On 31/07/2019 16:33, Leon Romanovsky wrote:
> On Wed, Jul 31, 2019 at 03:56:55PM +0300, Gal Pressman wrote:
>> On 31/07/2019 14:46, Leon Romanovsky wrote:
>>> On Wed, Jul 31, 2019 at 01:51:05PM +0300, Gal Pressman wrote:
>>>> On 31/07/2019 10:41, Leon Romanovsky wrote:
>>>>> On Wed, Jul 31, 2019 at 10:22:42AM +0300, Gal Pressman wrote:
>>>>>> On 30/07/2019 18:41, Leon Romanovsky wrote:
>>>>>>> On Tue, Jul 30, 2019 at 06:18:33PM +0300, Gal Pressman wrote:
>>>>>>>> Add ratelimited helpers to the ibdev_* printk functions.
>>>>>>>> Implementation inspired by counterpart dev_*_ratelimited functions.
>>>>>>>>
>>>>>>>> Signed-off-by: Gal Pressman <galpress@xxxxxxxxxx>
>>>>>>>> ---
>>>>>>>> include/rdma/ib_verbs.h | 51 +++++++++++++++++++++++++++++++++++++++++
>>>>>>>> 1 file changed, 51 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
>>>>>>>> index c5f8a9f17063..356e6a105366 100644
>>>>>>>> --- a/include/rdma/ib_verbs.h
>>>>>>>> +++ b/include/rdma/ib_verbs.h
>>>>>>>> @@ -107,6 +107,57 @@ static inline
>>>>>>>> void ibdev_dbg(const struct ib_device *ibdev, const char *format, ...) {}
>>>>>>>> #endif
>>>>>>>>
>>>>>>>> +#define ibdev_level_ratelimited(ibdev_level, ibdev, fmt, ...) \
>>>>>>>> +do { \
>>>>>>>> + static DEFINE_RATELIMIT_STATE(_rs, \
>>>>>>>> + DEFAULT_RATELIMIT_INTERVAL, \
>>>>>>>> + DEFAULT_RATELIMIT_BURST); \
>>>>>>>> + if (__ratelimit(&_rs)) \
>>>>>>>> + ibdev_level(ibdev, fmt, ##__VA_ARGS__); \
>>>>>>>> +} while (0)
>>>>>>>> +
>>>>>>>> +#define ibdev_emerg_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_emerg, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +#define ibdev_alert_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_alert, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +#define ibdev_crit_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_crit, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +#define ibdev_err_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_err, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +#define ibdev_warn_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_warn, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +#define ibdev_notice_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_notice, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +#define ibdev_info_ratelimited(ibdev, fmt, ...) \
>>>>>>>> + ibdev_level_ratelimited(ibdev_info, ibdev, fmt, ##__VA_ARGS__)
>>>>>>>> +
>>>>>>>> +#if defined(CONFIG_DYNAMIC_DEBUG)
>>>>>>>> +/* descriptor check is first to prevent flooding with "callbacks suppressed" */
>>>>>>>> +#define ibdev_dbg_ratelimited(ibdev, fmt, ...) \
>>>>>>>> +do { \
>>>>>>>> + static DEFINE_RATELIMIT_STATE(_rs, \
>>>>>>>> + DEFAULT_RATELIMIT_INTERVAL, \
>>>>>>>> + DEFAULT_RATELIMIT_BURST); \
>>>>>>>> + DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt); \
>>>>>>>> + if (DYNAMIC_DEBUG_BRANCH(descriptor) && __ratelimit(&_rs)) \
>>>>>>>> + __dynamic_ibdev_dbg(&descriptor, ibdev, fmt, \
>>>>>>>> + ##__VA_ARGS__); \
>>>>>>>> +} while (0)
>>>>>>>> +#elif defined(DEBUG)
>>>>>>>
>>>>>>> When will you see this CONFIG_DEBUG set? I suspect only in private
>>>>>>> out-of-tree builds which we are not really care. Also I can't imagine
>>>>>>> system with this CONFIG_DEBUG and without CONFIG_DYNAMIC_DEBUG.
>>>>>>
>>>>>> This is the common way to handle debug prints, see:
>>>>>> https://elixir.bootlin.com/linux/v5.2.1/source/include/linux/printk.h#L331
>>>>>> https://elixir.bootlin.com/linux/v5.2.1/source/include/linux/device.h#L1493
>>>>>> https://elixir.bootlin.com/linux/v5.2.1/source/include/linux/netdevice.h#L4743
>>>>>> https://elixir.bootlin.com/linux/v5.2.1/source/include/linux/net.h#L266
>>>>>
>>>>> I'm more interested to know the real usage of this copy/paste and
>>>>> understand if it makes sense for drivers/infiniband/* or not.
>>>>>
>>>>> Not everything in netdev is great and worth to borrow.
>>>>
>>>> DEBUG exists since the first commit in the tree, and is used in various parts of
>>>> the kernel (mlx5 as well). Do you think it should be removed from the kernel?
>>>
>>> It is gradually removed when it is spotted, I'll send a patch for mlx5 now.
>>
>> Was there an on-list discussion regarding removal of DEBUG usage? Can you please
>> share a link?
>
> Sorry, but no, I didn't know that I need to save all discussions I see
> in the mailing lists.
Trying to understand whether "It is gradually removed when it is spotted" is a
well known guideline by the community, should checkpatch produce a warning for this?
>
>> If so, I agree the DEBUG part should be removed.
>>
>>>
>>>>
>>>> Regarding combination of both, I don't think DEBUG is related to
>>>> CONFIG_DYNAMIC_DEBUG. DEBUG is a generic debug flag (not necessarily to prints)
>>>> while CONFIG_DYNAMIC_DEBUG is specific to the dynamic debug prints infrastructure.
>>>
>>> I know exactly what DEBUG and CONFIG_DYNAMIC_DEBUG mean, but I'm
>>> asking YOU to provide us real and in-tree scenario where DEBUG will
>>> exists and CONFIG_DYNAMIC_DEBUG won't.
>>
>> What's any of this has to do with in-tree? This code and defines are part of the
>> tree.
>>
>> The use case doesn't matter, it's a valid permutation. Is there anything that
>> stops a user from building the kernel this way?
>
> Like everything else, nothing stops from you to do any modifications to
> the source code, before you will build. We are talking about in-tree
> builds and distro kernels.
Last I checked turning on DEBUG doesn't require source code changes?
