From: Hugh Dickins <hughd@xxxxxxxxxx> commit a66c0410b97c07a5708881198528ce724f7a3226 upstream. The other pagetable walks in task_mmu.c have a cond_resched() after walking their ptes: add a cond_resched() in gather_pte_stats() too, for reading /proc/<id>/numa_maps. Only pagemap_pmd_range() has a cond_resched() in its (unusually expensive) pmd_trans_huge case: more should probably be added, but leave them unchanged for now. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052157400.13021@eggly.anvils Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 4.9.x Reported-by: Chen si <cici.cs@xxxxxxxxxxxxxxx> Signed-off-by: Baoyou Xie <baoyou.xie@xxxxxxxxxx> Signed-off-by: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx> Signed-off-by: Zijiang Huang <zijiang.hzj@xxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 4b207b1..e6c8ead 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1609,6 +1609,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr, } while (pte++, addr += PAGE_SIZE, addr != end); pte_unmap_unlock(orig_pte, ptl); + cond_resched(); return 0; } #ifdef CONFIG_HUGETLB_PAGE -- 1.8.3.1
