From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Completions have no long lasting callbacks and therefor do not need
the complex waitqueue variant. Use simple waitqueues which reduces the
contention on the waitqueue lock.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
drivers/net/wireless/orinoco/orinoco_usb.c | 2 +-
drivers/usb/gadget/function/f_fs.c | 2 +-
drivers/usb/gadget/legacy/inode.c | 4 ++--
include/linux/completion.h | 9 ++++-----
include/linux/uprobes.h | 1 +
kernel/sched/completion.c | 32 +++++++++++++++---------------
kernel/sched/core.c | 10 ++++++++--
7 files changed, 33 insertions(+), 27 deletions(-)
diff --git a/drivers/net/wireless/orinoco/orinoco_usb.c b/drivers/net/wireless/orinoco/orinoco_usb.c
index 91f0544..8fb1c92 100644
--- a/drivers/net/wireless/orinoco/orinoco_usb.c
+++ b/drivers/net/wireless/orinoco/orinoco_usb.c
@@ -697,7 +697,7 @@ static void ezusb_req_ctx_wait(struct ezusb_priv *upriv,
while (!ctx->done.done && msecs--)
udelay(1000);
} else {
- wait_event_interruptible(ctx->done.wait,
+ swait_event_interruptible(ctx->done.wait,
ctx->done.done);
}
break;
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 6e7be91..f51bb89 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1405,7 +1405,7 @@ static void ffs_data_put(struct ffs_data *ffs)
pr_info("%s(): freeing\n", __func__);
ffs_data_clear(ffs);
BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
- waitqueue_active(&ffs->ep0req_completion.wait));
+ swaitqueue_active(&ffs->ep0req_completion.wait));
kfree(ffs->dev_name);
kfree(ffs);
}
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index 2030565..7b6da0f 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -345,7 +345,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
spin_unlock_irq (&epdata->dev->lock);
if (likely (value == 0)) {
- value = wait_event_interruptible (done.wait, done.done);
+ value = swait_event_interruptible (done.wait, done.done);
if (value != 0) {
spin_lock_irq (&epdata->dev->lock);
if (likely (epdata->ep != NULL)) {
@@ -354,7 +354,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
usb_ep_dequeue (epdata->ep, epdata->req);
spin_unlock_irq (&epdata->dev->lock);
- wait_event (done.wait, done.done);
+ swait_event (done.wait, done.done);
if (epdata->status == -ECONNRESET)
epdata->status = -EINTR;
} else {
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 5d5aaae..3bca159 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -7,8 +7,7 @@
* Atomic wait-for-completion handler data structures.
* See kernel/sched/completion.c for details.
*/
-
-#include <linux/wait.h>
+#include <linux/swait.h>
/*
* struct completion - structure used to maintain state for a "completion"
@@ -24,11 +23,11 @@
*/
struct completion {
unsigned int done;
- wait_queue_head_t wait;
+ struct swait_queue_head wait;
};
#define COMPLETION_INITIALIZER(work) \
- { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+ { 0, __SWAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
#define COMPLETION_INITIALIZER_ONSTACK(work) \
({ init_completion(&work); work; })
@@ -73,7 +72,7 @@ struct completion {
static inline void init_completion(struct completion *x)
{
x->done = 0;
- init_waitqueue_head(&x->wait);
+ init_swait_queue_head(&x->wait);
}
/**
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 60beb5d..19769d3 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -27,6 +27,7 @@
#include <linux/errno.h>
#include <linux/rbtree.h>
#include <linux/types.h>
+#include <linux/swait.h>
struct vm_area_struct;
struct mm_struct;
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 8d0f35d..0e2541b 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -30,10 +30,10 @@ void complete(struct completion *x)
{
unsigned long flags;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
x->done++;
- __wake_up_locked(&x->wait, TASK_NORMAL, 1);
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ swake_up_locked(&x->wait);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
}
EXPORT_SYMBOL(complete);
@@ -50,10 +50,10 @@ void complete_all(struct completion *x)
{
unsigned long flags;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
x->done += UINT_MAX/2;
- __wake_up_locked(&x->wait, TASK_NORMAL, 0);
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
+ swake_up_all(&x->wait);
}
EXPORT_SYMBOL(complete_all);
@@ -62,20 +62,20 @@ do_wait_for_common(struct completion *x,
long (*action)(long), long timeout, int state)
{
if (!x->done) {
- DECLARE_WAITQUEUE(wait, current);
+ DECLARE_SWAITQUEUE(wait);
- __add_wait_queue_tail_exclusive(&x->wait, &wait);
+ __prepare_to_swait(&x->wait, &wait);
do {
if (signal_pending_state(state, current)) {
timeout = -ERESTARTSYS;
break;
}
__set_current_state(state);
- spin_unlock_irq(&x->wait.lock);
+ raw_spin_unlock_irq(&x->wait.lock);
timeout = action(timeout);
- spin_lock_irq(&x->wait.lock);
+ raw_spin_lock_irq(&x->wait.lock);
} while (!x->done && timeout);
- __remove_wait_queue(&x->wait, &wait);
+ __finish_swait(&x->wait, &wait);
if (!x->done)
return timeout;
}
@@ -89,9 +89,9 @@ __wait_for_common(struct completion *x,
{
might_sleep();
- spin_lock_irq(&x->wait.lock);
+ raw_spin_lock_irq(&x->wait.lock);
timeout = do_wait_for_common(x, action, timeout, state);
- spin_unlock_irq(&x->wait.lock);
+ raw_spin_unlock_irq(&x->wait.lock);
return timeout;
}
@@ -277,12 +277,12 @@ bool try_wait_for_completion(struct completion *x)
if (!READ_ONCE(x->done))
return 0;
- spin_lock_irqsave(&x->wait.lock, flags);
+ raw_spin_lock_irqsave(&x->wait.lock, flags);
if (!x->done)
ret = 0;
else
x->done--;
- spin_unlock_irqrestore(&x->wait.lock, flags);
+ raw_spin_unlock_irqrestore(&x->wait.lock, flags);
return ret;
}
EXPORT_SYMBOL(try_wait_for_completion);
@@ -311,7 +311,7 @@ bool completion_done(struct completion *x)
* after it's acquired the lock.
*/
smp_rmb();
- spin_unlock_wait(&x->wait.lock);
+ raw_spin_unlock_wait(&x->wait.lock);
return true;
}
EXPORT_SYMBOL(completion_done);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e1a68aa..799b75b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2797,7 +2797,10 @@ void migrate_disable(void)
}
#ifdef CONFIG_SCHED_DEBUG
- WARN_ON_ONCE(p->migrate_disable_atomic);
+ if (unlikely(p->migrate_disable_atomic)) {
+ tracing_off();
+ WARN_ON_ONCE(1);
+ }
#endif
if (p->migrate_disable) {
@@ -2828,7 +2831,10 @@ void migrate_enable(void)
}
#ifdef CONFIG_SCHED_DEBUG
- WARN_ON_ONCE(p->migrate_disable_atomic);
+ if (unlikely(p->migrate_disable_atomic)) {
+ tracing_off();
+ WARN_ON_ONCE(1);
+ }
#endif
WARN_ON_ONCE(p->migrate_disable <= 0);
--
2.4.3
--
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