tree 5e367fb51a8d1168511e3c17054c65b7b90f0c97
parent 24284d5f53d0d8d4bc9321cfbd23f7bd63480059
author Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 1521760651 -0700
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1522255161 +0200

mm/thp: do not wait for lock_page() in deferred_split_scan()

commit fa41b900c30b45fab03783724932dc30cd46a6be upstream.

deferred_split_scan() gets called from reclaim path.  Waiting for page
lock may lead to deadlock there.

Replace lock_page() with trylock_page() and skip the page if we failed
to lock it.  We will get to the page on the next scan.

Link: http://lkml.kernel.org/r/20180315150747.31945-1-kirill.shutemov@linux.intel.com
Fixes: 9a982250f773 ("thp: introduce deferred_split_huge_page()")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>