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path: root/drivers/oprofile
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-rw-r--r--drivers/oprofile/cpu_buffer.c63
-rw-r--r--drivers/oprofile/oprof.c12
-rw-r--r--drivers/oprofile/oprof.h3
-rw-r--r--drivers/oprofile/timer_int.c78
4 files changed, 92 insertions, 64 deletions
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 7581dbe..0ac8b06 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -30,23 +30,7 @@
#define OP_BUFFER_FLAGS 0
-/*
- * Read and write access is using spin locking. Thus, writing to the
- * buffer by NMI handler (x86) could occur also during critical
- * sections when reading the buffer. To avoid this, there are 2
- * buffers for independent read and write access. Read access is in
- * process context only, write access only in the NMI handler. If the
- * read buffer runs empty, both buffers are swapped atomically. There
- * is potentially a small window during swapping where the buffers are
- * disabled and samples could be lost.
- *
- * Using 2 buffers is a little bit overhead, but the solution is clear
- * and does not require changes in the ring buffer implementation. It
- * can be changed to a single buffer solution when the ring buffer
- * access is implemented as non-locking atomic code.
- */
-static struct ring_buffer *op_ring_buffer_read;
-static struct ring_buffer *op_ring_buffer_write;
+static struct ring_buffer *op_ring_buffer;
DEFINE_PER_CPU(struct oprofile_cpu_buffer, op_cpu_buffer);
static void wq_sync_buffer(struct work_struct *work);
@@ -68,12 +52,9 @@ void oprofile_cpu_buffer_inc_smpl_lost(void)
void free_cpu_buffers(void)
{
- if (op_ring_buffer_read)
- ring_buffer_free(op_ring_buffer_read);
- op_ring_buffer_read = NULL;
- if (op_ring_buffer_write)
- ring_buffer_free(op_ring_buffer_write);
- op_ring_buffer_write = NULL;
+ if (op_ring_buffer)
+ ring_buffer_free(op_ring_buffer);
+ op_ring_buffer = NULL;
}
#define RB_EVENT_HDR_SIZE 4
@@ -86,11 +67,8 @@ int alloc_cpu_buffers(void)
unsigned long byte_size = buffer_size * (sizeof(struct op_sample) +
RB_EVENT_HDR_SIZE);
- op_ring_buffer_read = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
- if (!op_ring_buffer_read)
- goto fail;
- op_ring_buffer_write = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
- if (!op_ring_buffer_write)
+ op_ring_buffer = ring_buffer_alloc(byte_size, OP_BUFFER_FLAGS);
+ if (!op_ring_buffer)
goto fail;
for_each_possible_cpu(i) {
@@ -162,16 +140,11 @@ struct op_sample
*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size)
{
entry->event = ring_buffer_lock_reserve
- (op_ring_buffer_write, sizeof(struct op_sample) +
+ (op_ring_buffer, sizeof(struct op_sample) +
size * sizeof(entry->sample->data[0]));
- if (entry->event)
- entry->sample = ring_buffer_event_data(entry->event);
- else
- entry->sample = NULL;
-
- if (!entry->sample)
+ if (!entry->event)
return NULL;
-
+ entry->sample = ring_buffer_event_data(entry->event);
entry->size = size;
entry->data = entry->sample->data;
@@ -180,25 +153,16 @@ struct op_sample
int op_cpu_buffer_write_commit(struct op_entry *entry)
{
- return ring_buffer_unlock_commit(op_ring_buffer_write, entry->event);
+ return ring_buffer_unlock_commit(op_ring_buffer, entry->event);
}
struct op_sample *op_cpu_buffer_read_entry(struct op_entry *entry, int cpu)
{
struct ring_buffer_event *e;
- e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL, NULL);
- if (e)
- goto event;
- if (ring_buffer_swap_cpu(op_ring_buffer_read,
- op_ring_buffer_write,
- cpu))
+ e = ring_buffer_consume(op_ring_buffer, cpu, NULL, NULL);
+ if (!e)
return NULL;
- e = ring_buffer_consume(op_ring_buffer_read, cpu, NULL, NULL);
- if (e)
- goto event;
- return NULL;
-event:
entry->event = e;
entry->sample = ring_buffer_event_data(e);
entry->size = (ring_buffer_event_length(e) - sizeof(struct op_sample))
@@ -209,8 +173,7 @@ event:
unsigned long op_cpu_buffer_entries(int cpu)
{
- return ring_buffer_entries_cpu(op_ring_buffer_read, cpu)
- + ring_buffer_entries_cpu(op_ring_buffer_write, cpu);
+ return ring_buffer_entries_cpu(op_ring_buffer, cpu);
}
static int
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c
index dc8a042..b336cd9 100644
--- a/drivers/oprofile/oprof.c
+++ b/drivers/oprofile/oprof.c
@@ -253,22 +253,26 @@ static int __init oprofile_init(void)
int err;
err = oprofile_arch_init(&oprofile_ops);
-
if (err < 0 || timer) {
printk(KERN_INFO "oprofile: using timer interrupt.\n");
- oprofile_timer_init(&oprofile_ops);
+ err = oprofile_timer_init(&oprofile_ops);
+ if (err)
+ goto out_arch;
}
-
err = oprofilefs_register();
if (err)
- oprofile_arch_exit();
+ goto out_arch;
+ return 0;
+out_arch:
+ oprofile_arch_exit();
return err;
}
static void __exit oprofile_exit(void)
{
+ oprofile_timer_exit();
oprofilefs_unregister();
oprofile_arch_exit();
}
diff --git a/drivers/oprofile/oprof.h b/drivers/oprofile/oprof.h
index cb92f5c..47e12cb 100644
--- a/drivers/oprofile/oprof.h
+++ b/drivers/oprofile/oprof.h
@@ -34,7 +34,8 @@ struct super_block;
struct dentry;
void oprofile_create_files(struct super_block *sb, struct dentry *root);
-void oprofile_timer_init(struct oprofile_operations *ops);
+int oprofile_timer_init(struct oprofile_operations *ops);
+void oprofile_timer_exit(void);
int oprofile_set_backtrace(unsigned long depth);
int oprofile_set_timeout(unsigned long time);
diff --git a/drivers/oprofile/timer_int.c b/drivers/oprofile/timer_int.c
index 333f915..dc0ae4d 100644
--- a/drivers/oprofile/timer_int.c
+++ b/drivers/oprofile/timer_int.c
@@ -13,34 +13,94 @@
#include <linux/oprofile.h>
#include <linux/profile.h>
#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/hrtimer.h>
+#include <asm/irq_regs.h>
#include <asm/ptrace.h>
#include "oprof.h"
-static int timer_notify(struct pt_regs *regs)
+static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
+
+static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
+{
+ oprofile_add_sample(get_irq_regs(), 0);
+ hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
+ return HRTIMER_RESTART;
+}
+
+static void __oprofile_hrtimer_start(void *unused)
+{
+ struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
+
+ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ hrtimer->function = oprofile_hrtimer_notify;
+
+ hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
+ HRTIMER_MODE_REL_PINNED);
+}
+
+static int oprofile_hrtimer_start(void)
{
- oprofile_add_sample(regs, 0);
+ on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
return 0;
}
-static int timer_start(void)
+static void __oprofile_hrtimer_stop(int cpu)
{
- return register_timer_hook(timer_notify);
+ struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
+
+ hrtimer_cancel(hrtimer);
}
+static void oprofile_hrtimer_stop(void)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu)
+ __oprofile_hrtimer_stop(cpu);
+}
-static void timer_stop(void)
+static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
+ unsigned long action, void *hcpu)
{
- unregister_timer_hook(timer_notify);
+ long cpu = (long) hcpu;
+
+ switch (action) {
+ case CPU_ONLINE:
+ case CPU_ONLINE_FROZEN:
+ smp_call_function_single(cpu, __oprofile_hrtimer_start,
+ NULL, 1);
+ break;
+ case CPU_DEAD:
+ case CPU_DEAD_FROZEN:
+ __oprofile_hrtimer_stop(cpu);
+ break;
+ }
+ return NOTIFY_OK;
}
+static struct notifier_block __refdata oprofile_cpu_notifier = {
+ .notifier_call = oprofile_cpu_notify,
+};
-void __init oprofile_timer_init(struct oprofile_operations *ops)
+int __init oprofile_timer_init(struct oprofile_operations *ops)
{
+ int rc;
+
+ rc = register_hotcpu_notifier(&oprofile_cpu_notifier);
+ if (rc)
+ return rc;
ops->create_files = NULL;
ops->setup = NULL;
ops->shutdown = NULL;
- ops->start = timer_start;
- ops->stop = timer_stop;
+ ops->start = oprofile_hrtimer_start;
+ ops->stop = oprofile_hrtimer_stop;
ops->cpu_type = "timer";
+ return 0;
+}
+
+void __exit oprofile_timer_exit(void)
+{
+ unregister_hotcpu_notifier(&oprofile_cpu_notifier);
}