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=-8.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 3FC00C41604 for ; Sat, 3 Oct 2020 21:45:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0145A206C3 for ; Sat, 3 Oct 2020 21:45:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="fhs9FvBN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726030AbgJCVpp (ORCPT ); Sat, 3 Oct 2020 17:45:45 -0400 Received: from hqnvemgate25.nvidia.com ([216.228.121.64]:6588 "EHLO hqnvemgate25.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbgJCVpj (ORCPT ); Sat, 3 Oct 2020 17:45:39 -0400 Received: from hqmail.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate25.nvidia.com (using TLS: TLSv1.2, AES256-SHA) id ; Sat, 03 Oct 2020 14:44:45 -0700 Received: from [10.21.38.85] (172.20.13.39) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Sat, 3 Oct 2020 21:45:30 +0000 Subject: Re: reduce iSERT Max IO size To: Krishnamraju Eraparaju , Sagi Grimberg CC: , Potnuri Bharat Teja , Max Gurtovoy References: <20200922104424.GA18887@chelsio.com> <07e53835-8389-3e07-6976-505edbd94f2a@grimberg.me> <20201002171007.GA16636@chelsio.com> <4d0b1a3f-2980-c7ed-ef9a-0ed6a9c87a69@grimberg.me> <20201003033644.GA19516@chelsio.com> From: Max Gurtovoy Message-ID: <4391e240-5d6d-fb59-e6fb-e7818d1d0bd2@nvidia.com> Date: Sun, 4 Oct 2020 00:45:26 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 In-Reply-To: <20201003033644.GA19516@chelsio.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [172.20.13.39] X-ClientProxiedBy: HQMAIL107.nvidia.com (172.20.187.13) To HQMAIL107.nvidia.com (172.20.187.13) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1601761485; bh=fG8BFWUbYdfQxEM2Qpsrk8+/LWgwgpNP+Y0z8Q0qo/o=; h=Subject:To:CC:References:From:Message-ID:Date:User-Agent: MIME-Version:In-Reply-To:Content-Type:Content-Transfer-Encoding: Content-Language:X-Originating-IP:X-ClientProxiedBy; b=fhs9FvBNF5ddB7RsSbj98kLnxoAYcVcl6qiL4QEGrpiUuHD6Z1a4PkOQTLMPvhqxv M3QBcLWSG3sCMH32TdT607t6C2Bn3bwB+iYWfyog4UJznjwidZUeZzGeE/39eH/2O3 CjHYaeIQGrixdsQj3KI3mMDd2eINcaimD9Zx+mjxWuOAQ3P2WxZB4JfjAa8JIhi/8M iNn8Ug/qOfFnYwUyFjms2WbX4naaICMfKmzM6/m2Qw9+JYol+FjXNf1hUEYbU3fZBZ EKS6CxSzTZSY8hogLmrngqQAjGAvlNbBIIXlVG5chjdFOaY3JleewAGzHiWAGZbtbF 3f3ZxUsH2xQ8g== Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 10/3/2020 6:36 AM, Krishnamraju Eraparaju wrote: > On Friday, October 10/02/20, 2020 at 13:29:30 -0700, Sagi Grimberg wrote: >>> Hi Sagi & Max, >>> >>> Any update on this? >>> Please change the max IO size to 1MiB(256 pages). >> I think that the reason why this was changed to handle the worst case >> was in case there are different capabilities on the initiator and the >> target with respect to number of pages per MR. There is no handshake >> that aligns expectations. > But, the max pages per MR supported by most adapters is around 256 pages > only. > And I think only those iSER initiators, whose max pages per MR is 4096, > could send 16MiB sized IOs, am I correct? If the initiator can send 16MiB, we must make sure the target is capable to receive it. > >> If we revert that it would restore the issue that you reported in the >> first place: >> >> -- >> IB/isert: allocate RW ctxs according to max IO size > I don't see the reported issue after reducing the IO size to 256 > pages(keeping all other changes of this patch intact). > That is, "attr.cap.max_rdma_ctxs" is now getting filled properly with > "rdma_rw_mr_factor()" related changes, I think. > > Before this change "attr.cap.max_rdma_ctxs" was hardcoded with > 128(ISCSI_DEF_XMIT_CMDS_MAX) pages, which is very low for single target > and muli-luns case. > > So reverting only ISCSI_ISER_MAX_SG_TABLESIZE macro to 256 doesn't cause the > reported issue. > > Thanks, > Krishnam Raju. >> Current iSER target code allocates MR pool budget based on queue size. >> Since there is no handshake between iSER initiator and target on max IO >> size, we'll set the iSER target to support upto 16MiB IO operations and >> allocate the correct number of RDMA ctxs according to the factor of MR's >> per IO operation. This would guaranty sufficient size of the MR pool for >> the required IO queue depth and IO size. >> >> Reported-by: Krishnamraju Eraparaju >> Tested-by: Krishnamraju Eraparaju >> Signed-off-by: Max Gurtovoy >> -- >> >>> >>> Thanks, >>> Krishnam Raju. >>> On Wednesday, September 09/23/20, 2020 at 01:57:47 -0700, Sagi Grimberg wrote: >>>>> Hi, >>>>> >>>>> Please reduce the Max IO size to 1MiB(256 pages), at iSER Target. >>>>> The PBL memory consumption has increased significantly after increasing >>>>> the Max IO size to 16MiB(with commit:317000b926b07c). >>>>> Due to the large MR pool, the max no.of iSER connections(On one variant >>>>> of Chelsio cards) came down to 9, before it was 250. >>>>> NVMe-RDMA target also uses 1MiB max IO size. >>>> Max, remind me what was the point to support 16M? Did this resolve >>>> an issue?