Re: [PATCH -V8 02/16] hugetlb: don't use ERR_PTR with VM_FAULT* values
From: Konrad Rzeszutek Wilk <hidden>
Date: 2012-06-09 11:10:23
Also in:
linux-mm, lkml
On Sat, Jun 09, 2012 at 02:29:47PM +0530, Aneesh Kumar K.V wrote:
From: "Aneesh Kumar K.V" <redacted> The current use of VM_FAULT_* codes with ERR_PTR requires us to ensure VM_FAULT_* values will not exceed MAX_ERRNO value. Decouple the VM_FAULT_* values from MAX_ERRNO.
I see you using the -ENOMEM|-ENOSPC, but I don't see any reference in the code to MAX_ERRNO? Can you provide a comment explaining in a tad little bit about the interaction of MAX_ERRNO and VM_FAULT?
quoted hunk ↗ jump to hunk
Reviewed-by: KAMEZAWA Hiroyuki <redacted> Signed-off-by: Aneesh Kumar K.V <redacted> --- mm/hugetlb.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)diff --git a/mm/hugetlb.c b/mm/hugetlb.c index c868309..34a7e23 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); } }@@ -2496,6 +2496,7 @@ retry_avoidcopy: new_page = alloc_huge_page(vma, address, outside_reserve); if (IS_ERR(new_page)) { + long err = PTR_ERR(new_page); page_cache_release(old_page); /*@@ -2524,7 +2525,10 @@ retry_avoidcopy: /* Caller expects lock to be held */ spin_lock(&mm->page_table_lock); - return -PTR_ERR(new_page); + if (err == -ENOMEM) + return VM_FAULT_OOM; + else + return VM_FAULT_SIGBUS; } /*@@ -2642,7 +2646,11 @@ retry: goto out; page = alloc_huge_page(vma, address, 0); if (IS_ERR(page)) { - ret = -PTR_ERR(page); + ret = PTR_ERR(page); + if (ret == -ENOMEM) + ret = VM_FAULT_OOM; + else + ret = VM_FAULT_SIGBUS; goto out; } clear_huge_page(page, address, pages_per_huge_page(h));-- 1.7.10 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
-- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>