On Tue, Apr 15, 2003 at 01:57:32PM +0200, Duncan Sands wrote:
> It is questionable. Since even in core kernel code there are
> many places with
> if (cond)
> BUG();
> rather than
> BUG_ON(cond);
> it may be worth seeing if converting them makes a difference
> (increases code size though).
The spinlock code sticks out as a possible good target.
Any takers for benchmarking ?
Dave
diff -urpN --exclude-from=/home/davej/.exclude bk-linus/include/asm-i386/mmu_context.h linux-2.5/include/asm-i386/mmu_context.h
--- bk-linus/include/asm-i386/mmu_context.h 2003-04-10 06:01:31.000000000 +0100
+++ linux-2.5/include/asm-i386/mmu_context.h 2003-04-15 06:02:46.000000000 +0100
@@ -45,8 +45,8 @@ static inline void switch_mm(struct mm_s
#ifdef CONFIG_SMP
else {
cpu_tlbstate[cpu].state = TLBSTATE_OK;
- if (cpu_tlbstate[cpu].active_mm != next)
- BUG();
+ BUG_ON (cpu_tlbstate[cpu].active_mm != next);
+
if (!test_and_set_bit(cpu, &next->cpu_vm_mask)) {
/* We were in lazy tlb mode and leave_mm disabled
* tlb flush IPI delivery. We must reload %cr3.
diff -urpN --exclude-from=/home/davej/.exclude bk-linus/include/asm-i386/spinlock.h linux-2.5/include/asm-i386/spinlock.h
--- bk-linus/include/asm-i386/spinlock.h 2003-04-10 06:01:31.000000000 +0100
+++ linux-2.5/include/asm-i386/spinlock.h 2003-04-15 06:02:46.000000000 +0100
@@ -5,6 +5,7 @@
#include <asm/rwlock.h>
#include <asm/page.h>
#include <linux/config.h>
+#include <linux/compiler.h>
extern int printk(const char * fmt, ...)
__attribute__ ((format (printf, 1, 2)));
@@ -70,10 +71,8 @@ typedef struct {
static inline void _raw_spin_unlock(spinlock_t *lock)
{
#ifdef CONFIG_DEBUG_SPINLOCK
- if (lock->magic != SPINLOCK_MAGIC)
- BUG();
- if (!spin_is_locked(lock))
- BUG();
+ BUG_ON (lock->magic != SPINLOCK_MAGIC);
+ BUG_ON (!spin_is_locked(lock));
#endif
__asm__ __volatile__(
spin_unlock_string
@@ -91,10 +90,8 @@ static inline void _raw_spin_unlock(spin
{
char oldval = 1;
#ifdef CONFIG_DEBUG_SPINLOCK
- if (lock->magic != SPINLOCK_MAGIC)
- BUG();
- if (!spin_is_locked(lock))
- BUG();
+ BUG_ON (lock->magic != SPINLOCK_MAGIC);
+ BUG_ON (!spin_is_locked(lock));
#endif
__asm__ __volatile__(
spin_unlock_string
@@ -118,8 +115,8 @@ static inline void _raw_spin_lock(spinlo
#ifdef CONFIG_DEBUG_SPINLOCK
__label__ here;
here:
- if (lock->magic != SPINLOCK_MAGIC) {
-printk("eip: %p\n", &&here);
+ if (unlikely(lock->magic != SPINLOCK_MAGIC)) {
+ printk("eip: %p\n", &&here);
BUG();
}
#endif
@@ -174,8 +171,7 @@ typedef struct {
static inline void _raw_read_lock(rwlock_t *rw)
{
#ifdef CONFIG_DEBUG_SPINLOCK
- if (rw->magic != RWLOCK_MAGIC)
- BUG();
+ BUG_ON (rw->magic != RWLOCK_MAGIC);
#endif
__build_read_lock(rw, "__read_lock_failed");
}
@@ -183,8 +179,7 @@ static inline void _raw_read_lock(rwlock
static inline void _raw_write_lock(rwlock_t *rw)
{
#ifdef CONFIG_DEBUG_SPINLOCK
- if (rw->magic != RWLOCK_MAGIC)
- BUG();
+ BUG_ON (rw->magic != RWLOCK_MAGIC);
#endif
__build_write_lock(rw, "__write_lock_failed");
}
-
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This archive was generated by hypermail 2b29 : Tue Apr 15 2003 - 22:00:35 EST