korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-23 12:14:10 +08:00
Code Issues Packages Projects Releases Wiki Activity

mm/swapfile: skip HugeTLB pages for unuse_vma

Browse Source 
I got a bad pud error and lost a 1GB HugeTLB when calling swapoff.  The
problem can be reproduced by the following steps:

 1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory.
 2. Swapout the above anonymous memory.
 3. run swapoff and we will get a bad pud error in kernel message:

  mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7)

We can tell that pud_clear_bad is called by pud_none_or_clear_bad in
unuse_pud_range() by ftrace.  And therefore the HugeTLB pages will never
be freed because we lost it from page table.  We can skip HugeTLB pages
for unuse_vma to fix it.

Link: https://lkml.kernel.org/r/20241015014521.570237-1-liushixin2@huawei.com
Fixes: 0fe6e20b9c ("hugetlb, rmap: add reverse mapping for hugepage")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liu Shixin 2024-10-15 09:45:21 +08:00 committed by Andrew Morton
parent 3e822bed2f
commit 7528c4fb12
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
mm/swapfile.c
View File

@ -2313,7 +2313,7 @@ static int unuse_mm(struct mm_struct *mm, unsigned int type)
mmap_read_lock(mm);
for_each_vma(vmi, vma) {
if (vma->anon_vma) {
if (vma->anon_vma && !is_vm_hugetlb_page(vma)) {
ret = unuse_vma(vma, type);
if (ret)
break;