Hi,
On Wednesday 07 January 2015 03:07 PM, Alexey Kardashevskiy wrote: > Hi! > > "ppc64_cpu --smt=off" produces multiple error on the latest upstream kernel > (sha1 bdec419): > > NMI watchdog: BUG: soft lockup - CPU#20 stuck for 23s! [swapper/20:0] > > or > > INFO: rcu_sched detected stalls on CPUs/tasks: { 2 7 8 9 10 11 12 13 14 15 > 16 17 18 19 20 21 22 23 2 > 4 25 26 27 28 29 30 31} (detected by 6, t=2102 jiffies, g=1617, c=1616, > q=1441) > > and many others, all about lockups > > I did bisecting and found out that reverting these helps: > > 77b54e9f213f76a23736940cf94bcd765fc00f40 powernv/powerpc: Add winkle > support for offline cpus > 7cba160ad789a3ad7e68b92bf20eaad6ed171f80 powernv/cpuidle: Redesign idle > states management > 8eb8ac89a364305d05ad16be983b7890eb462cc3 powerpc/powernv: Enable Offline > CPUs to enter deep idle states > > btw reverting just two of them produces a compile error. > > It is pseries_le_defconfig, POWER8 machine: > timebase : 512000000 > platform : PowerNV > model : palmetto > machine : PowerNV palmetto > firmware : OPAL v3 > > > Please help to fix it. Thanks. > > Upon investigation, we figured that the cpu is stuck in cpu_idle_poll loop in kernel/sched/idle.c leading us to believe the bug is in timer offload framework which fastsleep uses. Preeti and I are working on a fix. We'll post it out as soon as possible. Thanks, Shreyas _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev