mm/debug.c: PageAnon() is true for PageKsm() pages
PageAnon() and PageKsm() use the low two bits of the page->mapping
pointer to indicate the page type. PageAnon() only checks the LSB while
PageKsm() checks the least significant 2 bits are equal to 3.
Therefore, PageAnon() is true for KSM pages. __dump_page() incorrectly
will never print "ksm" because it checks PageAnon() first. Fix this by
checking PageKsm() first.
Link: http://lkml.kernel.org/r/20191113000651.20677-1-rcampbell@nvidia.com
Fixes: 1c6fb1d89e73 ("mm: print more information about mapping in __dump_page")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/debug.c b/mm/debug.c
index 772d4cf..0461df1 100644
--- a/mm/debug.c
+++ b/mm/debug.c
@@ -77,10 +77,10 @@ void __dump_page(struct page *page, const char *reason)
pr_warn("page:%px refcount:%d mapcount:%d mapping:%px index:%#lx\n",
page, page_ref_count(page), mapcount,
page->mapping, page_to_pgoff(page));
- if (PageAnon(page))
- pr_warn("anon flags: %#lx(%pGp)\n", page->flags, &page->flags);
- else if (PageKsm(page))
+ if (PageKsm(page))
pr_warn("ksm flags: %#lx(%pGp)\n", page->flags, &page->flags);
+ else if (PageAnon(page))
+ pr_warn("anon flags: %#lx(%pGp)\n", page->flags, &page->flags);
else if (mapping) {
if (mapping->host && mapping->host->i_dentry.first) {
struct dentry *dentry;
