[rds-devel] [PATCH 17/21] RDS/IB: Receive datagrams via IB

[Roland Dreier]

 > > > This is racy.  You check if you're at the limit, do the allocation, and
 > > > then increment the atomic rds_ib_allocation count.  So many threads can
 > > > pass the atomic_read() test and then take you over the limit.  If you
 > > > want to make it safe then you could do atomic_inc_return() and check if
 > > > that took you over the limit.
 > >
 > > Woah, yup, thanks.
 > 
 > The refill code used to be single-threaded; and I think it still is. So
 > this can't race I think

So you don't need the atomic op at all?

 - R.