Revert "Oprofile Multiplexing Patch"

Reverting commit 1a960b402a51d80abf54e3f8e4972374ffe5f22d for the main
branch. Multiplexing will be tracked on a separate feature branch.

Conflicts:

    arch/x86/oprofile/nmi_int.c

1 files changed, 8 insertions, 92 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 4108d02c5292..287513a09819 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -23,18 +23,12 @@
 #include "op_counter.h"
 #include "op_x86_model.h"
 
-DEFINE_PER_CPU(int, switch_index);
-
 static struct op_x86_model_spec const *model;
 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);
-static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs);
-static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs);
-static void nmi_cpu_stop(void *dummy);
-static void nmi_cpu_start(void *dummy);
 
 /* 0 == registered but off, 1 == registered and on */
 static int nmi_enabled = 0;
@@ -87,47 +81,6 @@ static void exit_sysfs(void)
 #define exit_sysfs() do { } while (0)
 #endif /* CONFIG_PM */
 
-static void nmi_cpu_switch(void *dummy)
-{
-        int cpu = smp_processor_id();
-        int si = per_cpu(switch_index, cpu);
-        struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
-
-        nmi_cpu_stop(NULL);
-        nmi_cpu_save_mpx_registers(msrs);
-
-        /* move to next set */
-        si += model->num_hardware_counters;
-        if ((si > model->num_counters) || (counter_config[si].count == 0))
-                per_cpu(switch_index, smp_processor_id()) = 0;
-        else
-                per_cpu(switch_index, smp_processor_id()) = si;
-
-        nmi_cpu_restore_mpx_registers(msrs);
-        model->setup_ctrs(msrs);
-        nmi_cpu_start(NULL);
-}
-
-/*
- * Quick check to see if multiplexing is necessary.
- * The check should be sufficient since counters are used
- * in ordre.
- */
-static int nmi_multiplex_on(void)
-{
-        return counter_config[model->num_hardware_counters].count ? 0 : -EINVAL;
-}
-
-static int nmi_switch_event(void)
-{
-        if (nmi_multiplex_on() < 0)
-                return -EINVAL;
-
-        on_each_cpu(nmi_cpu_switch, NULL, 1);
-
-        return 0;
-}
-
 static int profile_exceptions_notify(struct notifier_block *self,
                                      unsigned long val, void *data)
 {
@@ -191,10 +144,11 @@ static void free_msrs(void)
 
 static int allocate_msrs(void)
 {
-        int i, success = 1;
+        int success = 1;
         size_t controls_size = sizeof(struct op_msr) * model->num_controls;
         size_t counters_size = sizeof(struct op_msr) * model->num_counters;
 
+        int i;
         for_each_possible_cpu(i) {
                 per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
                                                                 GFP_KERNEL);
@@ -202,8 +156,8 @@ static int allocate_msrs(void)
                         success = 0;
                         break;
                 }
-                per_cpu(cpu_msrs, i).controls =
-                                kmalloc(controls_size, GFP_KERNEL);
+                per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
+                                                                GFP_KERNEL);
                 if (!per_cpu(cpu_msrs, i).controls) {
                         success = 0;
                         break;
@@ -247,8 +201,7 @@ static int nmi_setup(void)
                 return err;
         }
 
-        /*
-         * We need to serialize save and setup for HT because the subset
+        /* We need to serialize save and setup for HT because the subset
          * of msrs are distinct for save and setup operations
          */
 
@@ -264,6 +217,7 @@ static int nmi_setup(void)
                                 per_cpu(cpu_msrs, 0).controls,
                                 sizeof(struct op_msr) * model->num_controls);
                 }
+
         }
         on_each_cpu(nmi_save_registers, NULL, 1);
         on_each_cpu(nmi_cpu_setup, NULL, 1);
@@ -271,41 +225,7 @@ static int nmi_setup(void)
         return 0;
 }
 
-static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
-{
-        unsigned int si = __get_cpu_var(switch_index);
-        unsigned int const nr_ctrs = model->num_hardware_counters;
-        struct op_msr *counters = &msrs->counters[si];
-        unsigned int i;
-
-        for (i = 0; i < nr_ctrs; ++i) {
-                int offset = i + si;
-                if (counters[offset].addr) {
-                        rdmsr(counters[offset].addr,
-                                counters[offset].multiplex.low,
-                                counters[offset].multiplex.high);
-                }
-        }
-}
-
-static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
-{
-        unsigned int si = __get_cpu_var(switch_index);
-        unsigned int const nr_ctrs = model->num_hardware_counters;
-        struct op_msr *counters = &msrs->counters[si];
-        unsigned int i;
-
-        for (i = 0; i < nr_ctrs; ++i) {
-                int offset = i + si;
-                if (counters[offset].addr) {
-                        wrmsr(counters[offset].addr,
-                                counters[offset].multiplex.low,
-                                counters[offset].multiplex.high);
-                }
-        }
-}
-
-static void nmi_cpu_restore_registers(struct op_msrs *msrs)
+static void nmi_restore_registers(struct op_msrs *msrs)
 {
         unsigned int const nr_ctrs = model->num_counters;
         unsigned int const nr_ctrls = model->num_controls;
@@ -345,8 +265,7 @@ static void nmi_cpu_shutdown(void *dummy)
         apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
         apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
         apic_write(APIC_LVTERR, v);
-        nmi_cpu_restore_registers(msrs);
-        __get_cpu_var(switch_index) = 0;
+        nmi_restore_registers(msrs);
 }
 
 static void nmi_shutdown(void)
@@ -409,7 +328,6 @@ static int nmi_create_files(struct super_block *sb, struct dentry *root)
                 oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
                 oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
                 oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
-                counter_config[i].save_count_low = 0;
         }
 
         return 0;
@@ -551,14 +469,12 @@ int __init op_nmi_init(struct oprofile_operations *ops)
         }
 
         /* default values, can be overwritten by model */
-        __raw_get_cpu_var(switch_index) = 0;
         ops->create_files = nmi_create_files;
         ops->setup = nmi_setup;
         ops->shutdown = nmi_shutdown;
         ops->start = nmi_start;
         ops->stop = nmi_stop;
         ops->cpu_type = cpu_type;
-        ops->switch_events = nmi_switch_event;
 
         if (model->init)
                 ret = model->init(ops);