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Subject[Patch v2 3/4] mm/page_alloc.c: pass all bad reasons to bad_page()
Date
Now we can pass all bad reasons to __dump_page().

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
mm/page_alloc.c | 52 ++++++++++++++++++++++++++-----------------------
1 file changed, 28 insertions(+), 24 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a43b9d2482f2..a7b793c739fc 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -609,7 +609,7 @@ static inline int __maybe_unused bad_range(struct zone *zone, struct page *page)
}
#endif

-static void bad_page(struct page *page, const char *reason,
+static void bad_page(struct page *page, int nr, const char **reason,
unsigned long bad_flags)
{
static unsigned long resume;
@@ -638,7 +638,7 @@ 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, 1, &reason);
+ __dump_page(page, nr, reason);
bad_flags &= page->flags;
if (bad_flags)
pr_alert("bad because of flags: %#lx(%pGp)\n",
@@ -1027,27 +1027,25 @@ 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[5];
+ unsigned long bad_flags = 0;
+ int nr = 0;

if (unlikely(atomic_read(&page->_mapcount) != -1))
- bad_reason = "nonzero mapcount";
+ bad_reason[nr++] = "nonzero mapcount";
if (unlikely(page->mapping != NULL))
- bad_reason = "non-NULL mapping";
+ bad_reason[nr++] = "non-NULL mapping";
if (unlikely(page_ref_count(page) != 0))
- bad_reason = "nonzero _refcount";
+ bad_reason[nr++] = "nonzero _refcount";
if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
- bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
+ bad_reason[nr++] = "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";
+ bad_reason[nr++] = "page still charged to cgroup";
#endif
- bad_page(page, bad_reason, bad_flags);
+ bad_page(page, nr, bad_reason, bad_flags);
}

static inline int free_pages_check(struct page *page)
@@ -1062,6 +1060,7 @@ static inline int free_pages_check(struct page *page)

static int free_tail_pages_check(struct page *head_page, struct page *page)
{
+ const char *reason;
int ret = 1;

/*
@@ -1078,7 +1077,8 @@ 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);
+ reason = "nonzero compound_mapcount";
+ bad_page(page, 1, &reason, 0);
goto out;
}
break;
@@ -1090,17 +1090,20 @@ 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);
+ reason = "corrupted mapping in tail page";
+ bad_page(page, 1, &reason, 0);
goto out;
}
break;
}
if (unlikely(!PageTail(page))) {
- bad_page(page, "PageTail not set", 0);
+ reason = "PageTail not set";
+ bad_page(page, 1, &reason, 0);
goto out;
}
if (unlikely(compound_head(page) != head_page)) {
- bad_page(page, "compound_head not consistent", 0);
+ reason = "compound_head not consistent";
+ bad_page(page, 1, &reason, 0);
goto out;
}
ret = 0;
@@ -2041,29 +2044,30 @@ static inline void expand(struct zone *zone, struct page *page,

static void check_new_page_bad(struct page *page)
{
- const char *bad_reason = NULL;
+ const char *bad_reason[5];
unsigned long bad_flags = 0;
+ int nr = 0;

if (unlikely(atomic_read(&page->_mapcount) != -1))
- bad_reason = "nonzero mapcount";
+ bad_reason[nr++] = "nonzero mapcount";
if (unlikely(page->mapping != NULL))
- bad_reason = "non-NULL mapping";
+ bad_reason[nr++] = "non-NULL mapping";
if (unlikely(page_ref_count(page) != 0))
- bad_reason = "nonzero _refcount";
+ bad_reason[nr++] = "nonzero _refcount";
if (unlikely(page->flags & __PG_HWPOISON)) {
/* Don't complain about hwpoisoned pages */
page_mapcount_reset(page); /* remove PageBuddy */
return;
}
if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
- bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
+ bad_reason[nr++] = "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";
+ bad_reason[nr++] = "page still charged to cgroup";
#endif
- bad_page(page, bad_reason, bad_flags);
+ bad_page(page, 1, bad_reason, bad_flags);
}

/*
--
2.17.1
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