[PATCH][for -mm] Fix and Enhancements for memory cgroup [1/6] fix refcnt race in charge/uncharge

[KAMEZAWA Hiroyuki]

On Wed, 10 Oct 2007 07:31:38 +0900 (JST)
yamamoto at valinux.co.jp (YAMAMOTO Takashi) wrote:
> > -		atomic_inc(&pc->ref_cnt);
> > -		goto done;
> > +		if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) {
> > +			/* this page is under being uncharge ? */
> > +			unlock_page_cgroup(page);
> 
> cpu_relax() here?
> 
Ah, yes. there should be. I'll add.

Thanks,
-Kame