lkml.org 
[lkml]   [2017]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 8/9] Revert "mm, vmscan: account for skipped pages as a partial scan"
    On Tue 28-02-17 16:40:06, Johannes Weiner wrote:
    > This reverts commit d7f05528eedb047efe2288cff777676b028747b6.
    >
    > Now that reclaimability of a node is no longer based on the ratio
    > between pages scanned and theoretically reclaimable pages, we can
    > remove accounting tricks for pages skipped due to zone constraints.
    >
    > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

    Acked-by: Michal Hocko <mhocko@suse.com>

    > ---
    > mm/vmscan.c | 22 ++++------------------
    > 1 file changed, 4 insertions(+), 18 deletions(-)
    >
    > diff --git a/mm/vmscan.c b/mm/vmscan.c
    > index 35b791a8922b..ddcff8a11c1e 100644
    > --- a/mm/vmscan.c
    > +++ b/mm/vmscan.c
    > @@ -1471,12 +1471,12 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
    > unsigned long nr_taken = 0;
    > unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 };
    > unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
    > - unsigned long skipped = 0, total_skipped = 0;
    > + unsigned long skipped = 0;
    > unsigned long scan, nr_pages;
    > LIST_HEAD(pages_skipped);
    >
    > for (scan = 0; scan < nr_to_scan && nr_taken < nr_to_scan &&
    > - !list_empty(src);) {
    > + !list_empty(src); scan++) {
    > struct page *page;
    >
    > page = lru_to_page(src);
    > @@ -1490,12 +1490,6 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
    > continue;
    > }
    >
    > - /*
    > - * Account for scanned and skipped separetly to avoid the pgdat
    > - * being prematurely marked unreclaimable by pgdat_reclaimable.
    > - */
    > - scan++;
    > -
    > switch (__isolate_lru_page(page, mode)) {
    > case 0:
    > nr_pages = hpage_nr_pages(page);
    > @@ -1524,6 +1518,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
    > if (!list_empty(&pages_skipped)) {
    > int zid;
    >
    > + list_splice(&pages_skipped, src);
    > for (zid = 0; zid < MAX_NR_ZONES; zid++) {
    > if (!nr_skipped[zid])
    > continue;
    > @@ -1531,17 +1526,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
    > __count_zid_vm_events(PGSCAN_SKIP, zid, nr_skipped[zid]);
    > skipped += nr_skipped[zid];
    > }
    > -
    > - /*
    > - * Account skipped pages as a partial scan as the pgdat may be
    > - * close to unreclaimable. If the LRU list is empty, account
    > - * skipped pages as a full scan.
    > - */
    > - total_skipped = list_empty(src) ? skipped : skipped >> 2;
    > -
    > - list_splice(&pages_skipped, src);
    > }
    > - *nr_scanned = scan + total_skipped;
    > + *nr_scanned = scan;
    > trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan,
    > scan, skipped, nr_taken, mode, lru);
    > update_lru_sizes(lruvec, lru, nr_zone_taken);
    > --
    > 2.11.1

    --
    Michal Hocko
    SUSE Labs

    \
     
     \ /
      Last update: 2017-03-01 16:52    [W:4.848 / U:0.224 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site