Description of problem: bug in kscand source code (I think)
active_anon_count used where active_cache_count should be used. See below.


Version-Release number of selected component (if applicable):2.4.21-40


How reproducible:
int kscand(void *unused)
{
        struct task_struct *tsk = current;
        struct zone_struct * zone;
        unsigned long iv;
        int age;

        daemonize();
        strcpy(tsk->comm, "kscand");
        sigfillset(&tsk->blocked);

        for (;;) {
                set_current_state(TASK_INTERRUPTIBLE);
                schedule_timeout(MIN_AGING_INTERVAL);
                for_each_zone(zone) {
                        if (time_before(jiffies, zone->age_next))
                                continue;

                        if (need_active_anon_scan(zone)) {
                                for (age = MAX_AGE-1; age >= 0; age--)  {
                                        scan_active_list(zone, age,
                                                &zone->active_anon_list[age],
                                                zone->active_anon_count[age]);
                                        if (current->need_resched)
                                                schedule();
                                }
                        }

                        if (need_active_cache_scan(zone)) {
                                for (age = MAX_AGE-1; age >= 0; age--)  {
                                        scan_active_list(zone, age,
                                                &zone->active_cache_list[age],
SHOULDN'T THIS BE zone->active_cache_count[age]???
                                                zone->active_anon_count[age]);
                                        if (current->need_resched)
                                                schedule();
                                }
                        }

                        iv = zone->age_interval;
                        /* Check if we've been aging quickly enough ... */
                        if (zone->need_scan >= 2)
                                iv = max(iv / 2, MIN_AGING_INTERVAL);
                        /* ... or too quickly. */
                        else if (!zone->need_scan)
                                iv = min(iv + (iv / 2), MAX_AGING_INTERVAL);
                        zone->need_scan = 0;
                        zone->age_interval = iv;
                        zone->age_next = jiffies + iv;
                }
        }
}