On Tue 29-03-11 21:40:13, Zhu Yanhai wrote:

Michal,
IIUC it's to prevent the infinite loop, as in the end of the do-while
there's
if (!nr_reclaimed &&
    (next_mz == NULL ||
    loop > MEM_CGROUP_MAX_SOFT_LIMIT_RECLAIM_LOOPS))
		break;

so the loop will break earlier if all groups are iterated once and no
pages are freed.

The code (in mmotm 2011-03-10-16-42) reads:
			do {
				[skipped comments]
                                next_mz =
                                __mem_cgroup_largest_soft_limit_node(mctz);
                                if (next_mz == mz) {
                                        css_put(&next_mz->mem->css);
					next_mz = NULL;
                                } else /* next_mz == NULL or other memcg */
                                        break;
                        } while (1);

So we do not break out of the loop and start a new iteration if next_mz == mz
and assign next_mz again.
Am I missing something?
-- 
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9    
Czech Republic

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>