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

6 files changed, 39 insertions, 149 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);
diff --git a/arch/x86/oprofile/op_counter.h b/arch/x86/oprofile/op_counter.h
index 786d6e01cf7f..2880b15c4675 100644
--- a/arch/x86/oprofile/op_counter.h
+++ b/arch/x86/oprofile/op_counter.h
@@ -10,14 +10,13 @@
 #ifndef OP_COUNTER_H
 #define OP_COUNTER_H
  
-#define OP_MAX_COUNTER 32
+#define OP_MAX_COUNTER 8
  
 /* Per-perfctr configuration as set via
  * oprofilefs.
  */
 struct op_counter_config {
         unsigned long count;
-                unsigned long save_count_low;
         unsigned long enabled;
         unsigned long event;
         unsigned long kernel;
diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index bbf2b68bcc5d..d9faf607b3a6 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -15,7 +15,6 @@
 #include <linux/oprofile.h>
 #include <linux/device.h>
 #include <linux/pci.h>
-#include <linux/percpu.h>
 
 #include <asm/ptrace.h>
 #include <asm/msr.h>
@@ -24,10 +23,8 @@
 #include "op_x86_model.h"
 #include "op_counter.h"
 
-#define NUM_COUNTERS 32
-#define NUM_HARDWARE_COUNTERS 4
-#define NUM_CONTROLS 32
-#define NUM_HARDWARE_CONTROLS 4
+#define NUM_COUNTERS 4
+#define NUM_CONTROLS 4
 
 #define CTR_IS_RESERVED(msrs, c) (msrs->counters[(c)].addr ? 1 : 0)
 #define CTR_READ(l, h, msrs, c) do {rdmsr(msrs->counters[(c)].addr, (l), (h)); } while (0)
@@ -51,7 +48,6 @@
 #define CTRL_SET_GUEST_ONLY(val, h) (val |= ((h & 1) << 8))
 
 static unsigned long reset_value[NUM_COUNTERS];
-DECLARE_PER_CPU(int, switch_index);
 
 #ifdef CONFIG_OPROFILE_IBS
 
@@ -134,17 +130,15 @@ static void op_amd_fill_in_addresses(struct op_msrs * const msrs)
         int i;
 
         for (i = 0; i < NUM_COUNTERS; i++) {
-                int hw_counter = i % NUM_HARDWARE_COUNTERS;
-                if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + hw_counter))
-                        msrs->counters[i].addr = MSR_K7_PERFCTR0 + hw_counter;
+                if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
+                        msrs->counters[i].addr = MSR_K7_PERFCTR0 + i;
                 else
                         msrs->counters[i].addr = 0;
         }
 
         for (i = 0; i < NUM_CONTROLS; i++) {
-                int hw_control = i % NUM_HARDWARE_CONTROLS;
-                if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + hw_control))
-                        msrs->controls[i].addr = MSR_K7_EVNTSEL0 + hw_control;
+                if (reserve_evntsel_nmi(MSR_K7_EVNTSEL0 + i))
+                        msrs->controls[i].addr = MSR_K7_EVNTSEL0 + i;
                 else
                         msrs->controls[i].addr = 0;
         }
@@ -156,16 +150,8 @@ static void op_amd_setup_ctrs(struct op_msrs const * const msrs)
         unsigned int low, high;
         int i;
 
-        for (i = 0; i < NUM_HARDWARE_CONTROLS; ++i) {
-                int offset = i + __get_cpu_var(switch_index);
-                if (counter_config[offset].enabled)
-                        reset_value[offset] = counter_config[offset].count;
-                else
-                        reset_value[offset] = 0;
-        }
-
         /* clear all counters */
-        for (i = 0 ; i < NUM_HARDWARE_CONTROLS; ++i) {
+        for (i = 0 ; i < NUM_CONTROLS; ++i) {
                 if (unlikely(!CTRL_IS_RESERVED(msrs, i)))
                         continue;
                 CTRL_READ(low, high, msrs, i);
@@ -175,31 +161,34 @@ static void op_amd_setup_ctrs(struct op_msrs const * const msrs)
         }
 
         /* avoid a false detection of ctr overflows in NMI handler */
-        for (i = 0; i < NUM_HARDWARE_COUNTERS; ++i) {
+        for (i = 0; i < NUM_COUNTERS; ++i) {
                 if (unlikely(!CTR_IS_RESERVED(msrs, i)))
                         continue;
                 CTR_WRITE(1, msrs, i);
         }
 
         /* enable active counters */
-        for (i = 0; i < NUM_HARDWARE_COUNTERS; ++i) {
-                int offset = i + __get_cpu_var(switch_index);
-                if ((counter_config[offset].enabled) && (CTR_IS_RESERVED(msrs, i))) {
-                        CTR_WRITE(counter_config[offset].count, msrs, i);
+        for (i = 0; i < NUM_COUNTERS; ++i) {
+                if ((counter_config[i].enabled) && (CTR_IS_RESERVED(msrs, i))) {
+                        reset_value[i] = counter_config[i].count;
+
+                        CTR_WRITE(counter_config[i].count, msrs, i);
 
                         CTRL_READ(low, high, msrs, i);
                         CTRL_CLEAR_LO(low);
                         CTRL_CLEAR_HI(high);
                         CTRL_SET_ENABLE(low);
-                        CTRL_SET_USR(low, counter_config[offset].user);
-                        CTRL_SET_KERN(low, counter_config[offset].kernel);
-                        CTRL_SET_UM(low, counter_config[offset].unit_mask);
-                        CTRL_SET_EVENT_LOW(low, counter_config[offset].event);
-                        CTRL_SET_EVENT_HIGH(high, counter_config[offset].event);
+                        CTRL_SET_USR(low, counter_config[i].user);
+                        CTRL_SET_KERN(low, counter_config[i].kernel);
+                        CTRL_SET_UM(low, counter_config[i].unit_mask);
+                        CTRL_SET_EVENT_LOW(low, counter_config[i].event);
+                        CTRL_SET_EVENT_HIGH(high, counter_config[i].event);
                         CTRL_SET_HOST_ONLY(high, 0);
                         CTRL_SET_GUEST_ONLY(high, 0);
 
                         CTRL_WRITE(low, high, msrs, i);
+                } else {
+                        reset_value[i] = 0;
                 }
         }
 }
@@ -287,14 +276,13 @@ static int op_amd_check_ctrs(struct pt_regs * const regs,
         unsigned int low, high;
         int i;
 
-        for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) {
-                int offset = i + __get_cpu_var(switch_index);
-                if (!reset_value[offset])
+        for (i = 0 ; i < NUM_COUNTERS; ++i) {
+                if (!reset_value[i])
                         continue;
                 CTR_READ(low, high, msrs, i);
                 if (CTR_OVERFLOWED(low)) {
-                        oprofile_add_sample(regs, offset);
-                        CTR_WRITE(reset_value[offset], msrs, i);
+                        oprofile_add_sample(regs, i);
+                        CTR_WRITE(reset_value[i], msrs, i);
                 }
         }
 
@@ -310,10 +298,8 @@ static void op_amd_start(struct op_msrs const * const msrs)
 {
         unsigned int low, high;
         int i;
-
-        for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) {
-                int offset = i + __get_cpu_var(switch_index);
-                if (reset_value[offset]) {
+        for (i = 0 ; i < NUM_COUNTERS ; ++i) {
+                if (reset_value[i]) {
                         CTRL_READ(low, high, msrs, i);
                         CTRL_SET_ACTIVE(low);
                         CTRL_WRITE(low, high, msrs, i);
@@ -343,8 +329,8 @@ static void op_amd_stop(struct op_msrs const * const msrs)
 
         /* Subtle: stop on all counters to avoid race with
          * setting our pm callback */
-        for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) {
-                if (!reset_value[i + per_cpu(switch_index, smp_processor_id())])
+        for (i = 0 ; i < NUM_COUNTERS ; ++i) {
+                if (!reset_value[i])
                         continue;
                 CTRL_READ(low, high, msrs, i);
                 CTRL_SET_INACTIVE(low);
@@ -370,11 +356,11 @@ static void op_amd_shutdown(struct op_msrs const * const msrs)
 {
         int i;
 
-        for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) {
+        for (i = 0 ; i < NUM_COUNTERS ; ++i) {
                 if (CTR_IS_RESERVED(msrs, i))
                         release_perfctr_nmi(MSR_K7_PERFCTR0 + i);
         }
-        for (i = 0 ; i < NUM_HARDWARE_COUNTERS ; ++i) {
+        for (i = 0 ; i < NUM_CONTROLS ; ++i) {
                 if (CTRL_IS_RESERVED(msrs, i))
                         release_evntsel_nmi(MSR_K7_EVNTSEL0 + i);
         }
@@ -548,8 +534,6 @@ struct op_x86_model_spec const op_amd_spec = {
         .exit = op_amd_exit,
         .num_counters = NUM_COUNTERS,
         .num_controls = NUM_CONTROLS,
-        .num_hardware_counters = NUM_HARDWARE_COUNTERS,
-        .num_hardware_controls = NUM_HARDWARE_CONTROLS,
         .fill_in_addresses = &op_amd_fill_in_addresses,
         .setup_ctrs = &op_amd_setup_ctrs,
         .check_ctrs = &op_amd_check_ctrs,
diff --git a/arch/x86/oprofile/op_model_p4.c b/arch/x86/oprofile/op_model_p4.c
index cacba61ffbac..43ac5af338d8 100644
--- a/arch/x86/oprofile/op_model_p4.c
+++ b/arch/x86/oprofile/op_model_p4.c
@@ -700,8 +700,6 @@ static void p4_shutdown(struct op_msrs const * const msrs)
 struct op_x86_model_spec const op_p4_ht2_spec = {
         .num_counters = NUM_COUNTERS_HT2,
         .num_controls = NUM_CONTROLS_HT2,
-        .num_hardware_counters = NUM_COUNTERS_HT2,
-        .num_hardware_controls = NUM_CONTROLS_HT2,
         .fill_in_addresses = &p4_fill_in_addresses,
         .setup_ctrs = &p4_setup_ctrs,
         .check_ctrs = &p4_check_ctrs,
@@ -714,8 +712,6 @@ struct op_x86_model_spec const op_p4_ht2_spec = {
 struct op_x86_model_spec const op_p4_spec = {
         .num_counters = NUM_COUNTERS_NON_HT,
         .num_controls = NUM_CONTROLS_NON_HT,
-        .num_hardware_counters = NUM_COUNTERS_NON_HT,
-        .num_hardware_controls = NUM_CONTROLS_NON_HT,
         .fill_in_addresses = &p4_fill_in_addresses,
         .setup_ctrs = &p4_setup_ctrs,
         .check_ctrs = &p4_check_ctrs,
diff --git a/arch/x86/oprofile/op_model_ppro.c b/arch/x86/oprofile/op_model_ppro.c
index e5811aa480eb..eff431f6c57b 100644
--- a/arch/x86/oprofile/op_model_ppro.c
+++ b/arch/x86/oprofile/op_model_ppro.c
@@ -183,8 +183,6 @@ static void ppro_shutdown(struct op_msrs const * const msrs)
 struct op_x86_model_spec const op_ppro_spec = {
         .num_counters = NUM_COUNTERS,
         .num_controls = NUM_CONTROLS,
-        .num_hardware_counters = NUM_COUNTERS,
-        .num_hardware_controls = NUM_CONTROLS,
         .fill_in_addresses = &ppro_fill_in_addresses,
         .setup_ctrs = &ppro_setup_ctrs,
         .check_ctrs = &ppro_check_ctrs,
diff --git a/arch/x86/oprofile/op_x86_model.h b/arch/x86/oprofile/op_x86_model.h
index e07ba1076371..05a0261ba0c3 100644
--- a/arch/x86/oprofile/op_x86_model.h
+++ b/arch/x86/oprofile/op_x86_model.h
@@ -19,7 +19,6 @@ struct op_saved_msr {
 struct op_msr {
         unsigned long addr;
         struct op_saved_msr saved;
-        struct op_saved_msr multiplex;
 };
 
 struct op_msrs {
@@ -35,8 +34,6 @@ struct pt_regs;
 struct op_x86_model_spec {
         int (*init)(struct oprofile_operations *ops);
         void (*exit)(void);
-        unsigned int const num_hardware_counters;
-        unsigned int const num_hardware_controls;
         unsigned int const num_counters;
         unsigned int const num_controls;
         void (*fill_in_addresses)(struct op_msrs * const msrs);