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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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      Last update: 2009-05-07 11:31    [W:0.040 / U:0.564 seconds]
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