[PATCH 1/3] x86: Use this_cpu_ops to optimize code

From: Tejun Heo
Date: Sat Dec 18 2010 - 10:29:05 EST

Go through x86 code and replace __get_cpu_var and get_cpu_var
instances that refer to a scalar and are not used for address
determinations.

Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
---
Peter, these three patches are the x86 ones which were in
percpu#for-next but should go through x86 tree. These should be
applied on top of percpu#this_cpu_ops.

Thank you.

arch/x86/include/asm/debugreg.h | 2 +-
arch/x86/kernel/apic/io_apic.c | 4 ++--
arch/x86/kernel/apic/nmi.c | 24 ++++++++++++------------
arch/x86/kernel/apic/x2apic_uv_x.c | 8 ++++----
arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 2 +-
arch/x86/kernel/cpu/mcheck/mce.c | 6 +++---
arch/x86/kernel/cpu/perf_event.c | 27 +++++++++++----------------
arch/x86/kernel/cpu/perf_event_intel.c | 4 ++--
arch/x86/kernel/ftrace.c | 6 +++---
arch/x86/kernel/hw_breakpoint.c | 12 ++++++------
arch/x86/kernel/irq.c | 6 +++---
arch/x86/kernel/irq_32.c | 4 ++--
arch/x86/kernel/smpboot.c | 2 +-
arch/x86/kernel/tsc.c | 2 +-
arch/x86/kvm/x86.c | 8 ++++----
arch/x86/oprofile/nmi_int.c | 2 +-
16 files changed, 57 insertions(+), 62 deletions(-)

diff --git a/arch/x86/include/asm/debugreg.h b/arch/x86/include/asm/debugreg.h
index b81002f..078ad0c 100644
--- a/arch/x86/include/asm/debugreg.h
+++ b/arch/x86/include/asm/debugreg.h
@@ -94,7 +94,7 @@ static inline void hw_breakpoint_disable(void)

static inline int hw_breakpoint_active(void)
{
- return __get_cpu_var(cpu_dr7) & DR_GLOBAL_ENABLE_MASK;
+ return __this_cpu_read(cpu_dr7) & DR_GLOBAL_ENABLE_MASK;
}

extern void aout_dump_debugregs(struct user *dump);
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 7cc0a72..8d50922 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2302,7 +2302,7 @@ asmlinkage void smp_irq_move_cleanup_interrupt(void)
unsigned int irr;
struct irq_desc *desc;
struct irq_cfg *cfg;
- irq = __get_cpu_var(vector_irq)[vector];
+ irq = __this_cpu_read(vector_irq[vector]);

if (irq == -1)
continue;
@@ -2336,7 +2336,7 @@ asmlinkage void smp_irq_move_cleanup_interrupt(void)
apic->send_IPI_self(IRQ_MOVE_CLEANUP_VECTOR);
goto unlock;
}
- __get_cpu_var(vector_irq)[vector] = -1;
+ __this_cpu_write(vector_irq[vector], -1);
unlock:
raw_spin_unlock(&desc->lock);
}
diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
index c90041c..b387dce 100644
--- a/arch/x86/kernel/apic/nmi.c
+++ b/arch/x86/kernel/apic/nmi.c
@@ -306,12 +306,12 @@ void acpi_nmi_disable(void)
*/
void cpu_nmi_set_wd_enabled(void)
{
- __get_cpu_var(wd_enabled) = 1;
+ __this_cpu_write(wd_enabled, 1);
}

void setup_apic_nmi_watchdog(void *unused)
{
- if (__get_cpu_var(wd_enabled))
+ if (__this_cpu_read(wd_enabled))
return;

/* cheap hack to support suspend/resume */
@@ -322,12 +322,12 @@ void setup_apic_nmi_watchdog(void *unused)
switch (nmi_watchdog) {
case NMI_LOCAL_APIC:
if (lapic_watchdog_init(nmi_hz) < 0) {
- __get_cpu_var(wd_enabled) = 0;
+ __this_cpu_write(wd_enabled, 0);
return;
}
/* FALL THROUGH */
case NMI_IO_APIC:
- __get_cpu_var(wd_enabled) = 1;
+ __this_cpu_write(wd_enabled, 1);
atomic_inc(&nmi_active);
}
}
@@ -337,13 +337,13 @@ void stop_apic_nmi_watchdog(void *unused)
/* only support LOCAL and IO APICs for now */
if (!nmi_watchdog_active())
return;
- if (__get_cpu_var(wd_enabled) == 0)
+ if (__this_cpu_read(wd_enabled) == 0)
return;
if (nmi_watchdog == NMI_LOCAL_APIC)
lapic_watchdog_stop();
else
__acpi_nmi_disable(NULL);
- __get_cpu_var(wd_enabled) = 0;
+ __this_cpu_write(wd_enabled, 0);
atomic_dec(&nmi_active);
}

@@ -403,8 +403,8 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)

sum = get_timer_irqs(cpu);

- if (__get_cpu_var(nmi_touch)) {
- __get_cpu_var(nmi_touch) = 0;
+ if (__this_cpu_read(nmi_touch)) {
+ __this_cpu_write(nmi_touch, 0);
touched = 1;
}

@@ -427,7 +427,7 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
touched = 1;

/* if the none of the timers isn't firing, this cpu isn't doing much */
- if (!touched && __get_cpu_var(last_irq_sum) == sum) {
+ if (!touched && __this_cpu_read(last_irq_sum) == sum) {
/*
* Ayiee, looks like this CPU is stuck ...
* wait a few IRQs (5 seconds) before doing the oops ...
@@ -440,12 +440,12 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
die_nmi("BUG: NMI Watchdog detected LOCKUP",
regs, panic_on_timeout);
} else {
- __get_cpu_var(last_irq_sum) = sum;
+ __this_cpu_write(last_irq_sum, sum);
__this_cpu_write(alert_counter, 0);
}

/* see if the nmi watchdog went off */
- if (!__get_cpu_var(wd_enabled))
+ if (!__this_cpu_read(wd_enabled))
return rc;
switch (nmi_watchdog) {
case NMI_LOCAL_APIC:
@@ -467,7 +467,7 @@ nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)

static void enable_ioapic_nmi_watchdog_single(void *unused)
{
- __get_cpu_var(wd_enabled) = 1;
+ __this_cpu_write(wd_enabled, 1);
atomic_inc(&nmi_active);
__acpi_nmi_enable(NULL);
}
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index c1c52c3..26ec9a7 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -118,8 +118,8 @@ static int __init uv_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
else if (!strcmp(oem_table_id, "UVX"))
uv_system_type = UV_X2APIC;
else if (!strcmp(oem_table_id, "UVH")) {
- __get_cpu_var(x2apic_extra_bits) =
- nodeid << (uvh_apicid.s.pnode_shift - 1);
+ __this_cpu_write(x2apic_extra_bits,
+ nodeid << (uvh_apicid.s.pnode_shift - 1));
uv_system_type = UV_NON_UNIQUE_APIC;
uv_set_apicid_hibit();
return 1;
@@ -284,7 +284,7 @@ static unsigned int x2apic_get_apic_id(unsigned long x)
unsigned int id;

WARN_ON(preemptible() && num_online_cpus() > 1);
- id = x | __get_cpu_var(x2apic_extra_bits);
+ id = x | __this_cpu_read(x2apic_extra_bits);

return id;
}
@@ -376,7 +376,7 @@ struct apic __refdata apic_x2apic_uv_x = {

static __cpuinit void set_x2apic_extra_bits(int pnode)
{
- __get_cpu_var(x2apic_extra_bits) = (pnode << 6);
+ __this_cpu_write(x2apic_extra_bits, (pnode << 6));
}

/*
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 491977b..42a3604 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -1377,7 +1377,7 @@ static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
static void query_values_on_cpu(void *_err)
{
int *err = _err;
- struct powernow_k8_data *data = __get_cpu_var(powernow_data);
+ struct powernow_k8_data *data = __this_cpu_read(powernow_data);

*err = query_current_values_with_pending_wait(data);
}
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 7a35b72..0c746af 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -326,7 +326,7 @@ static void mce_panic(char *msg, struct mce *final, char *exp)

static int msr_to_offset(u32 msr)
{
- unsigned bank = __get_cpu_var(injectm.bank);
+ unsigned bank = __this_cpu_read(injectm.bank);

if (msr == rip_msr)
return offsetof(struct mce, ip);
@@ -346,7 +346,7 @@ static u64 mce_rdmsrl(u32 msr)
{
u64 v;

- if (__get_cpu_var(injectm).finished) {
+ if (__this_cpu_read(injectm.finished)) {
int offset = msr_to_offset(msr);

if (offset < 0)
@@ -369,7 +369,7 @@ static u64 mce_rdmsrl(u32 msr)

static void mce_wrmsrl(u32 msr, u64 v)
{
- if (__get_cpu_var(injectm).finished) {
+ if (__this_cpu_read(injectm.finished)) {
int offset = msr_to_offset(msr);

if (offset >= 0)
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 6d75b91..ba85814 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -968,8 +968,7 @@ x86_perf_event_set_period(struct perf_event *event)

static void x86_pmu_enable_event(struct perf_event *event)
{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
- if (cpuc->enabled)
+ if (__this_cpu_read(cpu_hw_events.enabled))
__x86_pmu_enable_event(&event->hw,
ARCH_PERFMON_EVENTSEL_ENABLE);
}
@@ -1243,7 +1242,7 @@ perf_event_nmi_handler(struct notifier_block *self,
break;
case DIE_NMIUNKNOWN:
this_nmi = percpu_read(irq_stat.__nmi_count);
- if (this_nmi != __get_cpu_var(pmu_nmi).marked)
+ if (this_nmi != __this_cpu_read(pmu_nmi.marked))
/* let the kernel handle the unknown nmi */
return NOTIFY_DONE;
/*
@@ -1267,8 +1266,8 @@ perf_event_nmi_handler(struct notifier_block *self,
this_nmi = percpu_read(irq_stat.__nmi_count);
if ((handled > 1) ||
/* the next nmi could be a back-to-back nmi */
- ((__get_cpu_var(pmu_nmi).marked == this_nmi) &&
- (__get_cpu_var(pmu_nmi).handled > 1))) {
+ ((__this_cpu_read(pmu_nmi.marked) == this_nmi) &&
+ (__this_cpu_read(pmu_nmi.handled) > 1))) {
/*
* We could have two subsequent back-to-back nmis: The
* first handles more than one counter, the 2nd
@@ -1279,8 +1278,8 @@ perf_event_nmi_handler(struct notifier_block *self,
* handling more than one counter. We will mark the
* next (3rd) and then drop it if unhandled.
*/
- __get_cpu_var(pmu_nmi).marked = this_nmi + 1;
- __get_cpu_var(pmu_nmi).handled = handled;
+ __this_cpu_write(pmu_nmi.marked, this_nmi + 1);
+ __this_cpu_write(pmu_nmi.handled, handled);
}

return NOTIFY_STOP;
@@ -1454,11 +1453,9 @@ static inline void x86_pmu_read(struct perf_event *event)
*/
static void x86_pmu_start_txn(struct pmu *pmu)
{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-
perf_pmu_disable(pmu);
- cpuc->group_flag |= PERF_EVENT_TXN;
- cpuc->n_txn = 0;
+ __this_cpu_or(cpu_hw_events.group_flag, PERF_EVENT_TXN);
+ __this_cpu_write(cpu_hw_events.n_txn, 0);
}

/*
@@ -1468,14 +1465,12 @@ static void x86_pmu_start_txn(struct pmu *pmu)
*/
static void x86_pmu_cancel_txn(struct pmu *pmu)
{
- struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
-
- cpuc->group_flag &= ~PERF_EVENT_TXN;
+ __this_cpu_and(cpu_hw_events.group_flag, ~PERF_EVENT_TXN);
/*
* Truncate the collected events.
*/
- cpuc->n_added -= cpuc->n_txn;
- cpuc->n_events -= cpuc->n_txn;
+ __this_cpu_sub(cpu_hw_events.n_added, __this_cpu_read(cpu_hw_events.n_txn));
+ __this_cpu_sub(cpu_hw_events.n_events, __this_cpu_read(cpu_hw_events.n_txn));
perf_pmu_enable(pmu);
}

diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index c8f5c08..4ee59bc 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -649,7 +649,7 @@ static void intel_pmu_enable_event(struct perf_event *event)
struct hw_perf_event *hwc = &event->hw;

if (unlikely(hwc->idx == X86_PMC_IDX_FIXED_BTS)) {
- if (!__get_cpu_var(cpu_hw_events).enabled)
+ if (!__this_cpu_read(cpu_hw_events.enabled))
return;

intel_pmu_enable_bts(hwc->config);
@@ -679,7 +679,7 @@ static int intel_pmu_save_and_restart(struct perf_event *event)

static void intel_pmu_reset(void)
{
- struct debug_store *ds = __get_cpu_var(cpu_hw_events).ds;
+ struct debug_store *ds = __this_cpu_read(cpu_hw_events.ds);
unsigned long flags;
int idx;

diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 3afb33f..b45246f 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -167,9 +167,9 @@ static void ftrace_mod_code(void)

void ftrace_nmi_enter(void)
{
- __get_cpu_var(save_modifying_code) = modifying_code;
+ __this_cpu_write(save_modifying_code, modifying_code);

- if (!__get_cpu_var(save_modifying_code))
+ if (!__this_cpu_read(save_modifying_code))
return;

if (atomic_inc_return(&nmi_running) & MOD_CODE_WRITE_FLAG) {
@@ -183,7 +183,7 @@ void ftrace_nmi_enter(void)

void ftrace_nmi_exit(void)
{
- if (!__get_cpu_var(save_modifying_code))
+ if (!__this_cpu_read(save_modifying_code))
return;

/* Finish all executions before clearing nmi_running */
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index 42c5942..02f0763 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -122,7 +122,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
return -EBUSY;

set_debugreg(info->address, i);
- __get_cpu_var(cpu_debugreg[i]) = info->address;
+ __this_cpu_write(cpu_debugreg[i], info->address);

dr7 = &__get_cpu_var(cpu_dr7);
*dr7 |= encode_dr7(i, info->len, info->type);
@@ -397,12 +397,12 @@ void flush_ptrace_hw_breakpoint(struct task_struct *tsk)

void hw_breakpoint_restore(void)
{
- set_debugreg(__get_cpu_var(cpu_debugreg[0]), 0);
- set_debugreg(__get_cpu_var(cpu_debugreg[1]), 1);
- set_debugreg(__get_cpu_var(cpu_debugreg[2]), 2);
- set_debugreg(__get_cpu_var(cpu_debugreg[3]), 3);
+ set_debugreg(__this_cpu_read(cpu_debugreg[0]), 0);
+ set_debugreg(__this_cpu_read(cpu_debugreg[1]), 1);
+ set_debugreg(__this_cpu_read(cpu_debugreg[2]), 2);
+ set_debugreg(__this_cpu_read(cpu_debugreg[3]), 3);
set_debugreg(current->thread.debugreg6, 6);
- set_debugreg(__get_cpu_var(cpu_dr7), 7);
+ set_debugreg(__this_cpu_read(cpu_dr7), 7);
}
EXPORT_SYMBOL_GPL(hw_breakpoint_restore);

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 83ec017..3a43caa 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -234,7 +234,7 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
exit_idle();
irq_enter();

- irq = __get_cpu_var(vector_irq)[vector];
+ irq = __this_cpu_read(vector_irq[vector]);

if (!handle_irq(irq, regs)) {
ack_APIC_irq();
@@ -350,12 +350,12 @@ void fixup_irqs(void)
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
unsigned int irr;

- if (__get_cpu_var(vector_irq)[vector] < 0)
+ if (__this_cpu_read(vector_irq[vector]) < 0)
continue;

irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
if (irr & (1 << (vector % 32))) {
- irq = __get_cpu_var(vector_irq)[vector];
+ irq = __this_cpu_read(vector_irq[vector]);

data = irq_get_irq_data(irq);
raw_spin_lock(&desc->lock);
diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 96656f2..48ff6dc 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -79,7 +79,7 @@ execute_on_irq_stack(int overflow, struct irq_desc *desc, int irq)
u32 *isp, arg1, arg2;

curctx = (union irq_ctx *) current_thread_info();
- irqctx = __get_cpu_var(hardirq_ctx);
+ irqctx = __this_cpu_read(hardirq_ctx);

/*
* this is where we switch to the IRQ stack. However, if we are
@@ -166,7 +166,7 @@ asmlinkage void do_softirq(void)

if (local_softirq_pending()) {
curctx = current_thread_info();
- irqctx = __get_cpu_var(softirq_ctx);
+ irqctx = __this_cpu_read(softirq_ctx);
irqctx->tinfo.task = curctx->task;
irqctx->tinfo.previous_esp = current_stack_pointer;

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 083e99d..ff4e5a1 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1377,7 +1377,7 @@ void play_dead_common(void)

mb();
/* Ack it */
- __get_cpu_var(cpu_state) = CPU_DEAD;
+ __this_cpu_write(cpu_state, CPU_DEAD);

/*
* With physical CPU hotplug, we should halt the cpu
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 0c40d8b..acb08dd 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -659,7 +659,7 @@ void restore_sched_clock_state(void)

local_irq_save(flags);

- __get_cpu_var(cyc2ns_offset) = 0;
+ __this_cpu_write(cyc2ns_offset, 0);
offset = cyc2ns_suspend - sched_clock();

for_each_possible_cpu(cpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cdac9e5..79d9606 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -981,7 +981,7 @@ static inline u64 nsec_to_cycles(u64 nsec)
if (kvm_tsc_changes_freq())
printk_once(KERN_WARNING
"kvm: unreliable cycle conversion on adjustable rate TSC\n");
- ret = nsec * __get_cpu_var(cpu_tsc_khz);
+ ret = nsec * __this_cpu_read(cpu_tsc_khz);
do_div(ret, USEC_PER_SEC);
return ret;
}
@@ -1066,7 +1066,7 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
local_irq_save(flags);
kvm_get_msr(v, MSR_IA32_TSC, &tsc_timestamp);
kernel_ns = get_kernel_ns();
- this_tsc_khz = __get_cpu_var(cpu_tsc_khz);
+ this_tsc_khz = __this_cpu_read(cpu_tsc_khz);

if (unlikely(this_tsc_khz == 0)) {
local_irq_restore(flags);
@@ -4432,7 +4432,7 @@ EXPORT_SYMBOL_GPL(kvm_fast_pio_out);

static void tsc_bad(void *info)
{
- __get_cpu_var(cpu_tsc_khz) = 0;
+ __this_cpu_write(cpu_tsc_khz, 0);
}

static void tsc_khz_changed(void *data)
@@ -4446,7 +4446,7 @@ static void tsc_khz_changed(void *data)
khz = cpufreq_quick_get(raw_smp_processor_id());
if (!khz)
khz = tsc_khz;
- __get_cpu_var(cpu_tsc_khz) = khz;
+ __this_cpu_write(cpu_tsc_khz, khz);
}

static int kvmclock_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 4e8baad..a0cae67 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -143,7 +143,7 @@ static inline int has_mux(void)

inline int op_x86_phys_to_virt(int phys)
{
- return __get_cpu_var(switch_index) + phys;
+ return __this_cpu_read(switch_index) + phys;
}

inline int op_x86_virt_to_phys(int virt)
--
1.7.1

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