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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 9778CC3A59F for ; Mon, 26 Aug 2019 14:39:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6818A20874 for ; Mon, 26 Aug 2019 14:39:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="b2knjo1I" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729951AbfHZOjb (ORCPT ); Mon, 26 Aug 2019 10:39:31 -0400 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:20597 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729753AbfHZOjb (ORCPT ); Mon, 26 Aug 2019 10:39:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1566830370; x=1598366370; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=Vbn1kZPOKFt5j/QtS7xdD6lJRyn0mgeYEO0bNq8dq+c=; b=b2knjo1IeyCW1RvdJhS1heqcEmL3aWXvyHrtNJ8JhBup+xJoWvnVfj3k YaflhOi4pOigXEkPvdZrkjIriAt/AUrC/HlnZ61NXXTJeeGPOywzOiy6r Jz07EU/ZD4ai/xjA3Hd+A75/796c+HSf+GmS60Jr4Ed1b0f+6evca5yJD g=; X-IronPort-AV: E=Sophos;i="5.64,433,1559520000"; d="scan'208";a="781515266" Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2b-baacba05.us-west-2.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 26 Aug 2019 14:39:28 +0000 Received: from EX13MTAUEA001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-baacba05.us-west-2.amazon.com (Postfix) with ESMTPS id 1D319A215B; Mon, 26 Aug 2019 14:39:28 +0000 (UTC) Received: from EX13D19EUB003.ant.amazon.com (10.43.166.69) by EX13MTAUEA001.ant.amazon.com (10.43.61.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 26 Aug 2019 14:39:27 +0000 Received: from 8c85908914bf.ant.amazon.com (10.43.162.222) by EX13D19EUB003.ant.amazon.com (10.43.166.69) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Mon, 26 Aug 2019 14:39:24 +0000 Subject: Re: ib_umem_get and DMA_API_DEBUG question To: Leon Romanovsky CC: RDMA mailing list References: <526c5b18-5853-c8dc-e112-31287a46e707@amazon.com> <20190826142320.GD4584@mtr-leonro.mtl.com> From: Gal Pressman Message-ID: Date: Mon, 26 Aug 2019 17:39:19 +0300 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190826142320.GD4584@mtr-leonro.mtl.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.43.162.222] X-ClientProxiedBy: EX13D01UWB004.ant.amazon.com (10.43.161.157) To EX13D19EUB003.ant.amazon.com (10.43.166.69) Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 26/08/2019 17:23, Leon Romanovsky wrote: > On Mon, Aug 26, 2019 at 05:05:12PM +0300, Gal Pressman wrote: >> Hi all, >> >> Lately I've been seeing DMA-API call traces on our automated testing runs which >> complain about overlapping mappings of the same cacheline [1]. >> The problem is (most likely) caused due to multiple calls to ibv_reg_mr with the >> same address, which as a result DMA maps the same physical addresses more than 7 >> (ACTIVE_CACHELINE_MAX_OVERLAP) times. >> >> Is this considered a bad behavior by the test? Should this be caught by >> ib_core/driver somehow? > > If I'm not mistaken here, but we (Mellanox) decided that it is a bug in > DMA debug code. Thanks a lot Leon, good to know that it's not just an EFA thing. In case you remember, is it a bug in the sense that the trace is a false alarm or is it a bug that could cause real issues? Did you guys by any chance analyze what are the consequences of this?