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    Subject[PATCH 09/10] x86: oprofile: remove NR_CPUS arrays in arch/x86/oprofile/nmi_int.c
    Change the following arrays sized by NR_CPUS to be PERCPU variables:

    static struct op_msrs cpu_msrs[NR_CPUS];
    static unsigned long saved_lvtpc[NR_CPUS];

    Also some minor complaints from checkpatch.pl fixed.

    Based on:
    git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

    Cc: Philippe Elie <phil.el@wanadoo.fr>

    Signed-off-by: Mike Travis <travis@sgi.com>
    ---

    All changes were transparent except for:

    static void nmi_shutdown(void)
    {
    + struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
    nmi_enabled = 0;
    on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
    unregister_die_notifier(&profile_exceptions_nb);
    - model->shutdown(cpu_msrs);
    + model->shutdown(msrs);
    free_msrs();
    }

    The existing code passed a reference to cpu 0's instance of struct op_msrs
    to model->shutdown, whilst the other functions are passed a reference to
    <this cpu's> instance of a struct op_msrs. This seemed to be a bug to me
    even though as long as cpu 0 and <this cpu> are of the same type it would
    have the same effect...?
    ---
    arch/x86/oprofile/nmi_int.c | 49 ++++++++++++++++++++++++--------------------
    1 file changed, 27 insertions(+), 22 deletions(-)

    --- linux.trees.git.orig/arch/x86/oprofile/nmi_int.c
    +++ linux.trees.git/arch/x86/oprofile/nmi_int.c
    @@ -23,8 +23,8 @@
    #include "op_x86_model.h"

    static struct op_x86_model_spec const *model;
    -static struct op_msrs cpu_msrs[NR_CPUS];
    -static unsigned long saved_lvtpc[NR_CPUS];
    +static DEFINE_PER_CPU(struct op_msrs, cpu_msrs);
    +static DEFINE_PER_CPU(unsigned long, saved_lvtpc);

    static int nmi_start(void);
    static void nmi_stop(void);
    @@ -89,7 +89,7 @@ static int profile_exceptions_notify(str

    switch (val) {
    case DIE_NMI:
    - if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))
    + if (model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu)))
    ret = NOTIFY_STOP;
    break;
    default:
    @@ -126,7 +126,7 @@ static void nmi_cpu_save_registers(struc
    static void nmi_save_registers(void *dummy)
    {
    int cpu = smp_processor_id();
    - struct op_msrs *msrs = &cpu_msrs[cpu];
    + struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
    nmi_cpu_save_registers(msrs);
    }

    @@ -134,10 +134,10 @@ static void free_msrs(void)
    {
    int i;
    for_each_possible_cpu(i) {
    - kfree(cpu_msrs[i].counters);
    - cpu_msrs[i].counters = NULL;
    - kfree(cpu_msrs[i].controls);
    - cpu_msrs[i].controls = NULL;
    + kfree(per_cpu(cpu_msrs, i).counters);
    + per_cpu(cpu_msrs, i).counters = NULL;
    + kfree(per_cpu(cpu_msrs, i).controls);
    + per_cpu(cpu_msrs, i).controls = NULL;
    }
    }

    @@ -149,13 +149,15 @@ static int allocate_msrs(void)

    int i;
    for_each_possible_cpu(i) {
    - cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
    - if (!cpu_msrs[i].counters) {
    + per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
    + GFP_KERNEL);
    + if (!per_cpu(cpu_msrs, i).counters) {
    success = 0;
    break;
    }
    - cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
    - if (!cpu_msrs[i].controls) {
    + per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
    + GFP_KERNEL);
    + if (!per_cpu(cpu_msrs, i).controls) {
    success = 0;
    break;
    }
    @@ -170,11 +172,11 @@ static int allocate_msrs(void)
    static void nmi_cpu_setup(void *dummy)
    {
    int cpu = smp_processor_id();
    - struct op_msrs *msrs = &cpu_msrs[cpu];
    + struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
    spin_lock(&oprofilefs_lock);
    model->setup_ctrs(msrs);
    spin_unlock(&oprofilefs_lock);
    - saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
    + per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
    apic_write(APIC_LVTPC, APIC_DM_NMI);
    }

    @@ -203,13 +205,15 @@ static int nmi_setup(void)
    */

    /* Assume saved/restored counters are the same on all CPUs */
    - model->fill_in_addresses(&cpu_msrs[0]);
    + model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
    for_each_possible_cpu(cpu) {
    if (cpu != 0) {
    - memcpy(cpu_msrs[cpu].counters, cpu_msrs[0].counters,
    + memcpy(per_cpu(cpu_msrs, cpu).counters,
    + per_cpu(cpu_msrs, 0).counters,
    sizeof(struct op_msr) * model->num_counters);

    - memcpy(cpu_msrs[cpu].controls, cpu_msrs[0].controls,
    + memcpy(per_cpu(cpu_msrs, cpu).controls,
    + per_cpu(cpu_msrs, 0).controls,
    sizeof(struct op_msr) * model->num_controls);
    }

    @@ -249,7 +253,7 @@ static void nmi_cpu_shutdown(void *dummy
    {
    unsigned int v;
    int cpu = smp_processor_id();
    - struct op_msrs *msrs = &cpu_msrs[cpu];
    + struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);

    /* restoring APIC_LVTPC can trigger an apic error because the delivery
    * mode and vector nr combination can be illegal. That's by design: on
    @@ -258,23 +262,24 @@ static void nmi_cpu_shutdown(void *dummy
    */
    v = apic_read(APIC_LVTERR);
    apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
    - apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
    + apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
    apic_write(APIC_LVTERR, v);
    nmi_restore_registers(msrs);
    }

    static void nmi_shutdown(void)
    {
    + struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
    nmi_enabled = 0;
    on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
    unregister_die_notifier(&profile_exceptions_nb);
    - model->shutdown(cpu_msrs);
    + model->shutdown(msrs);
    free_msrs();
    }

    static void nmi_cpu_start(void *dummy)
    {
    - struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
    + struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
    model->start(msrs);
    }

    @@ -286,7 +291,7 @@ static int nmi_start(void)

    static void nmi_cpu_stop(void *dummy)
    {
    - struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
    + struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
    model->stop(msrs);
    }

    --


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