2009-03-05 15:32:12

by Metzger, Markus T

[permalink] [raw]
Subject: [patch 4/4] x86, hw-branch-tracer: add selftest

Add a selftest to the hw-branch-tracer.

Signed-off-by: Markus Metzger <[email protected]>
---

Index: gits/kernel/trace/trace_hw_branches.c
===================================================================
--- gits.orig/kernel/trace/trace_hw_branches.c 2009-03-03 10:45:35.000000000 +0100
+++ gits/kernel/trace/trace_hw_branches.c 2009-03-03 10:50:04.000000000 +0100
@@ -344,7 +344,10 @@ struct tracer bts_tracer __read_mostly =
.start = bts_trace_start,
.stop = bts_trace_stop,
.open = trace_bts_prepare,
- .close = trace_bts_close
+ .close = trace_bts_close,
+#ifdef CONFIG_FTRACE_SELFTEST
+ .selftest = trace_selftest_startup_hw_branches,
+#endif /* CONFIG_FTRACE_SELFTEST */
};

__init static int init_bts_trace(void)
Index: gits/kernel/trace/trace_selftest.c
===================================================================
--- gits.orig/kernel/trace/trace_selftest.c 2009-03-03 09:32:43.000000000 +0100
+++ gits/kernel/trace/trace_selftest.c 2009-03-03 10:51:27.000000000 +0100
@@ -15,6 +15,7 @@ static inline int trace_valid_entry(stru
case TRACE_BRANCH:
case TRACE_GRAPH_ENT:
case TRACE_GRAPH_RET:
+ case TRACE_HW_BRANCHES:
return 1;
}
return 0;
@@ -693,3 +694,56 @@ trace_selftest_startup_branch(struct tra
return ret;
}
#endif /* CONFIG_BRANCH_TRACER */
+
+#ifdef CONFIG_HW_BRANCH_TRACER
+int
+trace_selftest_startup_hw_branches(struct tracer *trace,
+ struct trace_array *tr)
+{
+ unsigned long count;
+ int ret;
+ struct trace_iterator iter;
+ struct tracer tracer;
+
+ if (!trace->open) {
+ printk(KERN_CONT "missing open function...");
+ return -1;
+ }
+
+ /* start the tracing */
+ ret = tracer_init(trace, tr);
+ if (ret) {
+ warn_failed_init_tracer(trace, ret);
+ return ret;
+ }
+
+ /* the hw-branch tracer needs to collect the trace from the various
+ * cpu trace buffers - before tracing is stopped. */
+ memset(&iter, 0, sizeof(iter));
+ memcpy(&tracer, trace, sizeof(tracer));
+
+ iter.trace = &tracer;
+ iter.tr = tr;
+ iter.pos = -1;
+ mutex_init(&iter.mutex);
+
+ trace->open(&iter);
+
+ mutex_destroy(&iter.mutex);
+
+ /* stop the tracing. */
+ tracing_stop();
+
+ /* check the trace buffer */
+ ret = trace_test_buffer(tr, &count);
+ trace->reset(tr);
+ tracing_start();
+
+ if (!ret && !count) {
+ printk(KERN_CONT "no entries found..");
+ ret = -1;
+ }
+
+ return ret;
+}
+#endif /* CONFIG_HW_BRANCH_TRACER */
Index: gits/kernel/trace/trace.h
===================================================================
--- gits.orig/kernel/trace/trace.h 2009-03-03 09:32:43.000000000 +0100
+++ gits/kernel/trace/trace.h 2009-03-03 10:50:04.000000000 +0100
@@ -555,6 +555,8 @@ extern int trace_selftest_startup_syspro
struct trace_array *tr);
extern int trace_selftest_startup_branch(struct tracer *trace,
struct trace_array *tr);
+extern int trace_selftest_startup_hw_branches(struct tracer *trace,
+ struct trace_array *tr);
#endif /* CONFIG_FTRACE_STARTUP_TEST */

extern void *head_page(struct trace_array_cpu *data);
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2009-03-06 14:41:45

by Ingo Molnar

[permalink] [raw]
Subject: Re: [patch 4/4] x86, hw-branch-tracer: add selftest


* Markus Metzger <[email protected]> wrote:

> + /* the hw-branch tracer needs to collect the trace from the various
> + * cpu trace buffers - before tracing is stopped. */

The comment style is wrong here too.

Ingo