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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,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 8FE74C433DF for ; Thu, 27 Aug 2020 14:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66F982054F for ; Thu, 27 Aug 2020 14:56:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="eK6ViccI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728295AbgH0O4s (ORCPT ); Thu, 27 Aug 2020 10:56:48 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:55912 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726968AbgH0O4n (ORCPT ); Thu, 27 Aug 2020 10:56:43 -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 07REnLuC119443; Thu, 27 Aug 2020 14:56:31 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-2020-01-29; bh=i0cvgVD9mKaurEeb+8oLNxEBRbao060MNxXFZb6HaGo=; b=eK6ViccIsPw4TfUld5EEmWECzCo09zfXbL0Fd9MDG3mIq9wMv7sYOoGYuNAqRSJCKvVR EFKvuL3n6K+ajWw+V+dzIsPZEcGdgSGfdiafFyes7sNlaoW9lXkHwanKsLRxlxJrqUQl XVpa5ZPmERyDRGnosjLMf1FmVRqScJw/whI/lysHV4ic/F7rRZ+/C8Kb6shqA+OTg5Cd O/+Gi4qkHDn9FeQpsS6CH9Hlw8A9BaD73qUsXHfs3G7Cy1wxJYN8cSJIhCXD00OpzVMp iiBnfNVfpv3HzBGE3fRlUNpZt9TaeqKaA01FKQHIQReCL3BtwkS9I9plGxXk6T16PyVm +g== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2120.oracle.com with ESMTP id 333w6u5dp0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 27 Aug 2020 14:56:31 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 07REotcF020173; Thu, 27 Aug 2020 14:56:30 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 333r9ngwb8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 27 Aug 2020 14:56:30 +0000 Received: from abhmp0004.oracle.com (abhmp0004.oracle.com [141.146.116.10]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 07REuS1S013544; Thu, 27 Aug 2020 14:56:29 GMT Received: from [192.168.2.112] (/50.38.35.18) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 27 Aug 2020 07:56:27 -0700 Subject: Re: [drm/mgag200] 913ec479bb: vm-scalability.throughput 26.2% improvement To: Thomas Zimmermann , kernel test robot Cc: John Donnelly , Emil Velikov , LKML , lkp@lists.01.org, lkp@intel.com, ying.huang@intel.com, feng.tang@intel.com, zhengjun.xing@intel.com References: <20200826085847.GL4299@shao2-debian> <76926ade-15fb-75a3-17aa-a2b5a68471c8@suse.de> From: Mike Kravetz Message-ID: <99c7683c-f428-378d-2b19-ef51270a5d8e@oracle.com> Date: Thu, 27 Aug 2020 07:56:26 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <76926ade-15fb-75a3-17aa-a2b5a68471c8@suse.de> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9726 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 mlxscore=0 bulkscore=0 adultscore=0 spamscore=0 mlxlogscore=999 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008270114 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9725 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 impostorscore=0 mlxlogscore=999 suspectscore=0 phishscore=0 malwarescore=0 spamscore=0 priorityscore=1501 clxscore=1011 mlxscore=0 lowpriorityscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008270114 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/27/20 2:16 AM, Thomas Zimmermann wrote: > Hi > > Am 26.08.20 um 10:58 schrieb kernel test robot: >> Greeting, >> >> FYI, we noticed a 26.2% improvement of vm-scalability.throughput due to commit: > > I guess this resolves the once-measured performance penalty of similar > magnitude. But do we really understand these tests? When I sent out > patches to resolve the problem, nothing changed. And suddenly the > performance is back to normal. > > Best regards > Thomas > >> >> >> commit: 913ec479bb5cc27f99f24d5fd111b3ef29a4deb9 ("drm/mgag200: Replace VRAM helpers with SHMEM helpers") >> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master >> >> >> in testcase: vm-scalability >> on test machine: 288 threads Intel(R) Xeon Phi(TM) CPU 7295 @ 1.50GHz with 80G memory >> with following parameters: >> >> runtime: 300s >> size: 8T >> test: anon-cow-seq-hugetlb >> cpufreq_governor: performance >> ucode: 0x11 Hello Thomas, Did drm changes really impact anon-cow-seq-hugetlb performance? My change c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization") caused a -33.4% regression of anon-cow-seq-hugetlb. A recent change 34ae204f185 (hugetlbfs: remove call to huge_pte_alloc without i_mmap_rwsem) was tested by Zhengjun Xing and improved performance by 20 something percent. That seems in line with this report/improvement. Perhaps the tooling is not always accurate in determining the commit which causes the performance changes? Perhaps I am misreading information in the reports? -- Mike Kravetz