From: Johannes Weiner <hannes@xxxxxxxxxxx> Subject: Revert "mm, vmscan: account for skipped pages as a partial scan" 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. Link: http://lkml.kernel.org/r/20170228214007.5621-9-hannes@xxxxxxxxxxx Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: Jia He <hejianet@xxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 22 ++++------------------ 1 file changed, 4 insertions(+), 18 deletions(-) diff -puN mm/vmscan.c~revert-mm-vmscan-account-for-skipped-pages-as-a-partial-scan mm/vmscan.c --- a/mm/vmscan.c~revert-mm-vmscan-account-for-skipped-pages-as-a-partial-scan +++ a/mm/vmscan.c @@ -1472,12 +1472,12 @@ static unsigned long isolate_lru_pages(u 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); @@ -1491,12 +1491,6 @@ static unsigned long isolate_lru_pages(u 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); @@ -1525,6 +1519,7 @@ static unsigned long isolate_lru_pages(u 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; @@ -1532,17 +1527,8 @@ static unsigned long isolate_lru_pages(u __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); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
