memcg: fix leak of accounting at failure path of hugepage collapsing
mem_cgroup_uncharge_page() should be called in all failure cases after
mem_cgroup_charge_newpage() is called in huge_memory.c::collapse_huge_page()
[ 4209.076861] BUG: Bad page state in process khugepaged pfn:1e9800
[ 4209.077601] page:ffffea0006b14000 count:0 mapcount:0 mapping: (null) index:0x2800
[ 4209.078674] page flags: 0x40000000004000(head)
[ 4209.079294] pc:ffff880214a30000 pc->flags:2146246697418756 pc->mem_cgroup:ffffc9000177a000
[ 4209.082177] (/A)
[ 4209.082500] Pid: 31, comm: khugepaged Not tainted 2.6.38-rc3-mm1 #1
[ 4209.083412] Call Trace:
[ 4209.083678] [<ffffffff810f4454>] ? bad_page+0xe4/0x140
[ 4209.084240] [<ffffffff810f53e6>] ? free_pages_prepare+0xd6/0x120
[ 4209.084837] [<ffffffff8155621d>] ? rwsem_down_failed_common+0xbd/0x150
[ 4209.085509] [<ffffffff810f5462>] ? __free_pages_ok+0x32/0xe0
[ 4209.086110] [<ffffffff810f552b>] ? free_compound_page+0x1b/0x20
[ 4209.086699] [<ffffffff810fad6c>] ? __put_compound_page+0x1c/0x30
[ 4209.087333] [<ffffffff810fae1d>] ? put_compound_page+0x4d/0x200
[ 4209.087935] [<ffffffff810fb015>] ? put_page+0x45/0x50
[ 4209.097361] [<ffffffff8113f779>] ? khugepaged+0x9e9/0x1430
[ 4209.098364] [<ffffffff8107c870>] ? autoremove_wake_function+0x0/0x40
[ 4209.099121] [<ffffffff8113ed90>] ? khugepaged+0x0/0x1430
[ 4209.099780] [<ffffffff8107c236>] ? kthread+0x96/0xa0
[ 4209.100452] [<ffffffff8100dda4>] ? kernel_thread_helper+0x4/0x10
[ 4209.101214] [<ffffffff8107c1a0>] ? kthread+0x0/0xa0
[ 4209.101842] [<ffffffff8100dda0>] ? kernel_thread_helper+0x0/0x10
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b6c1ce3..e62ddb8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1852,7 +1852,6 @@
set_pmd_at(mm, address, pmd, _pmd);
spin_unlock(&mm->page_table_lock);
anon_vma_unlock(vma->anon_vma);
- mem_cgroup_uncharge_page(new_page);
goto out;
}
@@ -1898,6 +1897,7 @@
return;
out:
+ mem_cgroup_uncharge_page(new_page);
#ifdef CONFIG_NUMA
put_page(new_page);
#endif
