Christoph Lameter <[email protected]> wrote:
>
> V1->V2:
> - Allow an arch to provide its on atomic_long_t, so that arches such
> as sh64 can provide their own atomic_long_t.
> - Make sure that atomic_long_read() always returns (long) even if the
> arch uses 32 bit for atomic_long_t so that
> printk("%ld", atomic_long_read(v))
> always works (not sure how this could work right if atomic_long is
> long long like for sh4 but I think that is up to the sh64 developers to
> figure out).
>
> Several counters already have the need to use 64 atomic variables on 64
> bit platforms (see mm_counter_t in sched.h). We have to do ugly ifdefs to
> fall back to 32 bit atomic on 32 bit platforms.
>
> The VM statistics patch that I am working on will also need to make more
> extensive use of atomic64.
>
> This patch introduces a new type atomic_long_t by providing definitions in
> asm-generic/atomic.h that works similar to the c "long" type. Its 32 bits on
> 32 bit platforms and 64 bits on 64 bit platforms.
I dunno, this still looks kludgy. It looks like we couldn't be assed
implementing atomic_long_t in each architecture ;)
How about requiring that all 64-bit archs implement atomic64_t and do:
#if BIT_PER_LONG == 64
typedef atomic64_t atomic_long_t
static inline long atomic_long_read(atomic_long_t *vl)
{
/* typecast the return value in case arch uses long long */
return (long)atomic64_read((atomic64_t *)vl);
}
...
static inline void atomic_long_set(atomic_long_t *vl, long i)
{
/*
* Do the cast separately to avoid possible cast-as-lval errors
*/
atomic64_t *v = (atomic64_t *)vl;
atomic64_set(v, i);
}
#else
typedef atomic_t atomic_long_t
static inline long atomic_long_read(atomic_long_t *vl)
{
return atomic_read((atomic_t *)vl);
}
...
static inline void atomic_long_set(atomic_long_t *vl, long i)
{
atomic_t *v = (atomic_t *)vl;
atomic_set(v, i);
}
#endif
?
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
