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path: root/drivers/oprofile/buffer_sync.c
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Diffstat (limited to 'drivers/oprofile/buffer_sync.c')
-rw-r--r--drivers/oprofile/buffer_sync.c117
1 files changed, 40 insertions, 77 deletions
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index b55cd23ffdef..737bd9484822 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -268,18 +268,6 @@ lookup_dcookie(struct mm_struct *mm, unsigned long addr, off_t *offset)
return cookie;
}
-static void increment_tail(struct oprofile_cpu_buffer *b)
-{
- unsigned long new_tail = b->tail_pos + 1;
-
- rmb(); /* be sure fifo pointers are synchromized */
-
- if (new_tail < b->buffer_size)
- b->tail_pos = new_tail;
- else
- b->tail_pos = 0;
-}
-
static unsigned long last_cookie = INVALID_COOKIE;
static void add_cpu_switch(int i)
@@ -331,28 +319,25 @@ static void add_trace_begin(void)
#define IBS_FETCH_CODE_SIZE 2
#define IBS_OP_CODE_SIZE 5
-#define IBS_EIP(offset) \
- (((struct op_sample *)&cpu_buf->buffer[(offset)])->eip)
-#define IBS_EVENT(offset) \
- (((struct op_sample *)&cpu_buf->buffer[(offset)])->event)
/*
* Add IBS fetch and op entries to event buffer
*/
-static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
- struct mm_struct *mm)
+static void add_ibs_begin(int cpu, int code, struct mm_struct *mm)
{
unsigned long rip;
int i, count;
unsigned long ibs_cookie = 0;
off_t offset;
+ struct op_sample *sample;
- increment_tail(cpu_buf); /* move to RIP entry */
-
- rip = IBS_EIP(cpu_buf->tail_pos);
+ sample = cpu_buffer_read_entry(cpu);
+ if (!sample)
+ goto Error;
+ rip = sample->eip;
#ifdef __LP64__
- rip += IBS_EVENT(cpu_buf->tail_pos) << 32;
+ rip += sample->event << 32;
#endif
if (mm) {
@@ -376,8 +361,8 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
add_event_entry(offset); /* Offset from Dcookie */
/* we send the Dcookie offset, but send the raw Linear Add also*/
- add_event_entry(IBS_EIP(cpu_buf->tail_pos));
- add_event_entry(IBS_EVENT(cpu_buf->tail_pos));
+ add_event_entry(sample->eip);
+ add_event_entry(sample->event);
if (code == IBS_FETCH_CODE)
count = IBS_FETCH_CODE_SIZE; /*IBS FETCH is 2 int64s*/
@@ -385,10 +370,17 @@ static void add_ibs_begin(struct oprofile_cpu_buffer *cpu_buf, int code,
count = IBS_OP_CODE_SIZE; /*IBS OP is 5 int64s*/
for (i = 0; i < count; i++) {
- increment_tail(cpu_buf);
- add_event_entry(IBS_EIP(cpu_buf->tail_pos));
- add_event_entry(IBS_EVENT(cpu_buf->tail_pos));
+ sample = cpu_buffer_read_entry(cpu);
+ if (!sample)
+ goto Error;
+ add_event_entry(sample->eip);
+ add_event_entry(sample->event);
}
+
+ return;
+
+Error:
+ return;
}
#endif
@@ -466,33 +458,6 @@ static inline int is_code(unsigned long val)
}
-/* "acquire" as many cpu buffer slots as we can */
-static unsigned long get_slots(struct oprofile_cpu_buffer *b)
-{
- unsigned long head = b->head_pos;
- unsigned long tail = b->tail_pos;
-
- /*
- * Subtle. This resets the persistent last_task
- * and in_kernel values used for switching notes.
- * BUT, there is a small window between reading
- * head_pos, and this call, that means samples
- * can appear at the new head position, but not
- * be prefixed with the notes for switching
- * kernel mode or a task switch. This small hole
- * can lead to mis-attribution or samples where
- * we don't know if it's in the kernel or not,
- * at the start of an event buffer.
- */
- cpu_buffer_reset(b);
-
- if (head >= tail)
- return head - tail;
-
- return head + (b->buffer_size - tail);
-}
-
-
/* Move tasks along towards death. Any tasks on dead_tasks
* will definitely have no remaining references in any
* CPU buffers at this point, because we use two lists,
@@ -559,61 +524,61 @@ typedef enum {
*/
void sync_buffer(int cpu)
{
- struct oprofile_cpu_buffer *cpu_buf = &per_cpu(cpu_buffer, cpu);
struct mm_struct *mm = NULL;
+ struct mm_struct *oldmm;
struct task_struct *new;
unsigned long cookie = 0;
int in_kernel = 1;
sync_buffer_state state = sb_buffer_start;
-#ifndef CONFIG_OPROFILE_IBS
unsigned int i;
unsigned long available;
-#endif
mutex_lock(&buffer_mutex);
add_cpu_switch(cpu);
- /* Remember, only we can modify tail_pos */
-
-#ifndef CONFIG_OPROFILE_IBS
- available = get_slots(cpu_buf);
+ cpu_buffer_reset(cpu);
+ available = cpu_buffer_entries(cpu);
for (i = 0; i < available; ++i) {
-#else
- while (get_slots(cpu_buf)) {
-#endif
- struct op_sample *s = &cpu_buf->buffer[cpu_buf->tail_pos];
+ struct op_sample *s = cpu_buffer_read_entry(cpu);
+ if (!s)
+ break;
if (is_code(s->eip)) {
- if (s->event <= CPU_IS_KERNEL) {
+ switch (s->event) {
+ case 0:
+ case 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) {
+ break;
+ case CPU_TRACE_BEGIN:
state = sb_bt_start;
add_trace_begin();
+ break;
#ifdef CONFIG_OPROFILE_IBS
- } else if (s->event == IBS_FETCH_BEGIN) {
+ case IBS_FETCH_BEGIN:
state = sb_bt_start;
- add_ibs_begin(cpu_buf, IBS_FETCH_CODE, mm);
- } else if (s->event == IBS_OP_BEGIN) {
+ add_ibs_begin(cpu, IBS_FETCH_CODE, mm);
+ break;
+ case IBS_OP_BEGIN:
state = sb_bt_start;
- add_ibs_begin(cpu_buf, IBS_OP_CODE, mm);
+ add_ibs_begin(cpu, IBS_OP_CODE, mm);
+ break;
#endif
- } else {
- struct mm_struct *oldmm = mm;
-
+ default:
/* userspace context switch */
+ oldmm = mm;
new = (struct task_struct *)s->event;
-
release_mm(oldmm);
mm = take_tasks_mm(new);
if (mm != oldmm)
cookie = get_exec_dcookie(mm);
add_user_ctx_switch(new, cookie);
+ break;
}
} else if (state >= sb_bt_start &&
!add_sample(mm, s, in_kernel)) {
@@ -622,8 +587,6 @@ void sync_buffer(int cpu)
atomic_inc(&oprofile_stats.bt_lost_no_mapping);
}
}
-
- increment_tail(cpu_buf);
}
release_mm(mm);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-18 11:42:36 +0300