Re: [PATCH 10/18] fsinfo: Provide notification overrun handling support [ver #21]

On Tue, 2020-08-04 at 15:56 +0200, Miklos Szeredi wrote:

On Mon, Aug 03, 2020 at 02:37:50PM +0100, David Howells wrote:

quoted

Provide support for the handling of an overrun in a watch
queue.  In the
event that an overrun occurs, the watcher needs to be able to find
out what
it was that they missed.  To this end, previous patches added event
counters to struct mount.

So this is optimizing the buffer overrun case?

Shoun't we just make sure that the likelyhood of overruns is low and
if it
happens, just reinitialize everthing from scratch (shouldn't be
*that*
expensive).

But maybe not possible if you are using notifications for tracking
state in user space, you need to know when the thing you have needs
to be synced because you missed something and it's during the
notification processing you actually have the object that may need
to be refreshed.

Trying to find out what was missed seems like just adding complexity
for no good
reason.