On Mon 14-01-19 19:20:24, Kirill Tkhai wrote:
> We may simply check for sc->may_unmap in isolate_lru_pages()
> instead of doing that in both of its callers.
This code seems stale for a long time. AFAICS 1276ad68e249 ("mm: vmscan:
scan dirty pages even in laptop mode") has removed ISOLATE_CLEAN and
there was no other mode besides that and ISOLATE_UNMAPPED.
> Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> mm/vmscan.c | 15 ++++-----------
> 1 file changed, 4 insertions(+), 11 deletions(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index a714c4f800e9..8202f8eb602d 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -1663,7 +1663,7 @@ static __always_inline void update_lru_sizes(struct lruvec *lruvec,
> static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
> struct lruvec *lruvec, struct list_head *dst,
> unsigned long *nr_scanned, struct scan_control *sc,
> - isolate_mode_t mode, enum lru_list lru)
> + enum lru_list lru)
> {
> struct list_head *src = &lruvec->lists[lru];
> unsigned long nr_taken = 0;
> @@ -1672,6 +1672,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
> unsigned long skipped = 0;
> unsigned long scan, total_scan, nr_pages;
> LIST_HEAD(pages_skipped);
> + isolate_mode_t mode = (sc->may_unmap ? 0 : ISOLATE_UNMAPPED);
>
> scan = 0;
> for (total_scan = 0;
> @@ -1910,7 +1911,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
> unsigned long nr_reclaimed = 0;
> unsigned long nr_taken;
> struct reclaim_stat stat = {};
> - isolate_mode_t isolate_mode = 0;
> int file = is_file_lru(lru);
> struct pglist_data *pgdat = lruvec_pgdat(lruvec);
> struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
> @@ -1931,13 +1931,10 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
>
> lru_add_drain();
>
> - if (!sc->may_unmap)
> - isolate_mode |= ISOLATE_UNMAPPED;
> -
> spin_lock_irq(&pgdat->lru_lock);
>
> nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &page_list,
> - &nr_scanned, sc, isolate_mode, lru);
> + &nr_scanned, sc, lru);
>
> __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken);
> reclaim_stat->recent_scanned[file] += nr_taken;
> @@ -2094,19 +2091,15 @@ static void shrink_active_list(unsigned long nr_to_scan,
> struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
> unsigned nr_deactivate, nr_activate;
> unsigned nr_rotated = 0;
> - isolate_mode_t isolate_mode = 0;
> int file = is_file_lru(lru);
> struct pglist_data *pgdat = lruvec_pgdat(lruvec);
>
> lru_add_drain();
>
> - if (!sc->may_unmap)
> - isolate_mode |= ISOLATE_UNMAPPED;
> -
> spin_lock_irq(&pgdat->lru_lock);
>
> nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &l_hold,
> - &nr_scanned, sc, isolate_mode, lru);
> + &nr_scanned, sc, lru);
>
> __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken);
> reclaim_stat->recent_scanned[file] += nr_taken;
>
--
Michal Hocko
SUSE Labs
