Re: [PATCH v7 4/5] docs: counter: Document character device interface

From: David Lechner
Date: Wed Dec 30 2020 - 13:21:45 EST


On 12/25/20 6:15 PM, William Breathitt Gray wrote:

+Userspace
+---------
+Userspace applications can configure Counter events via ioctl operations
+on the Counter character device node. There following ioctl codes are
+supported and provided by the `linux/counter.h` userspace header file:
+
+* COUNTER_CLEAR_WATCHES_IOCTL:
+ Clear all Counter watches from all events
+
+* COUNTER_ADD_WATCH_IOCTL:
+ Add a Counter watch for the specified event
+
+* COUNTER_LOAD_WATCHES_IOCTL:
+ Activates the Counter watches added earlier

Would it make more sense to call the last and first ones
COUNTER_ENABLE_EVENTS_IOCTL and COUNTER_DISABLE_EVENTS_IOCTL?
In any case, more explanation would be helpful.

* COUNTER_ADD_WATCH_IOCTL:
Queues a Counter watch for the specified event. The queued watches
will not be applied until COUNTER_ENABLE_EVENTS_IOCTL is called.

* COUNTER_ENABLE_EVENTS_IOCTL:
Enables monitoring the events specified by the Counter watches that were
queued by COUNTER_ADD_WATCH_IOCTL. If events are already enabled, the new
set of watches replaces the old one. Calling this ioctl also has the
effect of clearing the queue of watches added by COUNTER_ADD_WATCH_IOCTL.

* COUNTER_DISABLE_EVENTS_IOCTL:
Stops monitoring the previously enabled events.

+
+To configure events to gather Counter data, users first populate a
+`struct counter_watch` with the relevant event id, event channel id, and
+the information for the desired Counter component from which to read,
+and then pass it via the `COUNTER_ADD_WATCH_IOCTL` ioctl command.

for restructured text, two backticks are needed for ``code`` formatting