Subject: Re: [PATCH 17/21] RDS/IB: Receive datagrams via IB

From: Olaf Kirch <[email-masked]>
Date: Thu, 29 Jan 2009 22:02:28 +0100

On Thursday 29 January 2009 03:20:40 Andy Grover wrote:
> > 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

Olaf