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    SubjectRe: Kernel falls apart under light memory pressure (i.e. linking vmlinux)
    > diff --git a/mm/vmscan.c b/mm/vmscan.c
    > index 3f44b81..d1dabc9 100644
    > @@ -1426,8 +1437,13 @@ shrink_inactive_list(unsigned long nr_to_scan,
    > struct zone *zone,
    >
    >        /* Check if we should syncronously wait for writeback */
    >        if (should_reclaim_stall(nr_taken, nr_reclaimed, priority, sc)) {
    > +               unsigned long nr_active, old_nr_scanned;
    >                set_reclaim_mode(priority, sc, true);
    > +               nr_active = clear_active_flags(&page_list, NULL);
    > +               count_vm_events(PGDEACTIVATE, nr_active);
    > +               old_nr_scanned = sc->nr_scanned;
    >                nr_reclaimed += shrink_page_list(&page_list, zone, sc);
    > +               sc->nr_scanned = old_nr_scanned;
    >        }
    >
    >        local_irq_disable();
    >
    > I just tested 2.6.38.6 with the attached patch.  It survived dirty_ram
    > and test_mempressure without any problems other than slowness, but
    > when I hit ctrl-c to stop test_mempressure, I got the attached oom.

    Minchan,

    I'm confused now.
    If pages got SetPageActive(), should_reclaim_stall() should never return true.
    Can you please explain which bad scenario was happen?

    -----------------------------------------------------------------------------------------------------
    static void reset_reclaim_mode(struct scan_control *sc)
    {
    sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC;
    }

    shrink_page_list()
    {
    (snip)
    activate_locked:
    SetPageActive(page);
    pgactivate++;
    unlock_page(page);
    reset_reclaim_mode(sc); /// here
    list_add(&page->lru, &ret_pages);
    }
    -----------------------------------------------------------------------------------------------------


    -----------------------------------------------------------------------------------------------------
    bool should_reclaim_stall()
    {
    (snip)

    /* Only stall on lumpy reclaim */
    if (sc->reclaim_mode & RECLAIM_MODE_SINGLE) /// and here
    return false;
    -----------------------------------------------------------------------------------------------------
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