Re: [RFC PATCH 1/2] lib: debugobjects: export max loops counter

From: Waiman Long
Date: Mon Nov 27 2017 - 13:08:37 EST


On 11/27/2017 12:53 PM, Yang Shi wrote:
> Hi Waiman & tglx,
>
> I'm not sure who is the maintainer for lib/debugobjects.c now, I'm
> supposed tglx still is, however, get_maintainer.pl told me Waiman is
> the most active developer of this, so added Waiman in this loop in
> case he didn't see the patches on LKML.
>
> Thanks,
> Yang
>
> On 11/17/17 11:43 AM, Yang Shi wrote:
>> Currently max chain counter is exported to sysfs, it just record the

It is the debugfs, which is different from sysfs.

>> counter of inner loop, however, there might be significant iterations of
>> external loop then it may take significant amount of time to finish all
>> of the checks. This may cuase lockup on !CONFIG_PREEMPT kernel build
>> occasionally.
>>
>> Record the counter of the max loops then export to sysfs so that the
>> user can be aware of the real overhead.
>>
>> Then the output of /sys/kernel/debug/debug_objects/stats looks like:
>>
>> max_chain :121
>> max_loops :543267
>> warnings :0
>> fixups :0
>> pool_free :1764
>> pool_min_free :341
>> pool_used :86438
>> pool_max_used :268887
>> objs_allocated:6068254
>> objs_freed :5981076
>>
>> Signed-off-by: Yang Shi <yang.s@xxxxxxxxxxxxxxx>

I have no objection to adding one more tracking count.

Cheers,
Longman