From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH 1/4] RDMA/bnxt_re: Add memory barriers when processing CQ/EQ entries Date: Mon, 6 Nov 2017 10:19:25 -0700 Message-ID: <20171106171925.GB18802@ziepe.ca> References: <1509984452-18336-1-git-send-email-selvin.xavier@broadcom.com> <1509984452-18336-2-git-send-email-selvin.xavier@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1509984452-18336-2-git-send-email-selvin.xavier-dY08KVG/lbpWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Selvin Xavier Cc: dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Somnath Kotur List-Id: linux-rdma@vger.kernel.org On Mon, Nov 06, 2017 at 08:07:29AM -0800, Selvin Xavier wrote: > From: Somnath Kotur > > The code determines if the next ring entry is valid before proceeding > further to read the rest of the entry. The CPU can re-order and read > the rest of the entry first, possibly reading a stale entry, if DMA > of a new entry happens right after reading it. Please make sure the bnxt user space stuff in rdma-core does not have the same problem... Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html