mm/page_alloc.c: bad_flags is not necessary for bad_page()

After commit 5b57b8f22709 ("mm/debug.c: always print flags in
dump_page()"), page->flags is always printed for a bad page.  It is not
necessary to have bad_flags any more.

Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200411220357.9636-3-richard.weiyang@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3ef7db15ec70d3842ad9dda82d99b8f8275272bb..895d85525919409d1982bf768ac62e82c1561405 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -607,8 +607,7 @@ static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
 }
 #endif
 
-static void bad_page(struct page *page, const char *reason,
-               unsigned long bad_flags)
+static void bad_page(struct page *page, const char *reason)
 {
        static unsigned long resume;
        static unsigned long nr_shown;
@@ -637,10 +636,6 @@ static void bad_page(struct page *page, const char *reason,
        pr_alert("BUG: Bad page state in process %s  pfn:%05lx\n",
                current->comm, page_to_pfn(page));
        __dump_page(page, reason);
-       bad_flags &= page->flags;
-       if (bad_flags)
-               pr_alert("bad because of flags: %#lx(%pGp)\n",
-                                               bad_flags, &bad_flags);
        dump_page_owner(page);
 
        print_modules();
@@ -1077,11 +1072,7 @@ static inline bool page_expected_state(struct page *page,
 
 static void free_pages_check_bad(struct page *page)
 {
-       const char *bad_reason;
-       unsigned long bad_flags;
-
-       bad_reason = NULL;
-       bad_flags = 0;
+       const char *bad_reason = NULL;
 
        if (unlikely(atomic_read(&page->_mapcount) != -1))
                bad_reason = "nonzero mapcount";
@@ -1089,15 +1080,13 @@ static void free_pages_check_bad(struct page *page)
                bad_reason = "non-NULL mapping";
        if (unlikely(page_ref_count(page) != 0))
                bad_reason = "nonzero _refcount";
-       if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
+       if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE))
                bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
-               bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
-       }
 #ifdef CONFIG_MEMCG
        if (unlikely(page->mem_cgroup))
                bad_reason = "page still charged to cgroup";
 #endif
-       bad_page(page, bad_reason, bad_flags);
+       bad_page(page, bad_reason);
 }
 
 static inline int free_pages_check(struct page *page)
@@ -1128,7 +1117,7 @@ static int free_tail_pages_check(struct page *head_page, struct page *page)
        case 1:
                /* the first tail page: ->mapping may be compound_mapcount() */
                if (unlikely(compound_mapcount(page))) {
-                       bad_page(page, "nonzero compound_mapcount", 0);
+                       bad_page(page, "nonzero compound_mapcount");
                        goto out;
                }
                break;
@@ -1140,17 +1129,17 @@ static int free_tail_pages_check(struct page *head_page, struct page *page)
                break;
        default:
                if (page->mapping != TAIL_MAPPING) {
-                       bad_page(page, "corrupted mapping in tail page", 0);
+                       bad_page(page, "corrupted mapping in tail page");
                        goto out;
                }
                break;
        }
        if (unlikely(!PageTail(page))) {
-               bad_page(page, "PageTail not set", 0);
+               bad_page(page, "PageTail not set");
                goto out;
        }
        if (unlikely(compound_head(page) != head_page)) {
-               bad_page(page, "compound_head not consistent", 0);
+               bad_page(page, "compound_head not consistent");
                goto out;
        }
        ret = 0;
@@ -2095,7 +2084,6 @@ static inline void expand(struct zone *zone, struct page *page,
 static void check_new_page_bad(struct page *page)
 {
        const char *bad_reason = NULL;
-       unsigned long bad_flags = 0;
 
        if (unlikely(page->flags & __PG_HWPOISON)) {
                /* Don't complain about hwpoisoned pages */
@@ -2108,15 +2096,13 @@ static void check_new_page_bad(struct page *page)
                bad_reason = "non-NULL mapping";
        if (unlikely(page_ref_count(page) != 0))
                bad_reason = "nonzero _refcount";
-       if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
+       if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP))
                bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
-               bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
-       }
 #ifdef CONFIG_MEMCG
        if (unlikely(page->mem_cgroup))
                bad_reason = "page still charged to cgroup";
 #endif
-       bad_page(page, bad_reason, bad_flags);
+       bad_page(page, bad_reason);
 }
 
 /*