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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDF72C5B543 for ; Tue, 10 Jun 2025 08:14:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6875A6B0092; Tue, 10 Jun 2025 04:14:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 638646B0095; Tue, 10 Jun 2025 04:14:14 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 526E06B0096; Tue, 10 Jun 2025 04:14:14 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 317D06B0092 for ; Tue, 10 Jun 2025 04:14:14 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 04166BF04B for ; Tue, 10 Jun 2025 08:14:12 +0000 (UTC) X-FDA: 83538778386.10.9599095 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by imf21.hostedemail.com (Postfix) with ESMTP id 677E41C0005 for ; Tue, 10 Jun 2025 08:14:10 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=IhC33tLx; spf=pass (imf21.hostedemail.com: domain of donettom@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=donettom@linux.ibm.com; dmarc=pass (policy=none) header.from=ibm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749543250; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=r8hdw9Rw+PQqw6yzY+29b7k2yuPuh90hDJNW2Q1IHMo=; b=s7Kz1os3r0J9Ho3eFUiqSZG+dY/4lky5tL2S5ljASQXBBB0/RU5vDeIFDq3GBn2dGE/oPd nANuIY4lxMKI1xsDW+vy15+YandDeROOClb68jJb9Y9EIeK3vdZAOmwd8JJg3cbwwj4Idi enGsaFyKvhiCRbSho2SIcYrC14QVLfg= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=ibm.com header.s=pp1 header.b=IhC33tLx; spf=pass (imf21.hostedemail.com: domain of donettom@linux.ibm.com designates 148.163.156.1 as permitted sender) smtp.mailfrom=donettom@linux.ibm.com; dmarc=pass (policy=none) header.from=ibm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1749543250; a=rsa-sha256; cv=none; b=VSZhTCZ4uJ2m1w5zGjrbUSRZNWC/k5lyO+/WBm0gqdyrkfxQatvxi1lBAsIkWvv7qkYQy6 9juW+kZob9McpehQYQNV5m1VN8QNyp2+VOLj+/CqRGScKFH3VtkseEUCJCOb+f0rAyfCux wXstmBEM+4Nqlcb0L3QcfacgWQpBkBg= Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 55A09sUg032702; Tue, 10 Jun 2025 08:14:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=pp1; bh=r8hdw9 Rw+PQqw6yzY+29b7k2yuPuh90hDJNW2Q1IHMo=; b=IhC33tLxO+dooNeWGK/vf6 pOvEyJxqxsMe3+21baki9WNUXyq8r3EtqBf26whr/FwCN4d8jGkryXwbNk/wEfwD RoeCUm+xdTpLnQ55/G9nIxrwYos4aQLEInnoraqfAv/Mxh1LdyepaXDJ0RiYPNm5 NBjEUDOujFbaIX8WQkTEzO8OOpM9eiRBSQQ6KF7szTeSTNwF3Bz1k6DEE5Ul4qvn TQt655Hdob8wEReDTp5dtJcVKyU949RnYcAaJeeoVMC31fDBGty1j4LwyczWNFjD IANEY3sh+tnSo3YLraNPzbEcLATwfcqTpXFE6C9yUy11FtSmRXf7BFyjSprvzGsg == Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4769wyhpfk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Jun 2025 08:14:06 +0000 (GMT) Received: from m0356517.ppops.net (m0356517.ppops.net [127.0.0.1]) by pps.reinject (8.18.0.8/8.18.0.8) with ESMTP id 55A8E66m015831; Tue, 10 Jun 2025 08:14:06 GMT Received: from ppma13.dal12v.mail.ibm.com (dd.9e.1632.ip4.static.sl-reverse.com [50.22.158.221]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4769wyhpff-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Jun 2025 08:14:06 +0000 (GMT) Received: from pps.filterd (ppma13.dal12v.mail.ibm.com [127.0.0.1]) by ppma13.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 55A61l4E003463; Tue, 10 Jun 2025 08:14:05 GMT Received: from smtprelay02.wdc07v.mail.ibm.com ([172.16.1.69]) by ppma13.dal12v.mail.ibm.com (PPS) with ESMTPS id 4751ykh97w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 10 Jun 2025 08:14:05 +0000 Received: from smtpav04.wdc07v.mail.ibm.com (smtpav04.wdc07v.mail.ibm.com [10.39.53.231]) by smtprelay02.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 55A8E4SI31261336 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 10 Jun 2025 08:14:04 GMT Received: from smtpav04.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C3F9C58045; Tue, 10 Jun 2025 08:14:04 +0000 (GMT) Received: from smtpav04.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DF79D58054; Tue, 10 Jun 2025 08:14:02 +0000 (GMT) Received: from [9.109.245.113] (unknown [9.109.245.113]) by smtpav04.wdc07v.mail.ibm.com (Postfix) with ESMTP; Tue, 10 Jun 2025 08:14:02 +0000 (GMT) Message-ID: <0b9e1e55-f4c9-4e30-abe6-3b9765ba9ebf@linux.ibm.com> Date: Tue, 10 Jun 2025 13:44:01 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/memory-tier: Fix abstract distance calculation overflow To: Li Zhijian , linux-mm@kvack.org Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Ying Huang References: <20250610062751.2365436-1-lizhijian@fujitsu.com> Content-Language: en-US From: Donet Tom In-Reply-To: <20250610062751.2365436-1-lizhijian@fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: xmceErOpFt8yCePtbSQsA-WmXVmkl-pq X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNjEwMDA1OCBTYWx0ZWRfX1TK7gdleShsC ZlZL227d1dnBeXmMwCzS2BZrqqKeM+XQP9A/2KYiK6yJeQHfb6f9h3Qd2L29Smg1FG3oO/sLUi7 XdZgarrGFWP0CO7BZ0mLnVsmjYHH1VuXd0KsecD4KPoY4pBM6PtJNUq8LsiGopra3ZvWZme0SAA pg/X4UE6gFIRhawMLExLl5XyHPnxmNFrEiLh+dXZGwHcMFwgkgVyi1Cb9J8GAp4YkThLoV1DzqD /XljKsKhI+MifNstt2oQmV/LpcwpbpUvQG/LfJuSS2TGK1lyuwULWxvb3KQcFy8UKRir0xtkZkY 6SiWRB1xJntae2+7d6HMjGzXitp356xZWfEovwh7U9uk7gVxXAqkSu62o1aUZCppeV8DIdFWhGS 6emig6fwRqAMbtLKq1hGCp/dKzyHOvbw3xjnrROQ+AR7rusllOd6uvJoxSpCMfZI13vzFZ3k X-Authority-Analysis: v=2.4 cv=YKGfyQGx c=1 sm=1 tr=0 ts=6847e94e cx=c_pps a=AfN7/Ok6k8XGzOShvHwTGQ==:117 a=AfN7/Ok6k8XGzOShvHwTGQ==:17 a=IkcTkHD0fZMA:10 a=6IFa9wvqVegA:10 a=pGLkceISAAAA:8 a=omOdbC7AAAAA:8 a=VnNF1IyMAAAA:8 a=MjiR9eHTnMDsPQ3Rr7EA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-GUID: hLWlauVIk4vxWRo7QYfEL2eAP_IZVkSd X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-06-10_02,2025-06-09_02,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 clxscore=1011 malwarescore=0 bulkscore=0 priorityscore=1501 phishscore=0 mlxscore=0 lowpriorityscore=0 impostorscore=0 adultscore=0 mlxlogscore=999 suspectscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505280000 definitions=main-2506100058 X-Stat-Signature: hf87dgxxcpq6ir466eqd1zt4fghpswgb X-Rspamd-Queue-Id: 677E41C0005 X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1749543250-215720 X-HE-Meta: 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 u95MTrJG ruuvz/xuQ+L0Iea3gRc90+DyNKseB4vtJ2bK4LOcHpe5c/tKmrEGLujhdhAvB1gIeUqTpI7Uh/I20GBX+iyLryZlCDTyfQNTIEGQFk74pa9H7tEwF9MR+jRFJL4dhsoofalj0uQ3XJxeM0Hi9AQm3aeXxfoNGb4E26OlEcONE7/JeqSbnh7HRX0O9D62pVXiNWgAePyER5EdJTZbe5KwG9RFBmPcTRrls9+BUX9YOiVi1LXPHEYThdTyg67hfYWJ9jD+Md92PgwnSskWW1y6UMZV7RBRoPPiqdv13718/ASHwUEjDIvkrcdypeOmSoFMH8a0JQRKU4x0ZMfBnNRZbDx8l4Z7xySJ4UXIMAHOZe+lH+TybFVzVUGO4JJano0M7wUtDjnEV5RFwZjhdJ0Oggx7lozSZIC7SRlvWmFJvbz5fWKsT2rrgGM088ZGaWKh7GGPtN78GGlMq28M= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/10/25 11:57 AM, Li Zhijian wrote: > In mt_perf_to_adistance(), the calculation of abstract distance (adist) > involves multiplying several int values including MEMTIER_ADISTANCE_DRAM. > ``` > *adist = MEMTIER_ADISTANCE_DRAM * > (perf->read_latency + perf->write_latency) / > (default_dram_perf.read_latency + default_dram_perf.write_latency) * > (default_dram_perf.read_bandwidth + default_dram_perf.write_bandwidth) / > (perf->read_bandwidth + perf->write_bandwidth); > ``` > Since these values can be large, the multiplication may exceed the maximum > value of an int (INT_MAX) and overflow (Our platform did), leading to an > incorrect adist. > > Change MEMTIER_ADISTANCE_DRAM to be a long constant by writing it with the > 'L' suffix. This prevents the overflow because the multiplication will then > be done in the long type which has a larger range. > > Fixes: 3718c02dbd4c ("acpi, hmat: calculate abstract distance with HMAT") > Cc: Ying Huang > Signed-off-by: Li Zhijian > --- > include/linux/memory-tiers.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h > index 0dc0cf2863e2..7a805796fcfd 100644 > --- a/include/linux/memory-tiers.h > +++ b/include/linux/memory-tiers.h > @@ -18,7 +18,7 @@ > * adistance value (slightly faster) than default DRAM adistance to be part of > * the same memory tier. > */ > -#define MEMTIER_ADISTANCE_DRAM ((4 * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1)) > +#define MEMTIER_ADISTANCE_DRAM ((4L * MEMTIER_CHUNK_SIZE) + (MEMTIER_CHUNK_SIZE >> 1)) Hi Li Zhijian This looks good to me. Feel free to add Reviewed-byDonet Tom > > struct memory_tier; > struct memory_dev_type {