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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS 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 3683DC10F0E for ; Fri, 12 Apr 2019 14:14:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F125920850 for ; Fri, 12 Apr 2019 14:14:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="P6a0VI7z" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726978AbfDLOOQ (ORCPT ); Fri, 12 Apr 2019 10:14:16 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:51876 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726711AbfDLOOQ (ORCPT ); Fri, 12 Apr 2019 10:14:16 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3CEAcBf192576; Fri, 12 Apr 2019 14:14:03 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=bGNr2bNF9zPMPBOf6iXYHxRclpUpvUUNKwzCvvoEZns=; b=P6a0VI7z7akJn0xpbERiwcIcSOohvx2IWYCIB+54018Sd4jHZ9Dh2DSfVu+dNKkmnLMP TYDJ0OLy2P8mwjdMOGLDdz5hxnwvluOzPjc8B/oImopZRQSghphXfc9C+Hw/G/6LJUm9 S6zGMr8rHM4e6uO5ZwOWQ9eX1P2a4VbzeelZi6+PsYiAk1FbdNLOuKkUda6/hKjky1NT A+JqN6DQbnkiMbB9lcBp8JSfLMqWvg/JyMS+3sUPx3Q3tSVS9ZlC27ZSIcx9hzsuKdic NE9vg+K7bBm7o5pWuIy7tkPi7nJCBxZJFU7lbwmEJvANAMw1AkNlEmLmaJp2pXPqtiG6 ng== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2rpkhterkq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 12 Apr 2019 14:14:03 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3CEDBlE093705; Fri, 12 Apr 2019 14:14:03 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userp3030.oracle.com with ESMTP id 2rtqnp3y4q-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 12 Apr 2019 14:14:03 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x3CEE01r005826; Fri, 12 Apr 2019 14:14:00 GMT Received: from [10.211.46.126] (/10.211.46.126) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 12 Apr 2019 07:14:00 -0700 Subject: Re: [PATCH 1/1] swiotlb: save io_tlb_used to local variable before leaving critical section To: Dongli Zhang , iommu@lists.linux-foundation.org, konrad.wilk@oracle.com Cc: linux-kernel@vger.kernel.org, hch@lst.de, m.szyprowski@samsung.com, robin.murphy@arm.com, haakon.bugge@oracle.com References: <1555069106-2964-1-git-send-email-dongli.zhang@oracle.com> From: Joe Jin Message-ID: <5bdc3265-e5a4-e8c8-9098-0bba18a66f19@oracle.com> Date: Fri, 12 Apr 2019 07:13:59 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <1555069106-2964-1-git-send-email-dongli.zhang@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9224 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904120094 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9224 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904120093 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'm good to have this patch, which helps identify the cause of failure is fragmentation or it really been used up. On 4/12/19 4:38 AM, Dongli Zhang wrote: > When swiotlb is full, the kernel would print io_tlb_used. However, the > result might be inaccurate at that time because we have left the critical > section protected by spinlock. > > Therefore, we backup the io_tlb_used into local variable before leaving > critical section. > > Fixes: 83ca25948940 ("swiotlb: dump used and total slots when swiotlb buffer is full") > Suggested-by: Håkon Bugge > Signed-off-by: Dongli Zhang Reviewed-by: Joe Jin Thanks, Joe