On Wed, Jul 31, 2019 at 05:19:41PM +0300, Gal Pressman wrote:
> 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?
I didn't see checks in checkpatch about tabs<->spaces mix either which you
pointed for hns guys.
>
> >
> >> 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?
Exciting, how did you enable DEBUG without recompiling source code?
Maybe you find a way to enable DEBUG on running kernel?
And how did it come that v5.3 kernel was compiled with DEBUG but
without DYNAMIC_DEBUG?
Thanks
