From: Hugh Dickins <hughd(a)google.com>
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(a)google.com>
Acked-by: Michal Hocko <mhocko(a)suse.com>
Cc: David Rientjes <rientjes(a)google.com>
Cc: Gerald Schaefer <gerald.schaefer(a)de.ibm.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: <stable(a)vger.kernel.org> # 4.9.x
Reported-by: Chen si <cici.cs(a)alibaba-inc.com>
Signed-off-by: Baoyou Xie <baoyou.xie(a)aliyun.com>
Signed-off-by: Wen Yang <wenyang(a)linux.alibaba.com>
Signed-off-by: Zijiang Huang <zijiang.hzj(a)alibaba-inc.com>
---
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