Re: [PATCH v2 5/6] locking/lockdep: Decrement irq context counters when removing lock chain

From: Waiman Long
Date: Tue Jan 14 2020 - 10:04:34 EST


On 1/14/20 4:53 AM, Peter Zijlstra wrote:
> On Mon, Dec 16, 2019 at 10:15:16AM -0500, Waiman Long wrote:
>> There are currently three counters to track the irq context of a lock
>> chain - nr_hardirq_chains, nr_softirq_chains and nr_process_chains.
>> They are incremented when a new lock chain is added, but they are
>> not decremented when a lock chain is removed. That causes some of the
>> statistic counts reported by /proc/lockdep_stats to be incorrect.
>>
>> Fix that by decrementing the right counter when a lock chain is removed.
>>
>> Fixes: a0b0fd53e1e6 ("locking/lockdep: Free lock classes that are no longer in use")
>> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
> Fixes go at the start of a series, because if the depend on prior
> patches (as this one does) we cannot apply them.
>
Will put it at the front in the next version.

Cheers,
Longman