# HG changeset patch
# User Keir Fraser <keir@xxxxxxx>
# Date 1289922088 0
# Node ID deb438d43e79943643914f708b37354dc53f79f4
# Parent e1a6a9ab7ef52ac17a873ad99037803640301491
Add locking-depth debugging, introduce in_atomic() boolean.
This will be useful for debugging use of sleep-in-hypervisor
primitives.
Signed-off-by: Keir Fraser <keir@xxxxxxx>
---
xen/common/schedule.c | 2 -
xen/common/softirq.c | 1
xen/common/spinlock.c | 46 +++++++++++++++++++++++++++++++++++++++------
xen/include/xen/lib.h | 2 +
xen/include/xen/spinlock.h | 2 +
5 files changed, 46 insertions(+), 7 deletions(-)
diff -r e1a6a9ab7ef5 -r deb438d43e79 xen/common/schedule.c
--- a/xen/common/schedule.c Tue Nov 16 14:16:36 2010 +0000
+++ b/xen/common/schedule.c Tue Nov 16 15:41:28 2010 +0000
@@ -1047,7 +1047,7 @@ static void schedule(void)
struct schedule_data *sd;
struct task_slice next_slice;
- ASSERT(!in_irq());
+ ASSERT(!in_atomic());
perfc_incr(sched_run);
diff -r e1a6a9ab7ef5 -r deb438d43e79 xen/common/softirq.c
--- a/xen/common/softirq.c Tue Nov 16 14:16:36 2010 +0000
+++ b/xen/common/softirq.c Tue Nov 16 15:41:28 2010 +0000
@@ -57,6 +57,7 @@ void process_pending_softirqs(void)
asmlinkage void do_softirq(void)
{
+ ASSERT(!in_atomic());
__do_softirq(0);
}
diff -r e1a6a9ab7ef5 -r deb438d43e79 xen/common/spinlock.c
--- a/xen/common/spinlock.c Tue Nov 16 14:16:36 2010 +0000
+++ b/xen/common/spinlock.c Tue Nov 16 15:41:28 2010 +0000
@@ -39,9 +39,22 @@ void spin_debug_disable(void)
atomic_dec(&spin_debug);
}
+static DEFINE_PER_CPU(atomic_t, lockdepth);
+
+#define lockdepth_inc() atomic_inc(&this_cpu(lockdepth))
+#define lockdepth_dec() atomic_dec(&this_cpu(lockdepth))
+
+unsigned int locking_depth(void)
+{
+ return atomic_read(&this_cpu(lockdepth));
+}
+
#else /* defined(NDEBUG) */
#define check_lock(l) ((void)0)
+#define lockdepth_inc() ((void)0)
+#define lockdepth_dec() ((void)0)
+unsigned int locking_depth(void) { return 0; }
#endif
@@ -81,6 +94,7 @@ void _spin_lock(spinlock_t *lock)
cpu_relax();
}
LOCK_PROFILE_GOT;
+ lockdepth_inc();
}
void _spin_lock_irq(spinlock_t *lock)
@@ -99,6 +113,7 @@ void _spin_lock_irq(spinlock_t *lock)
local_irq_disable();
}
LOCK_PROFILE_GOT;
+ lockdepth_inc();
}
unsigned long _spin_lock_irqsave(spinlock_t *lock)
@@ -117,17 +132,20 @@ unsigned long _spin_lock_irqsave(spinloc
local_irq_save(flags);
}
LOCK_PROFILE_GOT;
+ lockdepth_inc();
return flags;
}
void _spin_unlock(spinlock_t *lock)
{
+ lockdepth_dec();
LOCK_PROFILE_REL;
_raw_spin_unlock(&lock->raw);
}
void _spin_unlock_irq(spinlock_t *lock)
{
+ lockdepth_dec();
LOCK_PROFILE_REL;
_raw_spin_unlock(&lock->raw);
local_irq_enable();
@@ -135,6 +153,7 @@ void _spin_unlock_irq(spinlock_t *lock)
void _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
+ lockdepth_dec();
LOCK_PROFILE_REL;
_raw_spin_unlock(&lock->raw);
local_irq_restore(flags);
@@ -149,13 +168,13 @@ int _spin_trylock(spinlock_t *lock)
int _spin_trylock(spinlock_t *lock)
{
check_lock(&lock->debug);
-#ifndef LOCK_PROFILE
- return _raw_spin_trylock(&lock->raw);
-#else
- if (!_raw_spin_trylock(&lock->raw)) return 0;
+ if ( !_raw_spin_trylock(&lock->raw) )
+ return 0;
+#ifdef LOCK_PROFILE
lock->profile.time_locked = NOW();
+#endif
+ lockdepth_inc();
return 1;
-#endif
}
void _spin_barrier(spinlock_t *lock)
@@ -228,6 +247,7 @@ void _read_lock(rwlock_t *lock)
{
check_lock(&lock->debug);
_raw_read_lock(&lock->raw);
+ lockdepth_inc();
}
void _read_lock_irq(rwlock_t *lock)
@@ -236,6 +256,7 @@ void _read_lock_irq(rwlock_t *lock)
local_irq_disable();
check_lock(&lock->debug);
_raw_read_lock(&lock->raw);
+ lockdepth_inc();
}
unsigned long _read_lock_irqsave(rwlock_t *lock)
@@ -244,22 +265,26 @@ unsigned long _read_lock_irqsave(rwlock_
local_irq_save(flags);
check_lock(&lock->debug);
_raw_read_lock(&lock->raw);
+ lockdepth_inc();
return flags;
}
void _read_unlock(rwlock_t *lock)
{
+ lockdepth_dec();
_raw_read_unlock(&lock->raw);
}
void _read_unlock_irq(rwlock_t *lock)
{
+ lockdepth_dec();
_raw_read_unlock(&lock->raw);
local_irq_enable();
}
void _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
+ lockdepth_dec();
_raw_read_unlock(&lock->raw);
local_irq_restore(flags);
}
@@ -268,6 +293,7 @@ void _write_lock(rwlock_t *lock)
{
check_lock(&lock->debug);
_raw_write_lock(&lock->raw);
+ lockdepth_inc();
}
void _write_lock_irq(rwlock_t *lock)
@@ -276,6 +302,7 @@ void _write_lock_irq(rwlock_t *lock)
local_irq_disable();
check_lock(&lock->debug);
_raw_write_lock(&lock->raw);
+ lockdepth_inc();
}
unsigned long _write_lock_irqsave(rwlock_t *lock)
@@ -284,28 +311,35 @@ unsigned long _write_lock_irqsave(rwlock
local_irq_save(flags);
check_lock(&lock->debug);
_raw_write_lock(&lock->raw);
+ lockdepth_inc();
return flags;
}
int _write_trylock(rwlock_t *lock)
{
check_lock(&lock->debug);
- return _raw_write_trylock(&lock->raw);
+ if ( !_raw_write_trylock(&lock->raw) )
+ return 0;
+ lockdepth_inc();
+ return 1;
}
void _write_unlock(rwlock_t *lock)
{
+ lockdepth_dec();
_raw_write_unlock(&lock->raw);
}
void _write_unlock_irq(rwlock_t *lock)
{
+ lockdepth_dec();
_raw_write_unlock(&lock->raw);
local_irq_enable();
}
void _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
+ lockdepth_dec();
_raw_write_unlock(&lock->raw);
local_irq_restore(flags);
}
diff -r e1a6a9ab7ef5 -r deb438d43e79 xen/include/xen/lib.h
--- a/xen/include/xen/lib.h Tue Nov 16 14:16:36 2010 +0000
+++ b/xen/include/xen/lib.h Tue Nov 16 15:41:28 2010 +0000
@@ -119,4 +119,6 @@ struct cpu_user_regs;
struct cpu_user_regs;
void dump_execstate(struct cpu_user_regs *);
+#define in_atomic() (locking_depth() || in_irq() || !local_irq_is_enabled())
+
#endif /* __LIB_H__ */
diff -r e1a6a9ab7ef5 -r deb438d43e79 xen/include/xen/spinlock.h
--- a/xen/include/xen/spinlock.h Tue Nov 16 14:16:36 2010 +0000
+++ b/xen/include/xen/spinlock.h Tue Nov 16 15:41:28 2010 +0000
@@ -223,4 +223,6 @@ int _rw_is_write_locked(rwlock_t *lock);
#define rw_is_locked(l) _rw_is_locked(l)
#define rw_is_write_locked(l) _rw_is_write_locked(l)
+unsigned int locking_depth(void);
+
#endif /* __SPINLOCK_H__ */
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