Messages in this thread Patch in this message | | | Date | Wed, 9 Feb 2011 16:23:24 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | [PATCH][BUGFIX] memcg: fix leak of accounting at failure path of hugepage collapsing. |
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There was a big bug. Anyway, thank you for adding new bad_page for memcg. ==
mem_cgroup_uncharge_page() should be called in all failure case 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> --- mm/huge_memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
Index: mmotm-0204/mm/huge_memory.c =================================================================== --- mmotm-0204.orig/mm/huge_memory.c +++ mmotm-0204/mm/huge_memory.c @@ -1852,7 +1852,6 @@ static void collapse_huge_page(struct mm 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 @@ out_up_write: return; out: + mem_cgroup_uncharge_page(new_page); #ifdef CONFIG_NUMA put_page(new_page); #endif
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