Re: [PATCH -V6 02/14] hugetlbfs: don't use ERR_PTR with VM_FAULT*values

From: David Rientjes
Date: Thu May 24 2012 - 17:17:42 EST


On Mon, 16 Apr 2012, Aneesh Kumar K.V wrote:

> From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
>
> Using VM_FAULT_* codes with ERR_PTR will require us to make sure
> VM_FAULT_* values will not exceed MAX_ERRNO value.
>

Is it worth the extra branches?

> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
> ---
> mm/hugetlb.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 766eb90..5a472a5 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1123,10 +1123,10 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> */
> chg = vma_needs_reservation(h, vma, addr);
> if (chg < 0)
> - return ERR_PTR(-VM_FAULT_OOM);
> + return ERR_PTR(-ENOMEM);
> if (chg)
> if (hugepage_subpool_get_pages(spool, chg))
> - return ERR_PTR(-VM_FAULT_SIGBUS);
> + return ERR_PTR(-ENOSPC);
>
> spin_lock(&hugetlb_lock);
> page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
> @@ -1136,7 +1136,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
> page = alloc_buddy_huge_page(h, NUMA_NO_NODE);
> if (!page) {
> hugepage_subpool_put_pages(spool, chg);
> - return ERR_PTR(-VM_FAULT_SIGBUS);
> + return ERR_PTR(-ENOSPC);
> }
> }
>
> @@ -2486,6 +2486,7 @@ retry_avoidcopy:
> new_page = alloc_huge_page(vma, address, outside_reserve);
>
> if (IS_ERR(new_page)) {
> + int err = PTR_ERR(new_page);
> page_cache_release(old_page);
>
> /*

PTR_ERR() returns long.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/