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Subject[tip:tracing/core] x86, ds: selftest each cpu
Commit-ID:  01f6569ece6915616f6cae1d7d8b46ab8da9c1bd
Gitweb: http://git.kernel.org/tip/01f6569ece6915616f6cae1d7d8b46ab8da9c1bd
Author: Markus Metzger <markus.t.metzger@intel.com>
AuthorDate: Fri, 3 Apr 2009 16:43:44 +0200
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 7 Apr 2009 13:36:25 +0200

x86, ds: selftest each cpu

Perform debug store selftests on each cpu.

Cover both the normal and the _noirq variant of the debug store interface.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Cc: roland@redhat.com
Cc: eranian@googlemail.com
Cc: oleg@redhat.com
Cc: juan.villacis@intel.com
Cc: ak@linux.jf.intel.com
LKML-Reference: <20090403144559.394583000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
arch/x86/kernel/ds_selftest.c | 182 ++++++++++++++++++++++++++++++-----------
1 files changed, 135 insertions(+), 47 deletions(-)
diff --git a/arch/x86/kernel/ds_selftest.c b/arch/x86/kernel/ds_selftest.c
index cccc19a..599a963 100644
--- a/arch/x86/kernel/ds_selftest.c
+++ b/arch/x86/kernel/ds_selftest.c
@@ -11,13 +11,21 @@
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/smp.h>
+#include <linux/cpu.h>

#include <asm/ds.h>


-#define BUFFER_SIZE 1021 /* Intentionally chose an odd size. */
+#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */


+struct ds_selftest_bts_conf {
+ struct bts_tracer *tracer;
+ int error;
+ int (*suspend)(struct bts_tracer *);
+ int (*resume)(struct bts_tracer *);
+};
+
static int ds_selftest_bts_consistency(const struct bts_trace *trace)
{
int error = 0;
@@ -125,36 +133,32 @@ static int ds_selftest_bts_read(struct bts_tracer *tracer,
return 0;
}

-int ds_selftest_bts(void)
+static void ds_selftest_bts_cpu(void *arg)
{
+ struct ds_selftest_bts_conf *conf = arg;
const struct bts_trace *trace;
- struct bts_tracer *tracer;
- int error = 0;
void *top;
- unsigned char buffer[BUFFER_SIZE];

- printk(KERN_INFO "[ds] bts selftest...");
-
- tracer = ds_request_bts_cpu(smp_processor_id(), buffer, BUFFER_SIZE,
- NULL, (size_t)-1, BTS_KERNEL);
- if (IS_ERR(tracer)) {
- error = PTR_ERR(tracer);
- tracer = NULL;
+ if (IS_ERR(conf->tracer)) {
+ conf->error = PTR_ERR(conf->tracer);
+ conf->tracer = NULL;

printk(KERN_CONT
- "initialization failed (err: %d)...", error);
- goto out;
+ "initialization failed (err: %d)...", conf->error);
+ return;
}

- /* The return should already give us enough trace. */
- ds_suspend_bts(tracer);
+ /* We should meanwhile have enough trace. */
+ conf->error = conf->suspend(conf->tracer);
+ if (conf->error < 0)
+ return;

/* Let's see if we can access the trace. */
- trace = ds_read_bts(tracer);
+ trace = ds_read_bts(conf->tracer);

- error = ds_selftest_bts_consistency(trace);
- if (error < 0)
- goto out;
+ conf->error = ds_selftest_bts_consistency(trace);
+ if (conf->error < 0)
+ return;

/* If everything went well, we should have a few trace entries. */
if (trace->ds.top == trace->ds.begin) {
@@ -168,10 +172,11 @@ int ds_selftest_bts(void)
}

/* Let's try to read the trace we collected. */
- error = ds_selftest_bts_read(tracer, trace,
+ conf->error =
+ ds_selftest_bts_read(conf->tracer, trace,
trace->ds.begin, trace->ds.top);
- if (error < 0)
- goto out;
+ if (conf->error < 0)
+ return;

/*
* Let's read the trace again.
@@ -179,26 +184,31 @@ int ds_selftest_bts(void)
*/
top = trace->ds.top;

- trace = ds_read_bts(tracer);
- error = ds_selftest_bts_consistency(trace);
- if (error < 0)
- goto out;
+ trace = ds_read_bts(conf->tracer);
+ conf->error = ds_selftest_bts_consistency(trace);
+ if (conf->error < 0)
+ return;

if (top != trace->ds.top) {
printk(KERN_CONT "suspend not working...");
- error = -1;
- goto out;
+ conf->error = -1;
+ return;
}

/* Let's collect some more trace - see if resume is working. */
- ds_resume_bts(tracer);
- ds_suspend_bts(tracer);
+ conf->error = conf->resume(conf->tracer);
+ if (conf->error < 0)
+ return;
+
+ conf->error = conf->suspend(conf->tracer);
+ if (conf->error < 0)
+ return;

- trace = ds_read_bts(tracer);
+ trace = ds_read_bts(conf->tracer);

- error = ds_selftest_bts_consistency(trace);
- if (error < 0)
- goto out;
+ conf->error = ds_selftest_bts_consistency(trace);
+ if (conf->error < 0)
+ return;

if (trace->ds.top == top) {
/*
@@ -210,35 +220,113 @@ int ds_selftest_bts(void)
printk(KERN_CONT
"no resume progress/overflow...");

- error = ds_selftest_bts_read(tracer, trace,
+ conf->error =
+ ds_selftest_bts_read(conf->tracer, trace,
trace->ds.begin, trace->ds.end);
} else if (trace->ds.top < top) {
/*
* We had a buffer overflow - the entire buffer should
* contain trace records.
*/
- error = ds_selftest_bts_read(tracer, trace,
+ conf->error =
+ ds_selftest_bts_read(conf->tracer, trace,
trace->ds.begin, trace->ds.end);
} else {
/*
* It is quite likely that the buffer did not overflow.
* Let's just check the delta trace.
*/
- error = ds_selftest_bts_read(tracer, trace,
- top, trace->ds.top);
+ conf->error =
+ ds_selftest_bts_read(conf->tracer, trace, top,
+ trace->ds.top);
}
- if (error < 0)
- goto out;
+ if (conf->error < 0)
+ return;

- error = 0;
+ conf->error = 0;
+}

- /* The final test: release the tracer while tracing is suspended. */
- out:
- ds_release_bts(tracer);
+static int ds_suspend_bts_wrap(struct bts_tracer *tracer)
+{
+ ds_suspend_bts(tracer);
+ return 0;
+}
+
+static int ds_resume_bts_wrap(struct bts_tracer *tracer)
+{
+ ds_resume_bts(tracer);
+ return 0;
+}

- printk(KERN_CONT "%s.\n", (error ? "failed" : "passed"));
+static void ds_release_bts_noirq_wrap(void *tracer)
+{
+ (void)ds_release_bts_noirq(tracer);
+}

- return error;
+static int ds_selftest_bts_bad_release_noirq(int cpu,
+ struct bts_tracer *tracer)
+{
+ int error = -EPERM;
+
+ /* Try to release the tracer on the wrong cpu. */
+ get_cpu();
+ if (cpu != smp_processor_id()) {
+ error = ds_release_bts_noirq(tracer);
+ if (error != -EPERM)
+ printk(KERN_CONT "release on wrong cpu...");
+ }
+ put_cpu();
+
+ return error ? 0 : -1;
+}
+
+int ds_selftest_bts(void)
+{
+ struct ds_selftest_bts_conf conf;
+ unsigned char buffer[BUFFER_SIZE];
+ int cpu;
+
+ printk(KERN_INFO "[ds] bts selftest...");
+ conf.error = 0;
+
+ get_online_cpus();
+ for_each_online_cpu(cpu) {
+ conf.suspend = ds_suspend_bts_wrap;
+ conf.resume = ds_resume_bts_wrap;
+ conf.tracer =
+ ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
+ NULL, (size_t)-1, BTS_KERNEL);
+ ds_selftest_bts_cpu(&conf);
+ ds_release_bts(conf.tracer);
+ if (conf.error < 0)
+ goto out;
+
+ conf.suspend = ds_suspend_bts_noirq;
+ conf.resume = ds_resume_bts_noirq;
+ conf.tracer =
+ ds_request_bts_cpu(cpu, buffer, BUFFER_SIZE,
+ NULL, (size_t)-1, BTS_KERNEL);
+ smp_call_function_single(cpu, ds_selftest_bts_cpu, &conf, 1);
+ if (conf.error >= 0) {
+ conf.error =
+ ds_selftest_bts_bad_release_noirq(cpu,
+ conf.tracer);
+ /* We must not release the tracer twice. */
+ if (conf.error < 0)
+ conf.tracer = NULL;
+ }
+ smp_call_function_single(cpu, ds_release_bts_noirq_wrap,
+ conf.tracer, 1);
+ if (conf.error < 0)
+ goto out;
+ }
+
+ conf.error = 0;
+ out:
+ put_online_cpus();
+ printk(KERN_CONT "%s.\n", (conf.error ? "failed" : "passed"));
+
+ return conf.error;
}

int ds_selftest_pebs(void)

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