Re: [PATCH v2] don't forget to call pd_online_fn when activate policy

From: Jens Axboe
Date: Fri Mar 10 2017 - 23:03:38 EST



> On Mar 10, 2017, at 8:46 PM, zhouchengming <zhouchengming1@xxxxxxxxxx> wrote:
>
>> On 2017/3/10 23:12, Jens Axboe wrote:
>>> On 03/08/2017 07:20 PM, Zhou Chengming wrote:
>>> When we activate policy on the request_queue, we will create policy_date
>>> for all the existing blkgs of the request_queue, so we should call
>>> pd_init_fn() and pd_online_fn() on these newly created policy_data.
>>>
>>> Signed-off-by: Zhou Chengming<zhouchengming1@xxxxxxxxxx>
>>> ---
>>> block/blk-cgroup.c | 6 ++++++
>>> 1 file changed, 6 insertions(+)
>>>
>>> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
>>> index 8ba0af7..0dd9e76 100644
>>> --- a/block/blk-cgroup.c
>>> +++ b/block/blk-cgroup.c
>>> @@ -1254,6 +1254,12 @@ int blkcg_activate_policy(struct request_queue *q,
>>> pd->plid = pol->plid;
>>> if (pol->pd_init_fn)
>>> pol->pd_init_fn(pd);
>>> +
>>> + if (pol->pd_online_fn) {
>>> + spin_lock(blkg->blkcg->lock);
>>> + pol->pd_online_fn(pd);
>>> + spin_unlock(blkg->blkcg->lock);
>>> + }
>>
>> You didn't even compile this, did you?
>>
>
> Sorry for my carelessness. It's a very minor change, so I didn't compile...
> I will send a patch-v3 that I have compiled. Sorry again..

I don't care how trivial it seems. You always ALWAYS compile and test. Always. Don't ever send untested patches again, and not even compiling is unforgivable.