From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70CE7C43460 for ; Thu, 15 Apr 2021 14:02:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D94A611F1 for ; Thu, 15 Apr 2021 14:02:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230202AbhDOOCu (ORCPT ); Thu, 15 Apr 2021 10:02:50 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:60104 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230056AbhDOOCu (ORCPT ); Thu, 15 Apr 2021 10:02:50 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 13FDtThf032413; Thu, 15 Apr 2021 14:02:21 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : references : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2020-01-29; bh=UegrpDQcSmXaGPLm8m7uglZyqP+5mlbSvLnUGf3+TXI=; b=K4sMLzPs6+5CxX6a7R4XXMux+TFh5cNuSaNZpsUFXLamBbiGe/bl6aapL06vZo2QG/wM iyFLRsKBDyRsQ6CGlDBCSSq+j4DkaFTOePxi6qJ7nPlduIsG9Ig0qsMzMHnH2wH+J5hT ibI1FAV44odh2tr2S9Ul6n5udKSka0jVAKQfU/dSyEufJ3JPkUk8d7c56ZD1npCNEAIx KAStQVLjen+neo/6CXEaqj2jDx+yZEoJK/9CizX5LIhox+GMPXwox84+271f9eOo5p8p 1V5wdSCTyg6nNn+4by/ygguDN6i6TqErAW7xecJrS5GtyK7htFIbld0j5il80IKXzK/V Qg== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 37u4nnnwr7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Apr 2021 14:02:21 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 13FE1dVI187879; Thu, 15 Apr 2021 14:02:21 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 37unsvmw7b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 15 Apr 2021 14:02:21 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 13FE2K6w009438; Thu, 15 Apr 2021 14:02:20 GMT Received: from [10.175.182.99] (/10.175.182.99) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 15 Apr 2021 14:02:20 +0000 Subject: Re: [PATCH] net/mlx4: Treat VFs fair when handling comm_channel_events From: Hans Westgaard Ry To: linux-rdma@vger.kernel.org, Jason Gunthorpe , Doug Ledford Cc: Jack Morgenstein References: <1618487022-15770-1-git-send-email-hans.westgaard.ry@oracle.com> Message-ID: <655a2db9-e4a6-3dc1-62d3-50c09de9805b@oracle.com> Date: Thu, 15 Apr 2021 16:02:17 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <1618487022-15770-1-git-send-email-hans.westgaard.ry@oracle.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9955 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=999 adultscore=0 malwarescore=0 suspectscore=0 bulkscore=0 mlxscore=0 spamscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104150094 X-Proofpoint-ORIG-GUID: KFCyiOIXcSs5MneAMuIez-JAdKewxyBe X-Proofpoint-GUID: KFCyiOIXcSs5MneAMuIez-JAdKewxyBe X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=9955 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 phishscore=0 suspectscore=0 mlxlogscore=999 priorityscore=1501 clxscore=1011 lowpriorityscore=0 spamscore=0 impostorscore=0 bulkscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104150093 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 4/15/21 1:43 PM, Hans Westgaard Ry wrote: > Handling comm_channel_event in mlx4_master_comm_channel uses a double > loop to determine which slaves have requested work. The search is > always started at lowest slave. This leads to unfairness; lower VFs > tends to be prioritized over higher VFs. > > The patch uses find_next_bit to determine which slaves to handle. > Fairness is implemented by always starting at the next to the last > start. > > An MPI program has been used to measure improvements. It runs 500 > ibv_reg_mr, synchronizes with all other instances and then runs 500 > ibv_dereg_mr. > > The results running 500 processes, time reported is for running 500 > calls: > > ibv_reg_mr: > Mod. Org. > mlx4_1 403.356ms 424.674ms > mlx4_2 403.355ms 424.674ms > mlx4_3 403.354ms 424.674ms > mlx4_4 403.355ms 424.674ms > mlx4_5 403.357ms 424.677ms > mlx4_6 403.354ms 424.676ms > mlx4_7 403.357ms 424.675ms > mlx4_8 403.355ms 424.675ms > > ibv_dereg_mr: > Mod. Org. > mlx4_1 116.408ms 142.818ms > mlx4_2 116.434ms 142.793ms > mlx4_3 116.488ms 143.247ms > mlx4_4 116.679ms 143.230ms > mlx4_5 112.017ms 107.204ms > mlx4_6 112.032ms 107.516ms > mlx4_7 112.083ms 184.195ms > mlx4_8 115.089ms 190.618ms > > Suggested-by: Håkon Bugge > Signed-off-by: Hans Westgaard Ry > --- > drivers/net/ethernet/mellanox/mlx4/cmd.c | 75 +++++++++++++++++-------------- > drivers/net/ethernet/mellanox/mlx4/mlx4.h | 1 + > 2 files changed, 43 insertions(+), 33 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c > index c678344d22a2..24989e96ab9d 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/cmd.c > +++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c > @@ -51,7 +51,6 @@ > #include "fw.h" > #include "fw_qos.h" > #include "mlx4_stats.h" > - > #define CMD_POLL_TOKEN 0xffff > #define INBOX_MASK 0xffffffffffffff00ULL > > @@ -2241,48 +2240,58 @@ void mlx4_master_comm_channel(struct work_struct *work) > struct mlx4_priv *priv = > container_of(mfunc, struct mlx4_priv, mfunc); > struct mlx4_dev *dev = &priv->dev; > - __be32 *bit_vec; > u32 comm_cmd; > - u32 vec; > - int i, j, slave; > + int i, slave; > int toggle; > int served = 0; > int reported = 0; > u32 slt; > - > - bit_vec = master->comm_arm_bit_vector; > - for (i = 0; i < COMM_CHANNEL_BIT_ARRAY_SIZE; i++) { > - vec = be32_to_cpu(bit_vec[i]); > - for (j = 0; j < 32; j++) { > - if (!(vec & (1 << j))) > - continue; > - ++reported; > - slave = (i * 32) + j; > - comm_cmd = swab32(readl( > - &mfunc->comm[slave].slave_write)); > - slt = swab32(readl(&mfunc->comm[slave].slave_read)) > - >> 31; > - toggle = comm_cmd >> 31; > - if (toggle != slt) { > - if (master->slave_state[slave].comm_toggle > - != slt) { > - pr_info("slave %d out of sync. read toggle %d, state toggle %d. Resynching.\n", > - slave, slt, > - master->slave_state[slave].comm_toggle); > - master->slave_state[slave].comm_toggle = > - slt; > - } > - mlx4_master_do_cmd(dev, slave, > - comm_cmd >> 16 & 0xff, > - comm_cmd & 0xffff, toggle); > - ++served; > + u32 lbit_vec[COMM_CHANNEL_BIT_ARRAY_SIZE]; > + u32 nmbr_bits; > + u32 prev_slave; > + bool first = true; > + > + for (i = 0; i < COMM_CHANNEL_BIT_ARRAY_SIZE; i++) > + lbit_vec[i] = be32_to_cpu(master->comm_arm_bit_vector[i]); > + nmbr_bits = dev->persist->num_vfs + 1; > + if (++priv->next_slave >= nmbr_bits) > + priv->next_slave = 0; > + slave = priv->next_slave; > + while (true) { > + slave = find_next_bit((const unsigned long *)&lbit_vec, nmbr_bits, slave); > + if (!first && slave >= priv->next_slave) { > + break; > + } else if (slave == nmbr_bits) { > + if (!first) > + break; > + first = false; > + slave = 0; > + continue; > + } > + ++reported; > + comm_cmd = swab32(readl(&mfunc->comm[slave].slave_write)); > + slt = swab32(readl(&mfunc->comm[slave].slave_read)) >> 31; > + toggle = comm_cmd >> 31; > + if (toggle != slt) { > + if (master->slave_state[slave].comm_toggle > + != slt) { > + pr_info("slave %d out of sync. read toggle %d, state toggle %d. Resynching.\n", > + slave, slt, > + master->slave_state[slave].comm_toggle); > + master->slave_state[slave].comm_toggle = > + slt; > } > + mlx4_master_do_cmd(dev, slave, > + comm_cmd >> 16 & 0xff, > + comm_cmd & 0xffff, toggle); > + ++served; > } > + prev_slave = slave++; > } > > if (reported && reported != served) > - mlx4_warn(dev, "Got command event with bitmask from %d slaves but %d were served\n", > - reported, served); > + mlx4_warn(dev, "Got command event with bitmask from %d slaves but %d were served %x %d\n", > + reported, served, lbit_vec[0], priv->next_slave); > > if (mlx4_ARM_COMM_CHANNEL(dev)) > mlx4_warn(dev, "Failed to arm comm channel events\n"); > diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4.h b/drivers/net/ethernet/mellanox/mlx4/mlx4.h > index 64bed7ac3836..cd6ba80f4c90 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/mlx4.h > +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4.h > @@ -924,6 +924,7 @@ struct mlx4_priv { > > atomic_t opreq_count; > struct work_struct opreq_task; > + u32 next_slave; /* mlx4_master_comm_channel */ > }; > > static inline struct mlx4_priv *mlx4_priv(struct mlx4_dev *dev)