hugetlb: add an inline helper for finding hstate index

Add an inline helper and use it in the code.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index d5d6bbe..217f528 100644 (file)
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -302,6 +302,11 @@ static inline unsigned hstate_index_to_shift(unsigned index)
        return hstates[index].order + PAGE_SHIFT;
 }
 
+static inline int hstate_index(struct hstate *h)
+{
+       return h - hstates;
+}
+
 #else
 struct hstate {};
 #define alloc_huge_page_node(h, nid) NULL
@@ -320,6 +325,7 @@ static inline unsigned int pages_per_huge_page(struct hstate *h)
        return 1;
 }
 #define hstate_index_to_shift(index) 0
+#define hstate_index(h) 0
 #endif
 
 #endif /* _LINUX_HUGETLB_H */

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 34a7e23..b1e0ed1 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1646,7 +1646,7 @@ static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
                                    struct attribute_group *hstate_attr_group)
 {
        int retval;
-       int hi = h - hstates;
+       int hi = hstate_index(h);
 
        hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
        if (!hstate_kobjs[hi])
@@ -1741,11 +1741,13 @@ void hugetlb_unregister_node(struct node *node)
        if (!nhs->hugepages_kobj)
                return;         /* no hstate attributes */
 
-       for_each_hstate(h)
-               if (nhs->hstate_kobjs[h - hstates]) {
-                       kobject_put(nhs->hstate_kobjs[h - hstates]);
-                       nhs->hstate_kobjs[h - hstates] = NULL;
+       for_each_hstate(h) {
+               int idx = hstate_index(h);
+               if (nhs->hstate_kobjs[idx]) {
+                       kobject_put(nhs->hstate_kobjs[idx]);
+                       nhs->hstate_kobjs[idx] = NULL;
                }
+       }
 
        kobject_put(nhs->hugepages_kobj);
        nhs->hugepages_kobj = NULL;
@@ -1848,7 +1850,7 @@ static void __exit hugetlb_exit(void)
        hugetlb_unregister_all_nodes();
 
        for_each_hstate(h) {
-               kobject_put(hstate_kobjs[h - hstates]);
+               kobject_put(hstate_kobjs[hstate_index(h)]);
        }
 
        kobject_put(hugepages_kobj);
@@ -1869,7 +1871,7 @@ static int __init hugetlb_init(void)
                if (!size_to_hstate(default_hstate_size))
                        hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
        }
-       default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
+       default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size));
        if (default_hstate_max_huge_pages)
                default_hstate.max_huge_pages = default_hstate_max_huge_pages;
 
@@ -2687,7 +2689,7 @@ retry:
                 */
                if (unlikely(PageHWPoison(page))) {
                        ret = VM_FAULT_HWPOISON |
-                             VM_FAULT_SET_HINDEX(h - hstates);
+                               VM_FAULT_SET_HINDEX(hstate_index(h));
                        goto backout_unlocked;
                }
        }
@@ -2760,7 +2762,7 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                        return 0;
                } else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
                        return VM_FAULT_HWPOISON_LARGE |
-                              VM_FAULT_SET_HINDEX(h - hstates);
+                               VM_FAULT_SET_HINDEX(hstate_index(h));
        }
 
        ptep = huge_pte_alloc(mm, address, huge_page_size(h));