On 2021/5/28 15:01, Peter Zijlstra wrote:

On Fri, May 28, 2021 at 03:58:42AM +0000, liweihang wrote:

quoted

Peter, could you please explain why you said "add_return and sub_return are
horrible interface for refcount"?

What would you need them for? The only special value is 0. Once you hit
0 the object is dead and you cannot revive.

quoted

If I look at drivers/infiniband/sw/rdmavt/mcast.c, which seems to be the

relevant file, the thing that's called ->refcount is not in fact a
reference count.

I see, thank you.

refcount_t is not suitable for the current logic, so let's leave it as it is. I
will drop this patch from the series.

Weihang