On Wed, Sep 17, 2014 at 03:17:52PM +0800, Wanpeng Li 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
>
> This bug can be triggered by hot add and remove large number of xen
> domain0's vcpus repeatedly.
>
> 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.
>
> Reviewed-by: Toshi Kani <toshi.k...@hp.com>
> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasu...@jp.fujitsu.com>
> Tested-by: Linn Crosetto <l...@hp.com>
> Signed-off-by: Wanpeng Li <wanpeng...@linux.intel.com>
Reviewed-by: Borislav Petkov <b...@suse.de>
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
--
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/
