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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <ada4ozhss2w.fsf@cisco.com>
Date:	Thu, 29 Jan 2009 13:47:03 -0800
From:	Roland Dreier <rdreier@...co.com>
To:	Olaf Kirch <okir@...e.de>
Cc:	Andy Grover <andy.grover@...cle.com>, rds-devel@....oracle.com,
	general@...ts.openfabrics.org, netdev@...r.kernel.org
Subject: Re: [PATCH 17/21] RDS/IB: Receive datagrams via IB

 > > > 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.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html