On 1/3/21 10:58 PM, Muchun Song wrote: > Because we only can isolate a active page via isolate_huge_page() > and hugetlbfs_fallocate() forget to mark it as active, we cannot > isolate and migrate those pages. > > Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate()) > Signed-off-by: Muchun Song <songmuc...@bytedance.com> > --- > fs/hugetlbfs/inode.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-)
Good catch. This is indeed an issue. > > diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c > index b5c109703daa..2aceb085d202 100644 > --- a/fs/hugetlbfs/inode.c > +++ b/fs/hugetlbfs/inode.c > @@ -737,10 +737,11 @@ static long hugetlbfs_fallocate(struct file *file, int > mode, loff_t offset, > > /* > * unlock_page because locked by add_to_page_cache() > - * page_put due to reference from alloc_huge_page() > + * put_page() (which is in the putback_active_hugepage()) > + * due to reference from alloc_huge_page() Thanks for fixing the comment. > */ > unlock_page(page); > - put_page(page); > + putback_active_hugepage(page); I'm curious why you used putback_active_hugepage() here instead of simply calling set_page_huge_active() before the put_page()? When the page was allocated, it was placed on the active list (alloc_huge_page). Therefore, the hugetlb_lock locking and list movement should not be necessary. -- Mike Kravetz > } > > if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) >
