x86/oprofile: add IBS support for AMD CPUs, IBS buffer handling routines
This patchset supports the new profiling hardware available in the
latest AMD CPUs in the oProfile driver.
Signed-off-by: Barry Kasindorf <barry.kasindorf@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 2450b3a3..c9ac4e1 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -5,6 +5,7 @@
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
+ * @author Barry Kasindorf <barry.kasindorf@amd.com>
*
* Each CPU has a local buffer that stores PC value/event
* pairs. We also log context switches when we notice them.
@@ -207,7 +208,7 @@
return 1;
}
-static int oprofile_begin_trace(struct oprofile_cpu_buffer * cpu_buf)
+static int oprofile_begin_trace(struct oprofile_cpu_buffer *cpu_buf)
{
if (nr_available_slots(cpu_buf) < 4) {
cpu_buf->sample_lost_overflow++;
@@ -252,6 +253,71 @@
oprofile_add_ext_sample(pc, regs, event, is_kernel);
}
+#define MAX_IBS_SAMPLE_SIZE 14
+static int log_ibs_sample(struct oprofile_cpu_buffer *cpu_buf,
+ unsigned long pc, int is_kernel, unsigned int *ibs, int ibs_code)
+{
+ struct task_struct *task;
+
+ cpu_buf->sample_received++;
+
+ if (nr_available_slots(cpu_buf) < MAX_IBS_SAMPLE_SIZE) {
+ cpu_buf->sample_lost_overflow++;
+ return 0;
+ }
+
+ is_kernel = !!is_kernel;
+
+ /* notice a switch from user->kernel or vice versa */
+ if (cpu_buf->last_is_kernel != is_kernel) {
+ cpu_buf->last_is_kernel = is_kernel;
+ add_code(cpu_buf, is_kernel);
+ }
+
+ /* notice a task switch */
+ if (!is_kernel) {
+ task = current;
+
+ if (cpu_buf->last_task != task) {
+ cpu_buf->last_task = task;
+ add_code(cpu_buf, (unsigned long)task);
+ }
+ }
+
+ add_code(cpu_buf, ibs_code);
+ add_sample(cpu_buf, ibs[0], ibs[1]);
+ add_sample(cpu_buf, ibs[2], ibs[3]);
+ add_sample(cpu_buf, ibs[4], ibs[5]);
+
+ if (ibs_code == IBS_OP_BEGIN) {
+ add_sample(cpu_buf, ibs[6], ibs[7]);
+ add_sample(cpu_buf, ibs[8], ibs[9]);
+ add_sample(cpu_buf, ibs[10], ibs[11]);
+ }
+
+ return 1;
+}
+
+void oprofile_add_ibs_sample(struct pt_regs *const regs,
+ unsigned int * const ibs_sample, u8 code)
+{
+ int is_kernel = !user_mode(regs);
+ unsigned long pc = profile_pc(regs);
+
+ struct oprofile_cpu_buffer *cpu_buf =
+ &per_cpu(cpu_buffer, smp_processor_id());
+
+ if (!backtrace_depth) {
+ log_ibs_sample(cpu_buf, pc, is_kernel, ibs_sample, code);
+ return;
+ }
+
+ /* if log_sample() fails we can't backtrace since we lost the source
+ * of this event */
+ if (log_ibs_sample(cpu_buf, pc, is_kernel, ibs_sample, code))
+ oprofile_ops.backtrace(regs, backtrace_depth);
+}
+
void oprofile_add_pc(unsigned long pc, int is_kernel, unsigned long event)
{
struct oprofile_cpu_buffer *cpu_buf = &__get_cpu_var(cpu_buffer);