From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Subject: mm/vmscan: remove lruvec reget in move_pages_to_lru Isolated page shouldn't be recharged by memcg since the memcg migration isn't possible at the time. All pages were isolated from the same lruvec (and isolation inhibits memcg migration). So remove unnecessary regetting. Thanks to Alexander Duyck for pointing this out. Link: https://lkml.kernel.org/r/1604566549-62481-12-git-send-email-alex.shi@xxxxxxxxxxxxxxxxx Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Alexander Duyck <alexander.duyck@xxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: "Chen, Rong A" <rong.a.chen@xxxxxxxxx> Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> Cc: "Huang, Ying" <ying.huang@xxxxxxxxx> Cc: Jann Horn <jannh@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Mika Penttilä <mika.penttila@xxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/mm/vmscan.c~mm-vmscan-remove-lruvec-reget-in-move_pages_to_lru +++ a/mm/vmscan.c @@ -1886,7 +1886,12 @@ static unsigned noinline_for_stack move_ continue; } - lruvec = mem_cgroup_page_lruvec(page, pgdat); + /* + * All pages were isolated from the same lruvec (and isolation + * inhibits memcg migration). + */ + VM_BUG_ON_PAGE(mem_cgroup_page_lruvec(page, page_pgdat(page)) + != lruvec, page); lru = page_lru(page); nr_pages = thp_nr_pages(page); _
