From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: mlxsw and rtnl lock Date: Mon, 28 Aug 2017 12:00:39 -0600 Message-ID: References: <20170826170418.GA22324@shredder> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Jiri Pirko , "netdev@vger.kernel.org" , mlxsw@mellanox.com To: Ido Schimmel Return-path: Received: from mail-pf0-f178.google.com ([209.85.192.178]:34443 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750866AbdH1SAl (ORCPT ); Mon, 28 Aug 2017 14:00:41 -0400 Received: by mail-pf0-f178.google.com with SMTP id h75so3313983pfh.1 for ; Mon, 28 Aug 2017 11:00:41 -0700 (PDT) In-Reply-To: <20170826170418.GA22324@shredder> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 8/26/17 11:04 AM, Ido Schimmel wrote: > Regarding the silent abort, that's intentional. You can look at the same > code in v4.9 - when the chain was still blocking - and you'll see that > we didn't propagate the error even then. This was discussed in the past > and the conclusion was that user doesn't expect to operation to fail. If > hardware resources are exceeded, we let the kernel take care of the > forwarding instead. > In addition to Roopa's comments... The silent abort is not a good user experience. Right now it's add a network address or route, cross fingers and hope it does not overflow some limit (nexthop, ecmp, neighbor, prefix, etc) that triggers the offload abort. The mlxsw driver queries for some limits (e.g., max rifs) but I don't see any query related to current usage, and there is no API to pass any of that data to user space so user space has no programmatic way to handle this. I realize you are aware of this limitation. The point is to emphasize the need to resolve this.