On Wed, 2018-11-28 at 11:50 -0700, Jens Axboe wrote:

On 11/28/18 2:33 AM, Benny Halevy wrote:

quoted

quoted

I don't see how we can get there with it being larger than already,
that would be a big bug if we fill more events than userspace asked
for.

Currently we indeed can't, but if the code changes in the future and
we do, this will reduce the damage - hence being safer (and it costs
nothing in terms of performance).

The thing is, if we're ever over max, we have potentially corrupted user
space memory by copying back too many events. So if anything, it should
be a BUG() condition, not just a check.

Agreed.