vserver 1.9.5.x5

[linux-2.6.git] / drivers / oprofile / buffer_sync.c

diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index 884a532..9ac2dab 100644 (file)
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -35,7 +35,7 @@
 static LIST_HEAD(dying_tasks);
 static LIST_HEAD(dead_tasks);
 cpumask_t marked_cpus = CPU_MASK_NONE;
-static spinlock_t task_mortuary = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(task_mortuary);
 void process_task_mortuary(void);
 
 
@@ -46,7 +46,7 @@ void process_task_mortuary(void);
  */
 static int task_free_notify(struct notifier_block * self, unsigned long val, void * data)
 {
-       struct task_struct * task = (struct task_struct *)data;
+       struct task_struct * task = data;
        spin_lock(&task_mortuary);
        list_add(&task->tasks, &dying_tasks);
        spin_unlock(&task_mortuary);
@@ -62,7 +62,7 @@ static int task_exit_notify(struct notifier_block * self, unsigned long val, voi
        /* To avoid latency problems, we only process the current CPU,
         * hoping that most samples for the task are on this CPU
         */
-       sync_buffer(smp_processor_id());
+       sync_buffer(_smp_processor_id());
        return 0;
 }
 
@@ -86,7 +86,7 @@ static int munmap_notify(struct notifier_block * self, unsigned long val, void *
                /* To avoid latency problems, we only process the current CPU,
                 * hoping that most samples for the task are on this CPU
                 */
-               sync_buffer(smp_processor_id());
+               sync_buffer(_smp_processor_id());
                return 0;
        }
 
@@ -296,6 +296,13 @@ static void add_cookie_switch(unsigned long cookie)
 }
 
  
+static void add_trace_begin(void)
+{
+       add_event_entry(ESCAPE_CODE);
+       add_event_entry(TRACE_BEGIN_CODE);
+}
+
+
 static void add_sample_entry(unsigned long offset, unsigned long event)
 {
        add_event_entry(offset);
@@ -303,7 +310,7 @@ static void add_sample_entry(unsigned long offset, unsigned long event)
 }
 
 
-static void add_us_sample(struct mm_struct * mm, struct op_sample * s)
+static int add_us_sample(struct mm_struct * mm, struct op_sample * s)
 {
        unsigned long cookie;
        off_t offset;
@@ -312,7 +319,7 @@ static void add_us_sample(struct mm_struct * mm, struct op_sample * s)
  
        if (!cookie) {
                atomic_inc(&oprofile_stats.sample_lost_no_mapping);
-               return;
+               return 0;
        }
 
        if (cookie != last_cookie) {
@@ -321,6 +328,8 @@ static void add_us_sample(struct mm_struct * mm, struct op_sample * s)
        }
 
        add_sample_entry(offset, s->event);
+
+       return 1;
 }
 
  
@@ -328,15 +337,18 @@ static void add_us_sample(struct mm_struct * mm, struct op_sample * s)
  * sample is converted into a persistent dentry/offset pair
  * for later lookup from userspace.
  */
-static void add_sample(struct mm_struct * mm, struct op_sample * s, int in_kernel)
+static int
+add_sample(struct mm_struct * mm, struct op_sample * s, int in_kernel)
 {
        if (in_kernel) {
                add_sample_entry(s->eip, s->event);
+               return 1;
        } else if (mm) {
-               add_us_sample(mm, s);
+               return add_us_sample(mm, s);
        } else {
                atomic_inc(&oprofile_stats.sample_lost_no_mm);
        }
+       return 0;
 }
  
 
@@ -358,9 +370,9 @@ static struct mm_struct * take_tasks_mm(struct task_struct * task)
 }
 
 
-static inline int is_ctx_switch(unsigned long val)
+static inline int is_code(unsigned long val)
 {
-       return val == ~0UL;
+       return val == ESCAPE_CODE;
 }
  
 
@@ -397,7 +409,7 @@ static void increment_tail(struct oprofile_cpu_buffer * b)
 
        rmb();
 
-       if (new_tail < (b->buffer_size))
+       if (new_tail < b->buffer_size)
                b->tail_pos = new_tail;
        else
                b->tail_pos = 0;
@@ -454,6 +466,17 @@ static void mark_done(int cpu)
 }
 
 
+/* FIXME: this is not sufficient if we implement syscall barrier backtrace
+ * traversal, the code switch to sb_sample_start at first kernel enter/exit
+ * switch so we need a fifth state and some special handling in sync_buffer()
+ */
+typedef enum {
+       sb_bt_ignore = -2,
+       sb_buffer_start,
+       sb_bt_start,
+       sb_sample_start,
+} sync_buffer_state;
+
 /* Sync one of the CPU's buffers into the global event buffer.
  * Here we need to go through each batch of samples punctuated
  * by context switch notes, taking the task's mmap_sem and doing
@@ -468,6 +491,7 @@ void sync_buffer(int cpu)
        unsigned long cookie = 0;
        int in_kernel = 1;
        unsigned int i;
+       sync_buffer_state state = sb_buffer_start;
        unsigned long available;
 
        down(&buffer_sem);
@@ -478,14 +502,19 @@ void sync_buffer(int cpu)
 
        available = get_slots(cpu_buf);
 
-       for (i=0; i < available; ++i) {
+       for (i = 0; i < available; ++i) {
                struct op_sample * s = &cpu_buf->buffer[cpu_buf->tail_pos];
  
-               if (is_ctx_switch(s->eip)) {
-                       if (s->event <= 1) {
+               if (is_code(s->eip)) {
+                       if (s->event <= CPU_IS_KERNEL) {
                                /* kernel/userspace switch */
                                in_kernel = s->event;
+                               if (state == sb_buffer_start)
+                                       state = sb_sample_start;
                                add_kernel_ctx_switch(s->event);
+                       } else if (s->event == CPU_TRACE_BEGIN) {
+                               state = sb_bt_start;
+                               add_trace_begin();
                        } else {
                                struct mm_struct * oldmm = mm;
 
@@ -499,7 +528,13 @@ void sync_buffer(int cpu)
                                add_user_ctx_switch(new, cookie);
                        }
                } else {
-                       add_sample(mm, s, in_kernel);
+                       if (state >= sb_bt_start &&
+                           !add_sample(mm, s, in_kernel)) {
+                               if (state == sb_bt_start) {
+                                       state = sb_bt_ignore;
+                                       atomic_inc(&oprofile_stats.bt_lost_no_mapping);
+                               }
+                       }
                }
 
                increment_tail(cpu_buf);