From: Greg Kroah-Hartman Date: Sat, 3 Dec 2016 08:53:28 +0000 (+0100) Subject: 4.8-stable patches X-Git-Tag: v4.8.13~11 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f3269766fa7541968daa58e74a13709046ab6f78;p=thirdparty%2Fkernel%2Fstable-queue.git 4.8-stable patches added patches: rcu-fix-soft-lockup-for-rcu_nocb_kthread.patch --- diff --git a/queue-4.8/rcu-fix-soft-lockup-for-rcu_nocb_kthread.patch b/queue-4.8/rcu-fix-soft-lockup-for-rcu_nocb_kthread.patch new file mode 100644 index 00000000000..5e55f2f4613 --- /dev/null +++ b/queue-4.8/rcu-fix-soft-lockup-for-rcu_nocb_kthread.patch @@ -0,0 +1,88 @@ +From bedc1969150d480c462cdac320fa944b694a7162 Mon Sep 17 00:00:00 2001 +From: Ding Tianhong +Date: Wed, 15 Jun 2016 15:27:36 +0800 +Subject: rcu: Fix soft lockup for rcu_nocb_kthread + +From: Ding Tianhong + +commit bedc1969150d480c462cdac320fa944b694a7162 upstream. + +Carrying out the following steps results in a softlockup in the +RCU callback-offload (rcuo) kthreads: + +1. Connect to ixgbevf, and set the speed to 10Gb/s. +2. Use ifconfig to bring the nic up and down repeatedly. + +[ 317.005148] IPv6: ADDRCONF(NETDEV_CHANGE): eth2: link becomes ready +[ 368.106005] BUG: soft lockup - CPU#1 stuck for 22s! [rcuos/1:15] +[ 368.106005] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 +[ 368.106005] task: ffff88057dd8a220 ti: ffff88057dd9c000 task.ti: ffff88057dd9c000 +[ 368.106005] RIP: 0010:[] [] fib_table_lookup+0x14/0x390 +[ 368.106005] RSP: 0018:ffff88061fc83ce8 EFLAGS: 00000286 +[ 368.106005] RAX: 0000000000000001 RBX: 00000000020155c0 RCX: 0000000000000001 +[ 368.106005] RDX: ffff88061fc83d50 RSI: ffff88061fc83d70 RDI: ffff880036d11a00 +[ 368.106005] RBP: ffff88061fc83d08 R08: 0000000000000001 R09: 0000000000000000 +[ 368.106005] R10: ffff880036d11a00 R11: ffffffff819e0900 R12: ffff88061fc83c58 +[ 368.106005] R13: ffffffff816154dd R14: ffff88061fc83d08 R15: 00000000020155c0 +[ 368.106005] FS: 0000000000000000(0000) GS:ffff88061fc80000(0000) knlGS:0000000000000000 +[ 368.106005] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 +[ 368.106005] CR2: 00007f8c2aee9c40 CR3: 000000057b222000 CR4: 00000000000407e0 +[ 368.106005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 +[ 368.106005] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 +[ 368.106005] Stack: +[ 368.106005] 00000000010000c0 ffff88057b766000 ffff8802e380b000 ffff88057af03e00 +[ 368.106005] ffff88061fc83dc0 ffffffff815349a6 ffff88061fc83d40 ffffffff814ee146 +[ 368.106005] ffff8802e380af00 00000000e380af00 ffffffff819e0900 020155c0010000c0 +[ 368.106005] Call Trace: +[ 368.106005] +[ 368.106005] +[ 368.106005] [] ip_route_input_noref+0x516/0xbd0 +[ 368.106005] [] ? skb_release_data+0xd6/0x110 +[ 368.106005] [] ? kfree_skb+0x3a/0xa0 +[ 368.106005] [] ip_rcv_finish+0x29f/0x350 +[ 368.106005] [] ip_rcv+0x234/0x380 +[ 368.106005] [] __netif_receive_skb_core+0x676/0x870 +[ 368.106005] [] __netif_receive_skb+0x18/0x60 +[ 368.106005] [] process_backlog+0xae/0x180 +[ 368.106005] [] net_rx_action+0x152/0x240 +[ 368.106005] [] __do_softirq+0xef/0x280 +[ 368.106005] [] call_softirq+0x1c/0x30 +[ 368.106005] +[ 368.106005] +[ 368.106005] [] do_softirq+0x65/0xa0 +[ 368.106005] [] local_bh_enable+0x94/0xa0 +[ 368.106005] [] rcu_nocb_kthread+0x232/0x370 +[ 368.106005] [] ? wake_up_bit+0x30/0x30 +[ 368.106005] [] ? rcu_start_gp+0x40/0x40 +[ 368.106005] [] kthread+0xcf/0xe0 +[ 368.106005] [] ? kthread_create_on_node+0x140/0x140 +[ 368.106005] [] ret_from_fork+0x58/0x90 +[ 368.106005] [] ? kthread_create_on_node+0x140/0x140 + +==================================cut here============================== + +It turns out that the rcuos callback-offload kthread is busy processing +a very large quantity of RCU callbacks, and it is not reliquishing the +CPU while doing so. This commit therefore adds an cond_resched_rcu_qs() +within the loop to allow other tasks to run. + +Signed-off-by: Ding Tianhong +[ paulmck: Substituted cond_resched_rcu_qs for cond_resched. ] +Signed-off-by: Paul E. McKenney +Cc: Dhaval Giani +Signed-off-by: Greg Kroah-Hartman + +--- + kernel/rcu/tree_plugin.h | 1 + + 1 file changed, 1 insertion(+) + +--- a/kernel/rcu/tree_plugin.h ++++ b/kernel/rcu/tree_plugin.h +@@ -2173,6 +2173,7 @@ static int rcu_nocb_kthread(void *arg) + cl++; + c++; + local_bh_enable(); ++ cond_resched_rcu_qs(); + list = next; + } + trace_rcu_batch_end(rdp->rsp->name, c, !!list, 0, 0, 1); diff --git a/queue-4.8/series b/queue-4.8/series index 96ee2d07ded..c0dbb501dc6 100644 --- a/queue-4.8/series +++ b/queue-4.8/series @@ -11,3 +11,4 @@ mm-fix-false-positive-warn_on-in-truncate-invalidate-for-hugetlb.patch ovl-fix-d_real-for-stacked-fs.patch input-change-key_data-from-0x275-to-0x277.patch input-psmouse-disable-automatic-probing-of-byd-touchpads.patch +rcu-fix-soft-lockup-for-rcu_nocb_kthread.patch