| Message ID | 20220823030209.57434-4-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | A few fixup patches for hugetlb | expand |
On 08/23/22 11:02, Miaohe Lin wrote: > When huge_add_to_page_cache() fails, the page is freed directly without > calling restore_reserve_on_error() to restore reserve for newly allocated > pages not in page cache. Fix this by calling restore_reserve_on_error() > when huge_add_to_page_cache fails. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > mm/hugetlb.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index d46dfe5ba62c..8e62da153c64 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -5576,7 +5576,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, > if (idx >= size) > goto out; > > -retry: > new_page = false; > page = find_lock_page(mapping, idx); > if (!page) { > @@ -5616,9 +5615,15 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, > if (vma->vm_flags & VM_MAYSHARE) { > int err = huge_add_to_page_cache(page, mapping, idx); > if (err) { > + /* > + * err can't be -EEXIST which implies someone > + * else consumed the reservation since hugetlb > + * fault mutex is held when add a hugetlb page > + * to the page cache. So it's safe to call > + * restore_reserve_on_error() here. > + */ > + restore_reserve_on_error(h, vma, haddr, page); > put_page(page); > - if (err == -EEXIST) > - goto retry; Thanks for removing this check and adding the comment. Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index d46dfe5ba62c..8e62da153c64 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5576,7 +5576,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, if (idx >= size) goto out; -retry: new_page = false; page = find_lock_page(mapping, idx); if (!page) { @@ -5616,9 +5615,15 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, if (vma->vm_flags & VM_MAYSHARE) { int err = huge_add_to_page_cache(page, mapping, idx); if (err) { + /* + * err can't be -EEXIST which implies someone + * else consumed the reservation since hugetlb + * fault mutex is held when add a hugetlb page + * to the page cache. So it's safe to call + * restore_reserve_on_error() here. + */ + restore_reserve_on_error(h, vma, haddr, page); put_page(page); - if (err == -EEXIST) - goto retry; goto out; } new_pagecache_page = true;
When huge_add_to_page_cache() fails, the page is freed directly without calling restore_reserve_on_error() to restore reserve for newly allocated pages not in page cache. Fix this by calling restore_reserve_on_error() when huge_add_to_page_cache fails. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- mm/hugetlb.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)