From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net (unknown [184.105.139.130]) by lists.ozlabs.org (Postfix) with ESMTP id 3wGTSw0JrkzDqGr for ; Mon, 1 May 2017 12:51:10 +1000 (AEST) Date: Sun, 30 Apr 2017 22:50:56 -0400 (EDT) Message-Id: <20170430.225056.522551868142970014.davem@davemloft.net> To: swood@redhat.com Cc: Yuval.Mintz@cavium.com, ariel.elior@cavium.com, everest-linux-l2@cavium.com, netdev@vger.kernel.org, edumazet@google.com, mschmidt@redhat.com, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH net] bnx2x: Align RX buffers From: David Miller In-Reply-To: <20170429001741.14563-1-swood@redhat.com> References: <20170429001741.14563-1-swood@redhat.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Scott Wood Date: Fri, 28 Apr 2017 19:17:41 -0500 > The bnx2x driver is not providing proper alignment on the receive buffers it > passes to build_skb(), causing skb_shared_info to be misaligned. > skb_shared_info contains an atomic, and while PPC normally supports > unaligned accesses, it does not support unaligned atomics. > > Aligning the size of rx buffers will ensure that page_frag_alloc() returns > aligned addresses. > > This can be reproduced on PPC by setting the network MTU to 1450 (or other > non-multiple-of-4) and then generating sufficient inbound network traffic > (one or two large "wget"s usually does it), producing the following oops: ... > Fixes: d46d132cc021 ("bnx2x: use netdev_alloc_frag()") > Signed-off-by: Scott Wood Applied, thanks.