On Thu, Sep 04, 2014 at 02:40:07PM +0900, Yasuaki Ishimatsu wrote: >(2014/09/04 14:20), Ingo Molnar wrote: >> >>* Wanpeng Li <wanpeng...@linux.intel.com> wrote: >> >>>BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 >>>IP: [..] find_busiest_group >>>PGD 5a9d5067 PUD 13067 PMD 0 >>>Oops: 0000 [#3] SMP >>>[...] >>>Call Trace: >>>load_balance >>>? _raw_spin_unlock_irqrestore >>>idle_balance >>>__schedule >>>schedule >>>schedule_timeout >>>? lock_timer_base >>>schedule_timeout_uninterruptible >>>msleep >>>lock_device_hotplug_sysfs >>>online_store >>>dev_attr_store >>>sysfs_write_file >>>vfs_write >>>SyS_write >>>system_call_fastpath >>> >>>Last level cache shared map is built during cpu up and build sched domain >>>routine takes advantage of it to setup sched domain cpu topology, however, >>>llc shared map is unreleased during cpu disable which lead to invalid sched >>>domain cpu topology. This patch fix it by release llc shared map correctly >>>during cpu disable. >> >>Very little is said in this changelog about how the bug was >>found, how likely it is to occur for others, what systems are >>affected, etc. > >Hi Wanpeng,
Hi Yasuaki, > >In my understanding, the panic occurs by just onlining CPU as follows: >echo 1 > /sys/devices/system/cpu/cpuX/online > See my reply to Ingo. Regards, Wanpeng Li >So, how about add the information? > >Thanks, >Yasuaki Ishimatsu > > >> >>Thanks, >> >> Ingo >> > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
