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?
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?
