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mm, debug: move bad flags printing to bad_page()
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Since bad_page() is the only user of the badflags parameter of
dump_page_badflags(), we can move the code to bad_page() and simplify a
bit.

The dump_page_badflags() function is renamed to __dump_page() and can
still be called separately from dump_page() for temporary debug prints
where page_owner info is not desired.

The only user-visible change is that page->mem_cgroup is printed before
the bad flags.

Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Sasha Levin <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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tehcaster authored and torvalds committed Mar 15, 2016
1 parent 4e46211 commit ff8e811
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Showing 3 changed files with 11 additions and 12 deletions.
3 changes: 1 addition & 2 deletions include/linux/mmdebug.h
Original file line number Diff line number Diff line change
Expand Up @@ -9,8 +9,7 @@ struct vm_area_struct;
struct mm_struct;

extern void dump_page(struct page *page, const char *reason);
extern void dump_page_badflags(struct page *page, const char *reason,
unsigned long badflags);
extern void __dump_page(struct page *page, const char *reason);
void dump_vma(const struct vm_area_struct *vma);
void dump_mm(const struct mm_struct *mm);

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10 changes: 3 additions & 7 deletions mm/debug.c
Original file line number Diff line number Diff line change
Expand Up @@ -40,8 +40,7 @@ const struct trace_print_flags vmaflag_names[] = {
{0, NULL}
};

void dump_page_badflags(struct page *page, const char *reason,
unsigned long badflags)
void __dump_page(struct page *page, const char *reason)
{
pr_emerg("page:%p count:%d mapcount:%d mapping:%p index:%#lx",
page, atomic_read(&page->_count), page_mapcount(page),
Expand All @@ -50,15 +49,12 @@ void dump_page_badflags(struct page *page, const char *reason,
pr_cont(" compound_mapcount: %d", compound_mapcount(page));
pr_cont("\n");
BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);

pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags);

if (reason)
pr_alert("page dumped because: %s\n", reason);

badflags &= page->flags;
if (badflags)
pr_alert("bad because of flags: %#lx(%pGp)\n", badflags,
&badflags);
#ifdef CONFIG_MEMCG
if (page->mem_cgroup)
pr_alert("page->mem_cgroup:%p\n", page->mem_cgroup);
Expand All @@ -67,7 +63,7 @@ void dump_page_badflags(struct page *page, const char *reason,

void dump_page(struct page *page, const char *reason)
{
dump_page_badflags(page, reason, 0);
__dump_page(page, reason);
dump_page_owner(page);
}
EXPORT_SYMBOL(dump_page);
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10 changes: 7 additions & 3 deletions mm/page_alloc.c
Original file line number Diff line number Diff line change
Expand Up @@ -430,7 +430,7 @@ static void bad_page(struct page *page, const char *reason,
goto out;
}
if (nr_unshown) {
printk(KERN_ALERT
pr_alert(
"BUG: Bad page state: %lu messages suppressed\n",
nr_unshown);
nr_unshown = 0;
Expand All @@ -440,9 +440,13 @@ static void bad_page(struct page *page, const char *reason,
if (nr_shown++ == 0)
resume = jiffies + 60 * HZ;

printk(KERN_ALERT "BUG: Bad page state in process %s pfn:%05lx\n",
pr_alert("BUG: Bad page state in process %s pfn:%05lx\n",
current->comm, page_to_pfn(page));
dump_page_badflags(page, reason, bad_flags);
__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();
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