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Revert "Oprofile Multiplexing Patch"
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Reverting commit 1a960b4 for the main
branch. Multiplexing will be tracked on a separate feature branch.

Conflicts:

    arch/x86/oprofile/nmi_int.c
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Robert Richter committed Sep 24, 2008
1 parent 45f197a commit 4c168ea
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Showing 10 changed files with 45 additions and 247 deletions.
100 changes: 8 additions & 92 deletions arch/x86/oprofile/nmi_int.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -191,19 +144,20 @@ 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);
if (!per_cpu(cpu_msrs, i).counters) {
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;
Expand Down Expand Up @@ -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
*/

Expand All @@ -264,48 +217,15 @@ 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);
nmi_enabled = 1;
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;
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down
3 changes: 1 addition & 2 deletions arch/x86/oprofile/op_counter.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down
76 changes: 30 additions & 46 deletions arch/x86/oprofile/op_model_amd.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand All @@ -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)
Expand All @@ -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

Expand Down Expand Up @@ -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;
}
Expand All @@ -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);
Expand All @@ -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;
}
}
}
Expand Down Expand Up @@ -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);
}
}

Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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);
}
Expand Down Expand Up @@ -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,
Expand Down
4 changes: 0 additions & 4 deletions arch/x86/oprofile/op_model_p4.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand All @@ -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,
Expand Down
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