Messages in this thread | | | Date | Sat, 11 Nov 2017 20:38:32 +0100 | From | Bruno Prémont <> | Subject | RCU stall/SOFT-Lockup on 4.11.3/4.13.11 after multiple days uptime |
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Hi,
On a single-CPU KVM-based virtual machine I'm suffering from RCU stall and soft-lockup. 4.10.x kernels run fine (4.10.12) but starting with 4.11.x (4.11.3, 4.13.11) I'm getting system freezes for no apparent reason.
All info I have is following console dump (from 4.13.11): [526415.290012] INFO: rcu_sched self-detected stall on CPU [526415.290012] o0-...: (745847 ticks this GP) idle=ba2/2/0 softirq=37393463/37393463 fqs=0 [526415.290012] o (t=745854 jiffies g=23779976 c=23779975 q=32) [526415.290012] rcu_sched kthread starved for 745854 jiffies! g23779976 c23779975 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 [526440.020015] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0] [526468.020005] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0] [526478.320009] INFO: rcu_sched self-detected stall on CPU [526478.320009] o0-...: (752143 ticks this GP) idle=ba2/2/0 softirq=37393463/37393463 fqs=0 [526478.320009] o (t=752157 jiffies g=23779976 c=23779975 q=32) [526478.320009] rcu_sched kthread starved for 752157 jiffies! g23779976 c23779975 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 [526504.020016] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0] [526532.020007] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0] ...
Attached is kernel config (4.13.11).
The output obtained with 4.11.3 was: [ 280.680010] INFO: rcu_sched self-detected stall on CPU [ 280.680021] o0-...: (27312 ticks this GP) dile=b11/2/0 softirq=6119/6119 fqs=0 [ 280.680021] o (t=27312 jiffies g=441 c=440 q=0) [ 280.680021] rcu_sched_kthread starved for 27312 jiffies! g441 c440 f0x0 RCU_GP_WAIT_FQS(3) ->state=0x0 ...
As it's a remote VM for which I don't have access to the host I have little options for further digging (can't trigger sysrq's).
Same kernel (4.13.11) seems to be running just fine on another KVM-base VM that has two CPUs.
Does it ring a bell or is there some info that might be of any use, assuming I can obtain it?
Bruno[unhandled content-type:application/octet-stream] | |