preempt_enable();
put_cpu_var(bh_accounting);
struct buffer_head *alloc_buffer_head(unsigned int __nocast gfp_flags){	struct buffer_head *ret = kmem_cache_alloc(bh_cachep, gfp_flags);	if (ret) {		preempt_disable();		__get_cpu_var(bh_accounting).nr++;		recalc_bh_state();		preempt_enable();	}	return ret;}