*/
#include <linux/sched.h>
+#include <linux/oprofile.h>
#include <linux/vmalloc.h>
#include <linux/errno.h>
+#include "event_buffer.h"
#include "cpu_buffer.h"
#include "buffer_sync.h"
#include "oprof.h"
#define DEFAULT_TIMER_EXPIRE (HZ / 10)
int work_enabled;
-static void __free_cpu_buffers(int num)
+void free_cpu_buffers(void)
{
int i;
for_each_online_cpu(i) {
- if (cpu_buffer[i].buffer)
- vfree(cpu_buffer[i].buffer);
+ vfree(cpu_buffer[i].buffer);
}
}
b->last_task = NULL;
b->last_is_kernel = -1;
+ b->tracing = 0;
b->buffer_size = buffer_size;
b->tail_pos = 0;
b->head_pos = 0;
return 0;
fail:
- __free_cpu_buffers(i);
+ free_cpu_buffers();
return -ENOMEM;
}
-void free_cpu_buffers(void)
-{
- __free_cpu_buffers(NR_CPUS);
-}
-
-
void start_cpu_work(void)
{
int i;
}
+/* Resets the cpu buffer to a sane state. */
+void cpu_buffer_reset(struct oprofile_cpu_buffer * cpu_buf)
+{
+ /* reset these to invalid values; the next sample
+ * collected will populate the buffer with proper
+ * values to initialize the buffer
+ */
+ cpu_buf->last_is_kernel = -1;
+ cpu_buf->last_task = NULL;
+}
+
+
/* compute number of available slots in cpu_buffer queue */
static unsigned long nr_available_slots(struct oprofile_cpu_buffer const * b)
{
* increment is visible */
wmb();
- if (new_head < (b->buffer_size))
+ if (new_head < b->buffer_size)
b->head_pos = new_head;
else
b->head_pos = 0;
}
+
+
+inline static void
+add_sample(struct oprofile_cpu_buffer * cpu_buf,
+ unsigned long pc, unsigned long event)
+{
+ struct op_sample * entry = &cpu_buf->buffer[cpu_buf->head_pos];
+ entry->eip = pc;
+ entry->event = event;
+ increment_head(cpu_buf);
+}
+
+
+inline static void
+add_code(struct oprofile_cpu_buffer * buffer, unsigned long value)
+{
+ add_sample(buffer, ESCAPE_CODE, value);
+}
+
+
/* This must be safe from any context. It's safe writing here
* because of the head/tail separation of the writer and reader
* of the CPU buffer.
*
* is_kernel is needed because on some architectures you cannot
* tell if you are in kernel or user space simply by looking at
- * eip. We tag this in the buffer by generating kernel enter/exit
+ * pc. We tag this in the buffer by generating kernel enter/exit
* events whenever is_kernel changes
*/
-void oprofile_add_sample(unsigned long eip, unsigned int is_kernel,
- unsigned long event, int cpu)
+static int log_sample(struct oprofile_cpu_buffer * cpu_buf, unsigned long pc,
+ int is_kernel, unsigned long event)
{
- struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[cpu];
struct task_struct * task;
- is_kernel = !!is_kernel;
-
cpu_buf->sample_received++;
-
if (nr_available_slots(cpu_buf) < 3) {
cpu_buf->sample_lost_overflow++;
- return;
+ return 0;
}
+ is_kernel = !!is_kernel;
+
task = current;
/* notice a switch from user->kernel or vice versa */
if (cpu_buf->last_is_kernel != is_kernel) {
cpu_buf->last_is_kernel = is_kernel;
- cpu_buf->buffer[cpu_buf->head_pos].eip = ~0UL;
- cpu_buf->buffer[cpu_buf->head_pos].event = is_kernel;
- increment_head(cpu_buf);
+ add_code(cpu_buf, is_kernel);
}
/* notice a task switch */
if (cpu_buf->last_task != task) {
cpu_buf->last_task = task;
- cpu_buf->buffer[cpu_buf->head_pos].eip = ~0UL;
- cpu_buf->buffer[cpu_buf->head_pos].event = (unsigned long)task;
- increment_head(cpu_buf);
+ add_code(cpu_buf, (unsigned long)task);
}
- cpu_buf->buffer[cpu_buf->head_pos].eip = eip;
- cpu_buf->buffer[cpu_buf->head_pos].event = event;
- increment_head(cpu_buf);
+ add_sample(cpu_buf, pc, event);
+ return 1;
}
+static int oprofile_begin_trace(struct oprofile_cpu_buffer * cpu_buf)
+{
+ if (nr_available_slots(cpu_buf) < 4) {
+ cpu_buf->sample_lost_overflow++;
+ return 0;
+ }
-/* Resets the cpu buffer to a sane state. */
-void cpu_buffer_reset(struct oprofile_cpu_buffer * cpu_buf)
+ add_code(cpu_buf, CPU_TRACE_BEGIN);
+ cpu_buf->tracing = 1;
+ return 1;
+}
+
+
+static void oprofile_end_trace(struct oprofile_cpu_buffer * cpu_buf)
{
- /* reset these to invalid values; the next sample
- * collected will populate the buffer with proper
- * values to initialize the buffer
- */
- cpu_buf->last_is_kernel = -1;
- cpu_buf->last_task = NULL;
+ cpu_buf->tracing = 0;
+}
+
+
+void oprofile_add_sample(struct pt_regs * const regs, unsigned long event)
+{
+ struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()];
+ unsigned long pc = profile_pc(regs);
+ int is_kernel = !user_mode(regs);
+
+ if (!backtrace_depth) {
+ log_sample(cpu_buf, pc, is_kernel, event);
+ return;
+ }
+
+ if (!oprofile_begin_trace(cpu_buf))
+ return;
+
+ /* if log_sample() fail we can't backtrace since we lost the source
+ * of this event */
+ if (log_sample(cpu_buf, pc, is_kernel, event))
+ oprofile_ops.backtrace(regs, backtrace_depth);
+ oprofile_end_trace(cpu_buf);
}
+void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event)
+{
+ struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()];
+ log_sample(cpu_buf, pc, is_kernel, event);
+}
+
+
+void oprofile_add_trace(unsigned long pc)
+{
+ struct oprofile_cpu_buffer * cpu_buf = &cpu_buffer[smp_processor_id()];
+
+ if (!cpu_buf->tracing)
+ return;
+
+ if (nr_available_slots(cpu_buf) < 1) {
+ cpu_buf->tracing = 0;
+ cpu_buf->sample_lost_overflow++;
+ return;
+ }
+
+ /* broken frame can give an eip with the same value as an escape code,
+ * abort the trace if we get it */
+ if (pc == ESCAPE_CODE) {
+ cpu_buf->tracing = 0;
+ cpu_buf->backtrace_aborted++;
+ return;
+ }
+
+ add_sample(cpu_buf, pc, 0);
+}
+
+
+
/*
* This serves to avoid cpu buffer overflow, and makes sure
* the task mortuary progresses
*/
static void wq_sync_buffer(void * data)
{
- struct oprofile_cpu_buffer * b = (struct oprofile_cpu_buffer *)data;
+ struct oprofile_cpu_buffer * b = data;
if (b->cpu != smp_processor_id()) {
printk("WQ on CPU%d, prefer CPU%d\n",
smp_processor_id(), b->cpu);
git://git.onelab.eu / linux-2.6.git / blobdiff