Commit 82a3241a authored by Wei Yang's avatar Wei Yang Committed by Linus Torvalds
Browse files

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



After commit 5b57b8f2 ("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: default avatarAnshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: default avatarWei Yang <richard.weiyang@gmail.com>
Signed-off-by: default avatarAndrew 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: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 833d8a42

mm/page_alloc.c

+10 −24
Original line number Diff line number Diff line
@@ -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);

}



/*