Hi!
> Don't know who put this in for 2.5.38.
>
> I realize that using xchg() makes you 'leet. But doing an atomic op
> where none is required is suboptimal and confusing.
Well, atomic op is also more expensive. i think ingo did this. Ingo, is
patch below safe? It is faster *and* it works on 386.
Pavel
> diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.38/kernel/fork.c working-2.5.38-unxchg/kernel/fork.c
> --- linux-2.5.38/kernel/fork.c 2002-09-21 13:55:19.000000000 +1000
> +++ working-2.5.38-unxchg/kernel/fork.c 2002-09-23 11:00:31.000000000 +1000
> @@ -64,11 +64,12 @@ void __put_task_struct(struct task_struc
> } else {
> int cpu = smp_processor_id();
>
> - tsk = xchg(task_cache + cpu, tsk);
> + tsk = task_cache[cpu];
> if (tsk) {
> free_thread_info(tsk->thread_info);
> kmem_cache_free(task_struct_cachep,tsk);
> }
> + task_cache[cpu] = current;
> }
> }
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