[PATCH 3/3] sched/swait: Rename to exclusive

From: Peter Zijlstra
Date: Tue Jun 12 2018 - 04:39:50 EST

Since swait basically implemented exclusive waits only, make sure
the API reflects that.

$ git grep -l -e "\<swake_up\>"
-e "\<swait_event[^ (]*"
-e "\<prepare_to_swait\>" | while read file;
do
sed -i -e 's/\<swake_up\>/&_one/g'
-e 's/\<swait_event[^ (]*/&_exclusive/g'
-e 's/\<prepare_to_swait\>/&_exclusive/g' $file;
done

With a few manual touch-ups.

Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/mips/kvm/mips.c | 4 ++--
arch/powerpc/kvm/book3s_hv.c | 6 +++---
arch/s390/kvm/interrupt.c | 2 +-
arch/x86/kernel/kvm.c | 4 ++--
arch/x86/kvm/lapic.c | 2 +-
include/linux/swait.h | 24 ++++++++++++------------
kernel/power/suspend.c | 4 ++--
kernel/rcu/srcutiny.c | 4 ++--
kernel/rcu/tree.c | 8 ++++----
kernel/rcu/tree_exp.h | 4 ++--
kernel/rcu/tree_plugin.h | 12 ++++++------
kernel/sched/swait.c | 10 +++++-----
virt/kvm/arm/arm.c | 4 ++--
virt/kvm/arm/psci.c | 2 +-
virt/kvm/async_pf.c | 2 +-
virt/kvm/kvm_main.c | 4 ++--
16 files changed, 48 insertions(+), 48 deletions(-)

--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -515,7 +515,7 @@ int kvm_vcpu_ioctl_interrupt(struct kvm_
dvcpu->arch.wait = 0;

if (swq_has_sleeper(&dvcpu->wq))
- swake_up(&dvcpu->wq);
+ swake_up_one(&dvcpu->wq);

return 0;
}
@@ -1204,7 +1204,7 @@ static void kvm_mips_comparecount_func(u

vcpu->arch.wait = 0;
if (swq_has_sleeper(&vcpu->wq))
- swake_up(&vcpu->wq);
+ swake_up_one(&vcpu->wq);
}

/* low level hrtimer wake routine */
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -190,7 +190,7 @@ static void kvmppc_fast_vcpu_kick_hv(str

wqp = kvm_arch_vcpu_wq(vcpu);
if (swq_has_sleeper(wqp)) {
- swake_up(wqp);
+ swake_up_one(wqp);
++vcpu->stat.halt_wakeup;
}

@@ -3106,7 +3106,7 @@ static void kvmppc_vcore_blocked(struct
}
}

- prepare_to_swait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+ prepare_to_swait_exclusive(&vc->wq, &wait, TASK_INTERRUPTIBLE);

if (kvmppc_vcore_check_block(vc)) {
finish_swait(&vc->wq, &wait);
@@ -3229,7 +3229,7 @@ static int kvmppc_run_vcpu(struct kvm_ru
kvmppc_start_thread(vcpu, vc);
trace_kvm_guest_enter(vcpu);
} else if (vc->vcore_state == VCORE_SLEEPING) {
- swake_up(&vc->wq);
+ swake_up_one(&vc->wq);
}

}
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -1145,7 +1145,7 @@ void kvm_s390_vcpu_wakeup(struct kvm_vcp
* yield-candidate.
*/
vcpu->preempted = true;
- swake_up(&vcpu->wq);
+ swake_up_one(&vcpu->wq);
vcpu->stat.halt_wakeup++;
}
/*
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -154,7 +154,7 @@ void kvm_async_pf_task_wait(u32 token, i

for (;;) {
if (!n.halted)
- prepare_to_swait(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
+ prepare_to_swait_exclusive(&n.wq, &wait, TASK_UNINTERRUPTIBLE);
if (hlist_unhashed(&n.link))
break;

@@ -188,7 +188,7 @@ static void apf_task_wake_one(struct kvm
if (n->halted)
smp_send_reschedule(n->cpu);
else if (swq_has_sleeper(&n->wq))
- swake_up(&n->wq);
+ swake_up_one(&n->wq);
}

static void apf_task_wake_all(void)
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1379,7 +1379,7 @@ static void apic_timer_expired(struct kv
* using swait_active() is safe.
*/
if (swait_active(q))
- swake_up(q);
+ swake_up_one(q);

if (apic_lvtt_tscdeadline(apic))
ktimer->expired_tscdeadline = ktimer->tscdeadline;
--- a/include/linux/swait.h
+++ b/include/linux/swait.h
@@ -16,7 +16,7 @@
* wait-queues, but the semantics are actually completely different, and
* every single user we have ever had has been buggy (or pointless).
*
- * A "swake_up()" only wakes up _one_ waiter, which is not at all what
+ * A "swake_up_one()" only wakes up _one_ waiter, which is not at all what
* "wake_up()" does, and has led to problems. In other cases, it has
* been fine, because there's only ever one waiter (kvm), but in that
* case gthe whole "simple" wait-queue is just pointless to begin with,
@@ -115,7 +115,7 @@ extern void __init_swait_queue_head(stru
* CPU0 - waker CPU1 - waiter
*
* for (;;) {
- * @cond = true; prepare_to_swait(&wq_head, &wait, state);
+ * @cond = true; prepare_to_swait_exclusive(&wq_head, &wait, state);
* smp_mb(); // smp_mb() from set_current_state()
* if (swait_active(wq_head)) if (@cond)
* wake_up(wq_head); break;
@@ -157,11 +157,11 @@ static inline bool swq_has_sleeper(struc
return swait_active(wq);
}

-extern void swake_up(struct swait_queue_head *q);
+extern void swake_up_one(struct swait_queue_head *q);
extern void swake_up_all(struct swait_queue_head *q);
extern void swake_up_locked(struct swait_queue_head *q);

-extern void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state);
+extern void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state);
extern long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state);

extern void __finish_swait(struct swait_queue_head *q, struct swait_queue *wait);
@@ -196,7 +196,7 @@ __out: __ret; \
(void)___swait_event(wq, condition, TASK_UNINTERRUPTIBLE, 0, \
schedule())

-#define swait_event(wq, condition) \
+#define swait_event_exclusive(wq, condition) \
do { \
if (condition) \
break; \
@@ -208,7 +208,7 @@ do { \
TASK_UNINTERRUPTIBLE, timeout, \
__ret = schedule_timeout(__ret))

-#define swait_event_timeout(wq, condition, timeout) \
+#define swait_event_timeout_exclusive(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
@@ -220,7 +220,7 @@ do { \
___swait_event(wq, condition, TASK_INTERRUPTIBLE, 0, \
schedule())

-#define swait_event_interruptible(wq, condition) \
+#define swait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
if (!(condition)) \
@@ -233,7 +233,7 @@ do { \
TASK_INTERRUPTIBLE, timeout, \
__ret = schedule_timeout(__ret))

-#define swait_event_interruptible_timeout(wq, condition, timeout) \
+#define swait_event_interruptible_timeout_exclusive(wq, condition, timeout)\
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
@@ -246,7 +246,7 @@ do { \
(void)___swait_event(wq, condition, TASK_IDLE, 0, schedule())

/**
- * swait_event_idle - wait without system load contribution
+ * swait_event_idle_exclusive - wait without system load contribution
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
*
@@ -257,7 +257,7 @@ do { \
* condition and doesn't want to contribute to system load. Signals are
* ignored.
*/
-#define swait_event_idle(wq, condition) \
+#define swait_event_idle_exclusive(wq, condition) \
do { \
if (condition) \
break; \
@@ -270,7 +270,7 @@ do { \
__ret = schedule_timeout(__ret))

/**
- * swait_event_idle_timeout - wait up to timeout without load contribution
+ * swait_event_idle_timeout_exclusive - wait up to timeout without load contribution
* @wq: the waitqueue to wait on
* @condition: a C expression for the event to wait for
* @timeout: timeout at which we'll give up in jiffies
@@ -288,7 +288,7 @@ do { \
* or the remaining jiffies (at least 1) if the @condition evaluated
* to %true before the @timeout elapsed.
*/
-#define swait_event_idle_timeout(wq, condition, timeout) \
+#define swait_event_idle_timeout_exclusive(wq, condition, timeout) \
({ \
long __ret = timeout; \
if (!___wait_cond_timeout(condition)) \
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -92,7 +92,7 @@ static void s2idle_enter(void)
/* Push all the CPUs into the idle loop. */
wake_up_all_idle_cpus();
/* Make the current CPU wait so it can enter the idle loop too. */
- swait_event(s2idle_wait_head,
+ swait_event_exclusive(s2idle_wait_head,
s2idle_state == S2IDLE_STATE_WAKE);

cpuidle_pause();
@@ -160,7 +160,7 @@ void s2idle_wake(void)
raw_spin_lock_irqsave(&s2idle_lock, flags);
if (s2idle_state > S2IDLE_STATE_NONE) {
s2idle_state = S2IDLE_STATE_WAKE;
- swake_up(&s2idle_wait_head);
+ swake_up_one(&s2idle_wait_head);
}
raw_spin_unlock_irqrestore(&s2idle_lock, flags);
}
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -110,7 +110,7 @@ void __srcu_read_unlock(struct srcu_stru

WRITE_ONCE(sp->srcu_lock_nesting[idx], newval);
if (!newval && READ_ONCE(sp->srcu_gp_waiting))
- swake_up(&sp->srcu_wq);
+ swake_up_one(&sp->srcu_wq);
}
EXPORT_SYMBOL_GPL(__srcu_read_unlock);

@@ -140,7 +140,7 @@ void srcu_drive_gp(struct work_struct *w
idx = sp->srcu_idx;
WRITE_ONCE(sp->srcu_idx, !sp->srcu_idx);
WRITE_ONCE(sp->srcu_gp_waiting, true); /* srcu_read_unlock() wakes! */
- swait_event(sp->srcu_wq, !READ_ONCE(sp->srcu_lock_nesting[idx]));
+ swait_event_exclusive(sp->srcu_wq, !READ_ONCE(sp->srcu_lock_nesting[idx]));
WRITE_ONCE(sp->srcu_gp_waiting, false); /* srcu_read_unlock() cheap. */

/* Invoke the callbacks we removed above. */
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1727,7 +1727,7 @@ static void rcu_gp_kthread_wake(struct r
!READ_ONCE(rsp->gp_flags) ||
!rsp->gp_kthread)
return;
- swake_up(&rsp->gp_wq);
+ swake_up_one(&rsp->gp_wq);
}

/*
@@ -2002,7 +2002,7 @@ static bool rcu_gp_init(struct rcu_state
}

/*
- * Helper function for swait_event_idle() wakeup at force-quiescent-state
+ * Helper function for swait_event_idle_exclusive() wakeup at force-quiescent-state
* time.
*/
static bool rcu_gp_fqs_check_wake(struct rcu_state *rsp, int *gfp)
@@ -2144,7 +2144,7 @@ static int __noreturn rcu_gp_kthread(voi
READ_ONCE(rsp->gpnum),
TPS("reqwait"));
rsp->gp_state = RCU_GP_WAIT_GPS;
- swait_event_idle(rsp->gp_wq, READ_ONCE(rsp->gp_flags) &
+ swait_event_idle_exclusive(rsp->gp_wq, READ_ONCE(rsp->gp_flags) &
RCU_GP_FLAG_INIT);
rsp->gp_state = RCU_GP_DONE_GPS;
/* Locking provides needed memory barrier. */
@@ -2176,7 +2176,7 @@ static int __noreturn rcu_gp_kthread(voi
READ_ONCE(rsp->gpnum),
TPS("fqswait"));
rsp->gp_state = RCU_GP_WAIT_FQS;
- ret = swait_event_idle_timeout(rsp->gp_wq,
+ ret = swait_event_idle_timeout_exclusive(rsp->gp_wq,
rcu_gp_fqs_check_wake(rsp, &gf), j);
rsp->gp_state = RCU_GP_DOING_FQS;
/* Locking provides needed memory barriers. */
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -212,7 +212,7 @@ static void __rcu_report_exp_rnp(struct
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
if (wake) {
smp_mb(); /* EGP done before wake_up(). */
- swake_up(&rsp->expedited_wq);
+ swake_up_one(&rsp->expedited_wq);
}
break;
}
@@ -518,7 +518,7 @@ static void synchronize_sched_expedited_
jiffies_start = jiffies;

for (;;) {
- ret = swait_event_timeout(
+ ret = swait_event_timeout_exclusive(
rsp->expedited_wq,
sync_rcu_preempt_exp_done_unlocked(rnp_root),
jiffies_stall);
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1854,8 +1854,8 @@ static void __wake_nocb_leader(struct rc
WRITE_ONCE(rdp_leader->nocb_leader_sleep, false);
del_timer(&rdp->nocb_timer);
raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags);
- smp_mb(); /* ->nocb_leader_sleep before swake_up(). */
- swake_up(&rdp_leader->nocb_wq);
+ smp_mb(); /* ->nocb_leader_sleep before swake_up_one(). */
+ swake_up_one(&rdp_leader->nocb_wq);
} else {
raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags);
}
@@ -2082,7 +2082,7 @@ static void rcu_nocb_wait_gp(struct rcu_
*/
trace_rcu_this_gp(rnp, rdp, c, TPS("StartWait"));
for (;;) {
- swait_event_interruptible(
+ swait_event_interruptible_exclusive(
rnp->nocb_gp_wq[c & 0x1],
(d = ULONG_CMP_GE(READ_ONCE(rnp->completed), c)));
if (likely(d))
@@ -2111,7 +2111,7 @@ static void nocb_leader_wait(struct rcu_
/* Wait for callbacks to appear. */
if (!rcu_nocb_poll) {
trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, TPS("Sleep"));
- swait_event_interruptible(my_rdp->nocb_wq,
+ swait_event_interruptible_exclusive(my_rdp->nocb_wq,
!READ_ONCE(my_rdp->nocb_leader_sleep));
raw_spin_lock_irqsave(&my_rdp->nocb_lock, flags);
my_rdp->nocb_leader_sleep = true;
@@ -2176,7 +2176,7 @@ static void nocb_leader_wait(struct rcu_
raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags);
if (rdp != my_rdp && tail == &rdp->nocb_follower_head) {
/* List was empty, so wake up the follower. */
- swake_up(&rdp->nocb_wq);
+ swake_up_one(&rdp->nocb_wq);
}
}

@@ -2193,7 +2193,7 @@ static void nocb_follower_wait(struct rc
{
for (;;) {
trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, TPS("FollowerSleep"));
- swait_event_interruptible(rdp->nocb_wq,
+ swait_event_interruptible_exclusive(rdp->nocb_wq,
READ_ONCE(rdp->nocb_follower_head));
if (smp_load_acquire(&rdp->nocb_follower_head)) {
/* ^^^ Ensure CB invocation follows _head test. */
--- a/kernel/sched/swait.c
+++ b/kernel/sched/swait.c
@@ -32,7 +32,7 @@ void swake_up_locked(struct swait_queue_
}
EXPORT_SYMBOL(swake_up_locked);

-void swake_up(struct swait_queue_head *q)
+void swake_up_one(struct swait_queue_head *q)
{
unsigned long flags;

@@ -40,7 +40,7 @@ void swake_up(struct swait_queue_head *q
swake_up_locked(q);
raw_spin_unlock_irqrestore(&q->lock, flags);
}
-EXPORT_SYMBOL(swake_up);
+EXPORT_SYMBOL(swake_up_one);

/*
* Does not allow usage from IRQ disabled, since we must be able to
@@ -76,7 +76,7 @@ static void __prepare_to_swait(struct sw
list_add_tail(&wait->task_list, &q->task_list);
}

-void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state)
+void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *wait, int state)
{
unsigned long flags;

@@ -85,7 +85,7 @@ void prepare_to_swait(struct swait_queue
set_current_state(state);
raw_spin_unlock_irqrestore(&q->lock, flags);
}
-EXPORT_SYMBOL(prepare_to_swait);
+EXPORT_SYMBOL(prepare_to_swait_exclusive);

long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait, int state)
{
@@ -95,7 +95,7 @@ long prepare_to_swait_event(struct swait
raw_spin_lock_irqsave(&q->lock, flags);
if (unlikely(signal_pending_state(state, current))) {
/*
- * See prepare_to_wait_event(). TL;DR, subsequent swake_up()
+ * See prepare_to_wait_event(). TL;DR, subsequent swake_up_one()
* must not see us.
*/
list_del_init(&wait->task_list);
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -586,7 +586,7 @@ void kvm_arm_resume_guest(struct kvm *kv

kvm_for_each_vcpu(i, vcpu, kvm) {
vcpu->arch.pause = false;
- swake_up(kvm_arch_vcpu_wq(vcpu));
+ swake_up_one(kvm_arch_vcpu_wq(vcpu));
}
}

@@ -594,7 +594,7 @@ static void vcpu_req_sleep(struct kvm_vc
{
struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);

- swait_event_interruptible(*wq, ((!vcpu->arch.power_off) &&
+ swait_event_interruptible_exclusive(*wq, ((!vcpu->arch.power_off) &&
(!vcpu->arch.pause)));

if (vcpu->arch.power_off || vcpu->arch.pause) {
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -155,7 +155,7 @@ static unsigned long kvm_psci_vcpu_on(st
smp_mb(); /* Make sure the above is visible */

wq = kvm_arch_vcpu_wq(vcpu);
- swake_up(wq);
+ swake_up_one(wq);

return PSCI_RET_SUCCESS;
}
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -107,7 +107,7 @@ static void async_pf_execute(struct work
trace_kvm_async_pf_completed(addr, gva);

if (swq_has_sleeper(&vcpu->wq))
- swake_up(&vcpu->wq);
+ swake_up_one(&vcpu->wq);

mmput(mm);
kvm_put_kvm(vcpu->kvm);
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2155,7 +2155,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcp
kvm_arch_vcpu_blocking(vcpu);

for (;;) {
- prepare_to_swait(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);
+ prepare_to_swait_exclusive(&vcpu->wq, &wait, TASK_INTERRUPTIBLE);

if (kvm_vcpu_check_block(vcpu) < 0)
break;
@@ -2197,7 +2197,7 @@ bool kvm_vcpu_wake_up(struct kvm_vcpu *v

wqp = kvm_arch_vcpu_wq(vcpu);
if (swq_has_sleeper(wqp)) {
- swake_up(wqp);
+ swake_up_one(wqp);
++vcpu->stat.halt_wakeup;
return true;
}