On Wed, Nov 07, 2012 at 05:27:12PM +0800, Zhouping Liu wrote: > > Hello Mel, > > my 2 nodes machine hit a panic fault after applied the patch > set(based on kernel-3.7.0-rc4), please review it: > > <SNIP> Early initialisation problem by the looks of things. Try this please ---8<--- mm: numa: Check that preferred_node_policy is initialised Zhouping Liu reported the following [ 0.000000] ------------[ cut here ]------------ [ 0.000000] kernel BUG at mm/mempolicy.c:1785! [ 0.000000] invalid opcode: 0000 [#1] SMP [ 0.000000] Modules linked in: [ 0.000000] CPU 0 .... [ 0.000000] Call Trace: [ 0.000000] [<ffffffff81176966>] alloc_pages_current+0xa6/0x170 [ 0.000000] [<ffffffff81137a44>] __get_free_pages+0x14/0x50 [ 0.000000] [<ffffffff819efd9b>] kmem_cache_init+0x53/0x2d2 [ 0.000000] [<ffffffff819caa53>] start_kernel+0x1e0/0x3c7 Problem is that early in boot preferred_nod_policy and SLUB initialisation trips up. Check it is initialised. Signed-off-by: Mel Gorman <mgorman@xxxxxxx> --- mm/mempolicy.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 11d4b6b..8cfa6dc 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -129,6 +129,10 @@ static struct mempolicy *get_task_policy(struct task_struct *p) node = numa_node_id(); if (node != -1) pol = &preferred_node_policy[node]; + + /* preferred_node_policy is not initialised early in boot */ + if (!pol->mode) + pol = NULL; } return pol; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>