Hi Håkon,
> +#define BIT_ACCESS_FUNCTIONS(b) \
> + static inline void set_##b(unsigned long flags) \
> + { \
> + /* set_bit() does not imply a memory barrier */ \
> + smp_mb__before_atomic(); \
> + set_bit(b, &flags); \
> + /* set_bit() does not imply a memory barrier */ \
> + smp_mb__after_atomic(); \
> + } \
Don't you need to pass flags by reference to the inline function?
As far as I can see set_bit() operates on a temporary variable.
In order to check if inline functions are special I wrote this little check:
$ cat inline_arg.c
#include <stdio.h>
static inline void func(unsigned s, unsigned *p)
{
printf("&s=%p p=%p\n", &s, p);
}
int main(void)
{
unsigned flags = 0;
func(flags, &flags);
return 0;
}
$ gcc -O0 -o inline_arg inline_arg.c
$ ./inline_arg
&s=0x7ffd3a71616c p=0x7ffd3a716184
$ gcc -O6 -o inline_arg inline_arg.c
$ ./inline_arg
&s=0x7ffd87781064 p=0x7ffd87781060
It means s doesn't magically become 'flags' of the caller...
I'm I missing something?
metze
