I get this on shutdown (after "Power Off" ironically).
2.6.5-rc3-mjb2.
Badness in find_busiest_group at kernel/sched.c:1425
Call Trace:
[<c0117c84>] find_busiest_group+0x64/0x22c
[<c0118091>] load_balance_newidle+0x21/0x6c
[<c0118c77>] schedule+0x273/0x644
[<c011e9c5>] exit_notify+0x609/0x64c
[<c011ed22>] do_exit+0x31a/0x32c
[<c0128c7a>] sys_reboot+0x1f2/0x2f8
[<c0116f50>] wake_up_state+0xc/0x10
[<c0125c37>] kill_proc_info+0x37/0x4c
[<c0125d30>] kill_something_info+0xe4/0xec
[<c01279e8>] sys_kill+0x54/0x5c
[<c014caa3>] filp_open+0x3b/0x5c
[<c014ce79>] sys_open+0x59/0x74
[<c01075f9>] error_code+0x2d/0x38
[<c0106b8f>] syscall_call+0x7/0xb
Look familar?
> I get this on shutdown (after "Power Off" ironically).
> 2.6.5-rc3-mjb2.
>
> Badness in find_busiest_group at kernel/sched.c:1425
> Call Trace:
> [<c0117c84>] find_busiest_group+0x64/0x22c
> [<c0118091>] load_balance_newidle+0x21/0x6c
> [<c0118c77>] schedule+0x273/0x644
> [<c011e9c5>] exit_notify+0x609/0x64c
> [<c011ed22>] do_exit+0x31a/0x32c
> [<c0128c7a>] sys_reboot+0x1f2/0x2f8
> [<c0116f50>] wake_up_state+0xc/0x10
> [<c0125c37>] kill_proc_info+0x37/0x4c
> [<c0125d30>] kill_something_info+0xe4/0xec
> [<c01279e8>] sys_kill+0x54/0x5c
> [<c014caa3>] filp_open+0x3b/0x5c
> [<c014ce79>] sys_open+0x59/0x74
> [<c01075f9>] error_code+0x2d/0x38
> [<c0106b8f>] syscall_call+0x7/0xb
>
> Look familar?
Dunno why the numbers are different, but it's now 1738 in 2.6.5-mjb1 ...
I wouldn't have thought we'd inserted that much since then. anyway, it's
this:
/* Tally up the load of all CPUs in the group */
cpus_and(tmp, group->cpumask, cpu_online_map);
WARN_ON(cpus_empty(tmp));
in find_busiest_group. Which makes sense I guess, but is very ugly.
M.
Martin J. Bligh wrote:
>>I get this on shutdown (after "Power Off" ironically).
>>2.6.5-rc3-mjb2.
>>
>>Badness in find_busiest_group at kernel/sched.c:1425
>>Call Trace:
>> [<c0117c84>] find_busiest_group+0x64/0x22c
>> [<c0118091>] load_balance_newidle+0x21/0x6c
>> [<c0118c77>] schedule+0x273/0x644
>> [<c011e9c5>] exit_notify+0x609/0x64c
>> [<c011ed22>] do_exit+0x31a/0x32c
>> [<c0128c7a>] sys_reboot+0x1f2/0x2f8
>> [<c0116f50>] wake_up_state+0xc/0x10
>> [<c0125c37>] kill_proc_info+0x37/0x4c
>> [<c0125d30>] kill_something_info+0xe4/0xec
>> [<c01279e8>] sys_kill+0x54/0x5c
>> [<c014caa3>] filp_open+0x3b/0x5c
>> [<c014ce79>] sys_open+0x59/0x74
>> [<c01075f9>] error_code+0x2d/0x38
>> [<c0106b8f>] syscall_call+0x7/0xb
>>
>>Look familar?
>>
>
>Dunno why the numbers are different, but it's now 1738 in 2.6.5-mjb1 ...
>I wouldn't have thought we'd inserted that much since then. anyway, it's
>this:
>
> /* Tally up the load of all CPUs in the group */
> cpus_and(tmp, group->cpumask, cpu_online_map);
> WARN_ON(cpus_empty(tmp));
>
>in find_busiest_group. Which makes sense I guess, but is very ugly.
>
>
I think the WARN_ON can go. You have to make sure the for_each_cpu
loop doesn't get to run it though. It shouldn't be in the latest -mm
kernels, is it?
It is normal to have an entire group offline with CPU hotplug.
> I think the WARN_ON can go. You have to make sure the for_each_cpu
> loop doesn't get to run it though. It shouldn't be in the latest -mm
> kernels, is it?
OK, I'll figure it out. I don't like the latest code, so don't really want
to "upgrade" though.
> It is normal to have an entire group offline with CPU hotplug.
Only if we can't figure out how to hotplug groups as well, which would
be a much cleaner way of doing it.
M.
Martin J. Bligh wrote:
>>I think the WARN_ON can go. You have to make sure the for_each_cpu
>>loop doesn't get to run it though. It shouldn't be in the latest -mm
>>kernels, is it?
>
>
> OK, I'll figure it out. I don't like the latest code, so don't really want
> to "upgrade" though.
>
Oh? Anything specific?
>
>>It is normal to have an entire group offline with CPU hotplug.
>
>
> Only if we can't figure out how to hotplug groups as well, which would
> be a much cleaner way of doing it.
>
I think we'll soon want to add a sched domain setup callback
for hotplug that can take care of these things as required.
But for now, the current situation should be OK.
>> OK, I'll figure it out. I don't like the latest code, so don't really want
>> to "upgrade" though.
>
> Oh? Anything specific?
balance_on_clone, mostly.
M.
Martin J. Bligh wrote:
>>>OK, I'll figure it out. I don't like the latest code, so don't really want
>>>to "upgrade" though.
>>
>>Oh? Anything specific?
>
>
> balance_on_clone, mostly.
>
Oh, that is removed until more testing/tuning is done.
So far I haven't seen a benchmark with more than a few %
improvement. I thought I was going to be flooded with them
from the HPC guys after the last thread on the subject...