From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Subject: mm/memcg: add debug checking in lock_page_memcg Add a debug checking in lock_page_memcg, then we could get alarm if anything wrong here. Link: https://lkml.kernel.org/r/1604566549-62481-9-git-send-email-alex.shi@xxxxxxxxxxxxxxxxx Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> 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: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> 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: Vlastimil Babka <vbabka@xxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/mm/memcontrol.c~mm-memcg-add-debug-checking-in-lock_page_memcg +++ a/mm/memcontrol.c @@ -2150,6 +2150,12 @@ again: if (unlikely(!memcg)) return NULL; +#ifdef CONFIG_PROVE_LOCKING + local_irq_save(flags); + might_lock(&memcg->move_lock); + local_irq_restore(flags); +#endif + if (atomic_read(&memcg->moving_account) <= 0) return memcg; _
