[Intel-wired-lan] [PATCH 3/4] devlink: add support for triggering snapshots from userspace

[Jiri Pirko]

Thu, Jan 09, 2020 at 02:08:18AM CET, jacob.e.keller at intel.com wrote:
>Currently, devlink region snapshots are captured by the driver at some
>internal trigger. There is no standard method for userspace to request
>that a snapshot be created.
>
>For some use cases of regions, this is acceptable. The snapshots only
>make sense if taken in response to some internal driver event.
>
>However, regions could be used for other purposes. For example, a driver
>might export a region that represents the contents of some portion of
>the device flash. In this case, there is no event that triggers
>a snapshot. Instead, it makes sense for user space to request a snapshot
>in some manner.
>
>Currently, drivers must implement such a trigger through an out-of-band
>mechanism. The netdevsim driver does this through a debugfs file.
>
>Create a standard interface for requesting snapshots via a new devlink
>command: DEVLINK_CMG_REGION_TRIGGER_SNAPSHOT.
>
>At region creation time, drivers may optionally define
>a trigger_snapshot function callback. If not defined, the
>DEVLINK_CMD_REGION_TRIGGER_SNAPSHOT will simply report EOPNOTSUPP.

Similar mechanism is already implemented for health reporters. Why that
wouln't work for you?