common.c
@@ -25,139 +25,10 @@
 #include <asm/ptrace.h>
 
 #ifdef CONFIG_HW_PERF_EVENTS
-/*
- * Per performance monitor configuration as set via oprofilefs.
- */
-struct op_counter_config {
-        unsigned long count;
-        unsigned long enabled;
-        unsigned long event;
-        unsigned long unit_mask;
-        unsigned long kernel;
-        unsigned long user;
-        struct perf_event_attr attr;
-};
-
-static int op_arm_enabled;
-static DEFINE_MUTEX(op_arm_mutex);
-
-static struct op_counter_config *counter_config;
-static struct perf_event **perf_events[nr_cpumask_bits];
-static int perf_num_counters;
-
-/*
- * Overflow callback for oprofile.
- */
-static void op_overflow_handler(struct perf_event *event, int unused,
-                        struct perf_sample_data *data, struct pt_regs *regs)
+char *op_name_from_perf_id(void)
 {
-        int id;
-        u32 cpu = smp_processor_id();
-
-        for (id = 0; id < perf_num_counters; ++id)
-                if (perf_events[cpu][id] == event)
-                        break;
-
-        if (id != perf_num_counters)
-                oprofile_add_sample(regs, id);
-        else
-                pr_warning("oprofile: ignoring spurious overflow "
-                                "on cpu %u\n", cpu);
-}
-
-/*
- * Called by op_arm_setup to create perf attributes to mirror the oprofile
- * settings in counter_config. Attributes are created as `pinned' events and
- * so are permanently scheduled on the PMU.
- */
-static void op_perf_setup(void)
-{
-        int i;
-        u32 size = sizeof(struct perf_event_attr);
-        struct perf_event_attr *attr;
-
-        for (i = 0; i < perf_num_counters; ++i) {
-                attr = &counter_config[i].attr;
-                memset(attr, 0, size);
-                attr->type              = PERF_TYPE_RAW;
-                attr->size              = size;
-                attr->config            = counter_config[i].event;
-                attr->sample_period     = counter_config[i].count;
-                attr->pinned            = 1;
-        }
-}
-
-static int op_create_counter(int cpu, int event)
-{
-        int ret = 0;
-        struct perf_event *pevent;
-
-        if (!counter_config[event].enabled || (perf_events[cpu][event] != NULL))
-                return ret;
-
-        pevent = perf_event_create_kernel_counter(&counter_config[event].attr,
-                                                  cpu, NULL,
-                                                  op_overflow_handler);
-
-        if (IS_ERR(pevent)) {
-                ret = PTR_ERR(pevent);
-        } else if (pevent->state != PERF_EVENT_STATE_ACTIVE) {
-                perf_event_release_kernel(pevent);
-                pr_warning("oprofile: failed to enable event %d "
-                                "on CPU %d\n", event, cpu);
-                ret = -EBUSY;
-        } else {
-                perf_events[cpu][event] = pevent;
-        }
-
-        return ret;
-}
+        enum arm_perf_pmu_ids id = armpmu_get_pmu_id();
 
-static void op_destroy_counter(int cpu, int event)
-{
-        struct perf_event *pevent = perf_events[cpu][event];
-
-        if (pevent) {
-                perf_event_release_kernel(pevent);
-                perf_events[cpu][event] = NULL;
-        }
-}
-
-/*
- * Called by op_arm_start to create active perf events based on the
- * perviously configured attributes.
- */
-static int op_perf_start(void)
-{
-        int cpu, event, ret = 0;
-
-        for_each_online_cpu(cpu) {
-                for (event = 0; event < perf_num_counters; ++event) {
-                        ret = op_create_counter(cpu, event);
-                        if (ret)
-                                goto out;
-                }
-        }
-
-out:
-        return ret;
-}
-
-/*
- * Called by op_arm_stop at the end of a profiling run.
- */
-static void op_perf_stop(void)
-{
-        int cpu, event;
-
-        for_each_online_cpu(cpu)
-                for (event = 0; event < perf_num_counters; ++event)
-                        op_destroy_counter(cpu, event);
-}
-
-
-static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
-{
         switch (id) {
         case ARM_PERF_PMU_ID_XSCALE1:
                 return "arm/xscale1";
@@ -176,116 +47,6 @@ static char *op_name_from_perf_id(enum arm_perf_pmu_ids id)
         }
 }
 
-static int op_arm_create_files(struct super_block *sb, struct dentry *root)
-{
-        unsigned int i;
-
-        for (i = 0; i < perf_num_counters; i++) {
-                struct dentry *dir;
-                char buf[4];
-
-                snprintf(buf, sizeof buf, "%d", i);
-                dir = oprofilefs_mkdir(sb, root, buf);
-                oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
-                oprofilefs_create_ulong(sb, dir, "event", &counter_config[i].event);
-                oprofilefs_create_ulong(sb, dir, "count", &counter_config[i].count);
-                oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
-                oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
-                oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
-        }
-
-        return 0;
-}
-
-static int op_arm_setup(void)
-{
-        spin_lock(&oprofilefs_lock);
-        op_perf_setup();
-        spin_unlock(&oprofilefs_lock);
-        return 0;
-}
-
-static int op_arm_start(void)
-{
-        int ret = -EBUSY;
-
-        mutex_lock(&op_arm_mutex);
-        if (!op_arm_enabled) {
-                ret = 0;
-                op_perf_start();
-                op_arm_enabled = 1;
-        }
-        mutex_unlock(&op_arm_mutex);
-        return ret;
-}
-
-static void op_arm_stop(void)
-{
-        mutex_lock(&op_arm_mutex);
-        if (op_arm_enabled)
-                op_perf_stop();
-        op_arm_enabled = 0;
-        mutex_unlock(&op_arm_mutex);
-}
-
-#ifdef CONFIG_PM
-static int op_arm_suspend(struct platform_device *dev, pm_message_t state)
-{
-        mutex_lock(&op_arm_mutex);
-        if (op_arm_enabled)
-                op_perf_stop();
-        mutex_unlock(&op_arm_mutex);
-        return 0;
-}
-
-static int op_arm_resume(struct platform_device *dev)
-{
-        mutex_lock(&op_arm_mutex);
-        if (op_arm_enabled && op_perf_start())
-                op_arm_enabled = 0;
-        mutex_unlock(&op_arm_mutex);
-        return 0;
-}
-
-static struct platform_driver oprofile_driver = {
-        .driver         = {
-                .name           = "arm-oprofile",
-        },
-        .resume         = op_arm_resume,
-        .suspend        = op_arm_suspend,
-};
-
-static struct platform_device *oprofile_pdev;
-
-static int __init init_driverfs(void)
-{
-        int ret;
-
-        ret = platform_driver_register(&oprofile_driver);
-        if (ret)
-                goto out;
-
-        oprofile_pdev = platform_device_register_simple(
-                                oprofile_driver.driver.name, 0, NULL, 0);
-        if (IS_ERR(oprofile_pdev)) {
-                ret = PTR_ERR(oprofile_pdev);
-                platform_driver_unregister(&oprofile_driver);
-        }
-
-out:
-        return ret;
-}
-
-static void  exit_driverfs(void)
-{
-        platform_device_unregister(oprofile_pdev);
-        platform_driver_unregister(&oprofile_driver);
-}
-#else
-static int __init init_driverfs(void) { return 0; }
-#define exit_driverfs() do { } while (0)
-#endif /* CONFIG_PM */
-
 static int report_trace(struct stackframe *frame, void *d)
 {
         unsigned int *depth = d;
@@ -350,74 +111,14 @@ static void arm_backtrace(struct pt_regs * const regs, unsigned int depth)
 
 int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
-        int cpu, ret = 0;
-
-        perf_num_counters = armpmu_get_max_events();
-
-        counter_config = kcalloc(perf_num_counters,
-                        sizeof(struct op_counter_config), GFP_KERNEL);
-
-        if (!counter_config) {
-                pr_info("oprofile: failed to allocate %d "
-                                "counters\n", perf_num_counters);
-                return -ENOMEM;
-        }
-
-        ret = init_driverfs();
-        if (ret) {
-                kfree(counter_config);
-                counter_config = NULL;
-                return ret;
-        }
-
-        for_each_possible_cpu(cpu) {
-                perf_events[cpu] = kcalloc(perf_num_counters,
-                                sizeof(struct perf_event *), GFP_KERNEL);
-                if (!perf_events[cpu]) {
-                        pr_info("oprofile: failed to allocate %d perf events "
-                                        "for cpu %d\n", perf_num_counters, cpu);
-                        while (--cpu >= 0)
-                                kfree(perf_events[cpu]);
-                        return -ENOMEM;
-                }
-        }
-
         ops->backtrace          = arm_backtrace;
-        ops->create_files       = op_arm_create_files;
-        ops->setup              = op_arm_setup;
-        ops->start              = op_arm_start;
-        ops->stop               = op_arm_stop;
-        ops->shutdown           = op_arm_stop;
-        ops->cpu_type           = op_name_from_perf_id(armpmu_get_pmu_id());
-
-        if (!ops->cpu_type)
-                ret = -ENODEV;
-        else
-                pr_info("oprofile: using %s\n", ops->cpu_type);
 
-        return ret;
+        return oprofile_perf_init(ops);
 }
 
-void oprofile_arch_exit(void)
+void __exit oprofile_arch_exit(void)
 {
-        int cpu, id;
-        struct perf_event *event;
-
-        if (*perf_events) {
-                for_each_possible_cpu(cpu) {
-                        for (id = 0; id < perf_num_counters; ++id) {
-                                event = perf_events[cpu][id];
-                                if (event != NULL)
-                                        perf_event_release_kernel(event);
-                        }
-                        kfree(perf_events[cpu]);
-                }
-        }
-
-        if (counter_config) {
-                kfree(counter_config);
-                exit_driverfs();
-        }
+        oprofile_perf_exit();
 }
 #else
 int __init oprofile_arch_init(struct oprofile_operations *ops)
@@ -425,5 +126,5 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
         pr_info("oprofile: hardware counters not available\n");
         return -ENODEV;
 }
-void oprofile_arch_exit(void) {}
+void __exit oprofile_arch_exit(void) {}
 #endif /* CONFIG_HW_PERF_EVENTS */
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 33990fa95af0..35b6c3f85173 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -249,6 +249,11 @@ config ARCH_SHMOBILE
         select PM
         select PM_RUNTIME
 
+config CPU_HAS_PMU
+       depends on CPU_SH4 || CPU_SH4A
+       default y
+       bool
+
 if SUPERH32
 
 choice
@@ -738,6 +743,14 @@ config GUSA_RB
           LLSC, this should be more efficient than the other alternative of
           disabling interrupts around the atomic sequence.
 
+config HW_PERF_EVENTS
+        bool "Enable hardware performance counter support for perf events"
+        depends on PERF_EVENTS && CPU_HAS_PMU
+        default y
+        help
+          Enable hardware performance counter support for perf events. If
+          disabled, perf events will use software events only.
+
 source "drivers/sh/Kconfig"
 
 endmenu
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 036f7a9296fa..5a4b33435650 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -59,6 +59,24 @@ static inline int sh_pmu_initialized(void)
         return !!sh_pmu;
 }
 
+const char *perf_pmu_name(void)
+{
+        if (!sh_pmu)
+                return NULL;
+
+        return sh_pmu->name;
+}
+EXPORT_SYMBOL_GPL(perf_pmu_name);
+
+int perf_num_counters(void)
+{
+        if (!sh_pmu)
+                return 0;
+
+        return sh_pmu->num_events;
+}
+EXPORT_SYMBOL_GPL(perf_num_counters);
+
 /*
  * Release the PMU if this is the last perf_event.
  */
diff --git a/arch/sh/oprofile/Makefile b/arch/sh/oprofile/Makefile
index 4886c5c1786c..e85aae73e3dc 100644
--- a/arch/sh/oprofile/Makefile
+++ b/arch/sh/oprofile/Makefile
@@ -6,4 +6,8 @@ DRIVER_OBJS = $(addprefix ../../../drivers/oprofile/, \
                 oprofilefs.o oprofile_stats.o \
                 timer_int.o )
 
+ifeq ($(CONFIG_HW_PERF_EVENTS),y)
+DRIVER_OBJS += $(addprefix ../../../drivers/oprofile/, oprofile_perf.o)
+endif
+
 oprofile-y      := $(DRIVER_OBJS) common.o backtrace.o
diff --git a/arch/sh/oprofile/common.c b/arch/sh/oprofile/common.c
index ac604937f3ee..e10d89376f9b 100644
--- a/arch/sh/oprofile/common.c
+++ b/arch/sh/oprofile/common.c
@@ -17,114 +17,45 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
+#include <linux/perf_event.h>
 #include <asm/processor.h>
-#include "op_impl.h"
-
-static struct op_sh_model *model;
-
-static struct op_counter_config ctr[20];
 
+#ifdef CONFIG_HW_PERF_EVENTS
 extern void sh_backtrace(struct pt_regs * const regs, unsigned int depth);
 
-static int op_sh_setup(void)
-{
-        /* Pre-compute the values to stuff in the hardware registers.  */
-        model->reg_setup(ctr);
-
-        /* Configure the registers on all cpus.  */
-        on_each_cpu(model->cpu_setup, NULL, 1);
-
-        return 0;
-}
-
-static int op_sh_create_files(struct super_block *sb, struct dentry *root)
+char *op_name_from_perf_id(void)
 {
-        int i, ret = 0;
+        const char *pmu;
+        char buf[20];
+        int size;
 
-        for (i = 0; i < model->num_counters; i++) {
-                struct dentry *dir;
-                char buf[4];
+        pmu = perf_pmu_name();
+        if (!pmu)
+                return NULL;
 
-                snprintf(buf, sizeof(buf), "%d", i);
-                dir = oprofilefs_mkdir(sb, root, buf);
+        size = snprintf(buf, sizeof(buf), "sh/%s", pmu);
+        if (size > -1 && size < sizeof(buf))
+                return buf;
 
-                ret |= oprofilefs_create_ulong(sb, dir, "enabled", &ctr[i].enabled);
-                ret |= oprofilefs_create_ulong(sb, dir, "event", &ctr[i].event);
-                ret |= oprofilefs_create_ulong(sb, dir, "kernel", &ctr[i].kernel);
-                ret |= oprofilefs_create_ulong(sb, dir, "user", &ctr[i].user);
-
-                if (model->create_files)
-                        ret |= model->create_files(sb, dir);
-                else
-                        ret |= oprofilefs_create_ulong(sb, dir, "count", &ctr[i].count);
-
-                /* Dummy entries */
-                ret |= oprofilefs_create_ulong(sb, dir, "unit_mask", &ctr[i].unit_mask);
-        }
-
-        return ret;
+        return NULL;
 }
 
-static int op_sh_start(void)
+int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
-        /* Enable performance monitoring for all counters.  */
-        on_each_cpu(model->cpu_start, NULL, 1);
+        ops->backtrace = sh_backtrace;
 
-        return 0;
+        return oprofile_perf_init(ops);
 }
 
-static void op_sh_stop(void)
+void __exit oprofile_arch_exit(void)
 {
-        /* Disable performance monitoring for all counters.  */
-        on_each_cpu(model->cpu_stop, NULL, 1);
+        oprofile_perf_exit();
 }
-
+#else
 int __init oprofile_arch_init(struct oprofile_operations *ops)
 {
-        struct op_sh_model *lmodel = NULL;
-        int ret;
-
-        /*
-         * Always assign the backtrace op. If the counter initialization
-         * fails, we fall back to the timer which will still make use of
-         * this.
-         */
-        ops->backtrace = sh_backtrace;
-
-        /*
-         * XXX
-         *
-         * All of the SH7750/SH-4A counters have been converted to perf,
-         * this infrastructure hook is left for other users until they've
-         * had a chance to convert over, at which point all of this
-         * will be deleted.
-         */
-
-        if (!lmodel)
-                return -ENODEV;
-        if (!(current_cpu_data.flags & CPU_HAS_PERF_COUNTER))
-                return -ENODEV;
-
-        ret = lmodel->init();
-        if (unlikely(ret != 0))
-                return ret;
-
-        model = lmodel;
-
-        ops->setup              = op_sh_setup;
-        ops->create_files       = op_sh_create_files;
-        ops->start              = op_sh_start;
-        ops->stop               = op_sh_stop;
-        ops->cpu_type           = lmodel->cpu_type;
-
-        printk(KERN_INFO "oprofile: using %s performance monitoring.\n",
-               lmodel->cpu_type);
-
-        return 0;
-}
-
-void oprofile_arch_exit(void)
-{
-        if (model && model->exit)
-                model->exit();
+        pr_info("oprofile: hardware counters not available\n");
+        return -ENODEV;
 }
+void __exit oprofile_arch_exit(void) {}
+#endif /* CONFIG_HW_PERF_EVENTS */
diff --git a/arch/sh/oprofile/op_impl.h b/arch/sh/oprofile/op_impl.h
deleted file mode 100644
index 1244479ceb29..000000000000
--- a/arch/sh/oprofile/op_impl.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef __OP_IMPL_H
-#define __OP_IMPL_H
-
-/* Per-counter configuration as set via oprofilefs.  */
-struct op_counter_config {
-        unsigned long enabled;
-        unsigned long event;
-
-        unsigned long count;
-
-        /* Dummy values for userspace tool compliance */
-        unsigned long kernel;
-        unsigned long user;
-        unsigned long unit_mask;
-};
-
-/* Per-architecture configury and hooks.  */
-struct op_sh_model {
-        void (*reg_setup)(struct op_counter_config *);
-        int (*create_files)(struct super_block *sb, struct dentry *dir);
-        void (*cpu_setup)(void *dummy);
-        int (*init)(void);
-        void (*exit)(void);
-        void (*cpu_start)(void *args);
-        void (*cpu_stop)(void *args);
-        char *cpu_type;
-        unsigned char num_counters;
-};
-
-/* arch/sh/oprofile/common.c */
-extern void sh_backtrace(struct pt_regs * const regs, unsigned int depth);
-
-#endif /* __OP_IMPL_H */
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index 3855096c59b8..2d49d4e19a36 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -14,6 +14,7 @@
 #include <asm/ptrace.h>
 #include <asm/uaccess.h>
 #include <asm/stacktrace.h>
+#include <linux/compat.h>
 
 static void backtrace_warning_symbol(void *data, char *msg,
                                      unsigned long symbol)
@@ -48,14 +49,12 @@ static struct stacktrace_ops backtrace_ops = {
         .walk_stack     = print_context_stack,
 };
 
-struct frame_head {
-        struct frame_head *bp;
-        unsigned long ret;
-} __attribute__((packed));
-
-static struct frame_head *dump_user_backtrace(struct frame_head *head)
+#ifdef CONFIG_COMPAT
+static struct stack_frame_ia32 *
+dump_user_backtrace_32(struct stack_frame_ia32 *head)
 {
-        struct frame_head bufhead[2];
+        struct stack_frame_ia32 bufhead[2];
+        struct stack_frame_ia32 *fp;
 
         /* Also check accessibility of one struct frame_head beyond */
         if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
@@ -63,20 +62,66 @@ static struct frame_head *dump_user_backtrace(struct frame_head *head)
         if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
                 return NULL;
 
-        oprofile_add_trace(bufhead[0].ret);
+        fp = (struct stack_frame_ia32 *) compat_ptr(bufhead[0].next_frame);
+
+        oprofile_add_trace(bufhead[0].return_address);
+
+        /* frame pointers should strictly progress back up the stack
+        * (towards higher addresses) */
+        if (head >= fp)
+                return NULL;
+
+        return fp;
+}
+
+static inline int
+x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
+{
+        struct stack_frame_ia32 *head;
+
+        /* User process is 32-bit */
+        if (!current || !test_thread_flag(TIF_IA32))
+                return 0;
+
+        head = (struct stack_frame_ia32 *) regs->bp;
+        while (depth-- && head)
+                head = dump_user_backtrace_32(head);
+
+        return 1;
+}
+
+#else
+static inline int
+x86_backtrace_32(struct pt_regs * const regs, unsigned int depth)
+{
+        return 0;
+}
+#endif /* CONFIG_COMPAT */
+
+static struct stack_frame *dump_user_backtrace(struct stack_frame *head)
+{
+        struct stack_frame bufhead[2];
+
+        /* Also check accessibility of one struct stack_frame beyond */
+        if (!access_ok(VERIFY_READ, head, sizeof(bufhead)))
+                return NULL;
+        if (__copy_from_user_inatomic(bufhead, head, sizeof(bufhead)))
+                return NULL;
+
+        oprofile_add_trace(bufhead[0].return_address);
 
         /* frame pointers should strictly progress back up the stack
          * (towards higher addresses) */
-        if (head >= bufhead[0].bp)
+        if (head >= bufhead[0].next_frame)
                 return NULL;
 
-        return bufhead[0].bp;
+        return bufhead[0].next_frame;
 }
 
 void
 x86_backtrace(struct pt_regs * const regs, unsigned int depth)
 {
-        struct frame_head *head = (struct frame_head *)frame_pointer(regs);
+        struct stack_frame *head = (struct stack_frame *)frame_pointer(regs);
 
         if (!user_mode_vm(regs)) {
                 unsigned long stack = kernel_stack_pointer(regs);
@@ -86,6 +131,9 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
                 return;
         }
 
+        if (x86_backtrace_32(regs, depth))
+                return;
+
         while (depth-- && head)
                 head = dump_user_backtrace(head);
 }
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index f1575c9a2572..bd1489c3ce09 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -695,9 +695,6 @@ static int __init ppro_init(char **cpu_type)
         return 1;
 }
 
-/* in order to get sysfs right */
-static int using_nmi;
-
 int __init op_nmi_init(struct oprofile_operations *ops)
 {
         __u8 vendor = boot_cpu_data.x86_vendor;
@@ -705,8 +702,6 @@ int __init op_nmi_init(struct oprofile_operations *ops)
         char *cpu_type = NULL;
         int ret = 0;
 
-        using_nmi = 0;
-
         if (!cpu_has_apic)
                 return -ENODEV;
 
@@ -790,13 +785,11 @@ int __init op_nmi_init(struct oprofile_operations *ops)
         if (ret)
                 return ret;
 
-        using_nmi = 1;
         printk(KERN_INFO "oprofile: using NMI interrupt.\n");
         return 0;
 }
 
 void op_nmi_exit(void)
 {
-        if (using_nmi)
-                exit_sysfs();
+        exit_sysfs();
 }