From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753926AbdASRLk (ORCPT ); Thu, 19 Jan 2017 12:11:40 -0500 Received: from shards.monkeyblade.net ([184.105.139.130]:32966 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753174AbdASRLj (ORCPT ); Thu, 19 Jan 2017 12:11:39 -0500 Date: Thu, 19 Jan 2017 12:11:37 -0500 (EST) Message-Id: <20170119.121137.735637643552808729.davem@davemloft.net> To: vineethp@amazon.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] xen-netfront: Fix Rx stall during network stress and OOM From: David Miller In-Reply-To: <66b10c64-936a-8001-6855-2ff1ed626642@amazon.com> References: <1484771149-12699-1-git-send-email-vineethp@u480fcf3b67f557f68df1.ant.amazon.com> <66b10c64-936a-8001-6855-2ff1ed626642@amazon.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 19 Jan 2017 08:12:33 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Vineeth Remanan Pillai Date: Thu, 19 Jan 2017 08:35:39 -0800 > From: Vineeth Remanan Pillai > > During an OOM scenario, request slots could not be created as skb > allocation fails. So the netback cannot pass in packets and netfront > wrongly assumes that there is no more work to be done and it disables > polling. This causes Rx to stall. > > The issue is with the retry logic which schedules the timer if the > created slots are less than NET_RX_SLOTS_MIN. The count of new request > slots to be pushed are calculated as a difference between new req_prod > and rsp_cons which could be more than the actual slots, if there are > unconsumed responses. > > The fix is to calculate the count of newly created slots as the > difference between new req_prod and old req_prod. > > Signed-off-by: Vineeth Remanan Pillai > Reviewed-by: Juergen Gross > --- > Changes in v2: > - Removed the old implementation of enabling polling on > skb allocation error. > - Corrected the refill timer logic to schedule when newly > created slots since last push is less than NET_RX_SLOTS_MIN. Your postings aren't showing up on vger.kernel.org at all. Are you getting a bounce message back? I can only assume you are triggering one of the various content filters we have.