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=-8.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,RCVD_ILLEGAL_IP,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 D04CEC43461 for ; Thu, 3 Sep 2020 20:35:26 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 557A420658 for ; Thu, 3 Sep 2020 20:35:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="LwXGg0mn"; dkim=pass (1024-bit key) header.d=fb.onmicrosoft.com header.i=@fb.onmicrosoft.com header.b="M+2qfHU9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 557A420658 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B8797900003; Thu, 3 Sep 2020 16:35:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B37E4900002; Thu, 3 Sep 2020 16:35:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9B60D900003; Thu, 3 Sep 2020 16:35:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0136.hostedemail.com [216.40.44.136]) by kanga.kvack.org (Postfix) with ESMTP id 7F561900002 for ; Thu, 3 Sep 2020 16:35:25 -0400 (EDT) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3CA9F181AC9CB for ; Thu, 3 Sep 2020 20:35:25 +0000 (UTC) X-FDA: 77222905410.27.knee19_35089d6270ac Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin27.hostedemail.com (Postfix) with ESMTP id 0D03F3D669 for ; Thu, 3 Sep 2020 20:35:25 +0000 (UTC) X-HE-Tag: knee19_35089d6270ac X-Filterd-Recvd-Size: 17552 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Sep 2020 20:35:23 +0000 (UTC) Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 083KXwGN024434; Thu, 3 Sep 2020 13:34:32 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=facebook; bh=RvA/HSU7hsn38Sd1lcLoMPq6VzQ0ovMIPkqfZ0/bj6g=; b=LwXGg0mnLMfUKWLazwrq+yzJzr+36r+tLilOcM6FElaNIukbeQogKw3xv5OT6xhFw0ym 7w5VpTINJcumtUnSsxn3mrUokf0Rf7bJe2s5II0ji8xv7oqDQbrIpaRI9k5Srw6VX7YB CA8PPdb+YxHREb78DdTc6ADrooZBNSVkU7Q= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 33879p1t4u-12 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 03 Sep 2020 13:34:32 -0700 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (100.104.31.183) by o365-in.thefacebook.com (100.104.36.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Thu, 3 Sep 2020 13:34:30 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Tdp1eJ+v/8qTtXKwOeIFmW+8xuxpcHgfW/iXkKNKrlv43Dkmg138/0jEUBw74Cvj/LKdGS3iebig+xW8CWb3mmu2hyxNQRuahoRkx6VjFsnbPnDRMhc+KSb8ENvpmT5mfcmBR28BJsjSXID12imojzNiJvN2vUGH9UbClSHQ8adbmWFOJsi+pHDWjDHFRTQVdULssNITusBDv2YqQOnUWl+dyo0Rc0nQN9eELVDpPBupWcA+LXvwVwOTGj/OsjY5/KDZudJyd/2tptarBXbekvr2RDi1qgSKuH2et2PkKTUH+YsBDr4ikj7ii1fuMCwJo7tMusbWcWvBYcA3HAGSWw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=RvA/HSU7hsn38Sd1lcLoMPq6VzQ0ovMIPkqfZ0/bj6g=; b=NULf/j3LHOYa8y1X2jdBNOD0Ov+Bl6SVsCI6e7S7Un5/fycQKORaj6QmzgE4aYwI1+YBEdaMaI7rwbZs/xf/Qy7Ob7lIdLFKEHGhV3or+xKXIoGx+iDjlNH24TSbYSPpX2ofiJq6NEhc9KU1/bmhChqMAC6371oZ5SMMk4mtXI5fYpagjhKm72rwAynL+iHD0I94unsFMIBuksG3F+HFcKFAoBZY74Vi2184vwTYIRNeeAxSJnJVK9mBJgw/UMDYj2ustGfyTOAkAm7+Jpx5154pnbblrvNVp48zC7ar2ELJpE9t5pfBXW0OvhnRS/TRtUcKajRTMCBbkhAArYHsbg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=fb.com; dmarc=pass action=none header.from=fb.com; dkim=pass header.d=fb.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.onmicrosoft.com; s=selector2-fb-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=RvA/HSU7hsn38Sd1lcLoMPq6VzQ0ovMIPkqfZ0/bj6g=; b=M+2qfHU9iX6k9NXRFbQvnUuCPKdXkw0RsR1C7JR7Hvt2w1AjUxuhxVwjrIn3LrcXt97KkcbyMleIRbjEmqTOBvdxCVxrVlnZXzOIHQzT7fPdG/domhgkbYLQkwRLYjWVRc+F7f/mjMgsPWjiEnJm3Qvx/nMg7phNIHKd6EI5amw= Authentication-Results: oracle.com; dkim=none (message not signed) header.d=none;oracle.com; dmarc=none action=none header.from=fb.com; Received: from BYAPR15MB4136.namprd15.prod.outlook.com (2603:10b6:a03:96::24) by BYAPR15MB2503.namprd15.prod.outlook.com (2603:10b6:a02:89::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3326.25; Thu, 3 Sep 2020 20:34:28 +0000 Received: from BYAPR15MB4136.namprd15.prod.outlook.com ([fe80::354d:5296:6a28:f55e]) by BYAPR15MB4136.namprd15.prod.outlook.com ([fe80::354d:5296:6a28:f55e%6]) with mapi id 15.20.3348.016; Thu, 3 Sep 2020 20:34:28 +0000 Date: Thu, 3 Sep 2020 13:34:24 -0700 From: Roman Gushchin To: Mike Kravetz CC: , , , , Barry Song , Joonsoo Kim , Rik van Riel , Aslan Bakirov , Michal Hocko , Andrew Morton Subject: Re: [RFC PATCH] cma: make number of CMA areas dynamic, remove CONFIG_CMA_AREAS Message-ID: <20200903203424.GH60440@carbon.dhcp.thefacebook.com> References: <20200903030204.253433-1-mike.kravetz@oracle.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903030204.253433-1-mike.kravetz@oracle.com> X-ClientProxiedBy: BY5PR16CA0029.namprd16.prod.outlook.com (2603:10b6:a03:1a0::42) To BYAPR15MB4136.namprd15.prod.outlook.com (2603:10b6:a03:96::24) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from 255.255.255.255 (255.255.255.255) by BY5PR16CA0029.namprd16.prod.outlook.com (2603:10b6:a03:1a0::42) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3348.15 via Frontend Transport; Thu, 3 Sep 2020 20:34:27 +0000 X-Originating-IP: [2620:10d:c090:400::5:6903] X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 0147670f-0797-459e-c761-08d85048c15b X-MS-TrafficTypeDiagnostic: BYAPR15MB2503: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-FB-Source: Internal X-MS-Oob-TLC-OOBClassifiers: OLM:3044; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: wjn0fiu6iasvrumFLyF/s3uXERYN00m6vdhw/ru6FzyXfSpu3GoiTtAoerPKnvA8ZXAKk67t5y7muc2b+OiHDFtX8iDQ/wRmcYUja88npUgykRMOcHTtGwDPyEbnCuB3kcGXIPv9fmo8T34Ojk0Xu4khALOOvnk5AShSzY+KpM5xMc999JyFajTEmXiVr/8GbKpEx/Z9rjCZ4X4GaUqQ8r3nH57fPsZ+0l/C90+yvh5k2DwRnUIpAAsTXJpIFjxlqP9gRSjvjEiYIlJoQibCyw6KBk9gQWDqtDsHODp85nKh1liMPuNMZkoL4DZKa1WmW4KJqCrg7gs6lqK2nRrcIg== X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR15MB4136.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(366004)(346002)(376002)(136003)(396003)(39860400002)(2906002)(66556008)(83380400001)(33656002)(9686003)(86362001)(7416002)(956004)(8936002)(478600001)(66476007)(66946007)(6916009)(6486002)(1076003)(5660300002)(186003)(52116002)(4326008)(6666004)(316002)(54906003)(8676002)(16576012);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData: 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 X-MS-Exchange-CrossTenant-Network-Message-Id: 0147670f-0797-459e-c761-08d85048c15b X-MS-Exchange-CrossTenant-AuthSource: BYAPR15MB4136.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Sep 2020 20:34:28.8278 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: XUf3l0ixnF8zmjfMJopVywvteKq0w4xq79rW6IcUm9Kp7Yn9es0j7G9ZoV/Eg/3x X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB2503 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-09-03_13:2020-09-03,2020-09-03 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 impostorscore=0 mlxlogscore=999 spamscore=0 lowpriorityscore=0 bulkscore=0 priorityscore=1501 adultscore=0 malwarescore=0 phishscore=0 mlxscore=0 clxscore=1011 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009030183 X-FB-Internal: deliver X-Rspamd-Queue-Id: 0D03F3D669 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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: On Wed, Sep 02, 2020 at 08:02:04PM -0700, Mike Kravetz wrote: > The number of distinct CMA areas is limited by the constant > CONFIG_CMA_AREAS. In most environments, this was set to a default > value of 7. Not too long ago, support was added to allocate hugetlb > gigantic pages from CMA. More recent changes to make dma_alloc_coherent > NUMA-aware on arm64 added more potential users of CMA areas. Along > with the dma_alloc_coherent changes, the default value of CMA_AREAS > was bumped up to 19 if NUMA is enabled. > > It seems that the number of CMA users is likely to grow. Instead of > using a static array for cma areas, use a simple linked list. These > areas are used before normal memory allocators, so use the memblock > allocator. > > Signed-off-by: Mike Kravetz Sounds like a good idea! That 7 always confused me. Acked-by: Roman Gushchin Thank you! > --- > arch/arm/mm/dma-mapping.c | 29 ++++++++++++------- > arch/mips/configs/cu1000-neo_defconfig | 1 - > arch/mips/configs/cu1830-neo_defconfig | 1 - > include/linux/cma.h | 12 -------- > mm/Kconfig | 12 -------- > mm/cma.c | 40 +++++++++++++------------- > mm/cma.h | 4 +-- > mm/cma_debug.c | 6 ++-- > 8 files changed, 44 insertions(+), 61 deletions(-) > > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c > index 8a8949174b1c..a35a760cc0f4 100644 > --- a/arch/arm/mm/dma-mapping.c > +++ b/arch/arm/mm/dma-mapping.c > @@ -383,25 +383,34 @@ postcore_initcall(atomic_pool_init); > struct dma_contig_early_reserve { > phys_addr_t base; > unsigned long size; > + struct list_head areas; > }; > > -static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata; > - > -static int dma_mmu_remap_num __initdata; > +static __initdata LIST_HEAD(dma_mmu_remap_areas); > > void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) > { > - dma_mmu_remap[dma_mmu_remap_num].base = base; > - dma_mmu_remap[dma_mmu_remap_num].size = size; > - dma_mmu_remap_num++; > + struct dma_contig_early_reserve *d; > + > + d = memblock_alloc(sizeof(struct dma_contig_early_reserve), > + sizeof(void *)); > + if (!d) { > + pr_err("Unable to allocate dma_contig_early_reserve struct!\n"); > + return; > + } > + > + d->base = base; > + d->size = size; > + list_add_tail(&d->areas, &dma_mmu_remap_areas); > } > > void __init dma_contiguous_remap(void) > { > - int i; > - for (i = 0; i < dma_mmu_remap_num; i++) { > - phys_addr_t start = dma_mmu_remap[i].base; > - phys_addr_t end = start + dma_mmu_remap[i].size; > + struct dma_contig_early_reserve *d; > + > + list_for_each_entry(d, &dma_mmu_remap_areas, areas) { > + phys_addr_t start = d->base; > + phys_addr_t end = start + d->size; > struct map_desc map; > unsigned long addr; > > diff --git a/arch/mips/configs/cu1000-neo_defconfig b/arch/mips/configs/cu1000-neo_defconfig > index e924c817f73d..b86f3fd420f2 100644 > --- a/arch/mips/configs/cu1000-neo_defconfig > +++ b/arch/mips/configs/cu1000-neo_defconfig > @@ -31,7 +31,6 @@ CONFIG_HZ_100=y > # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set > # CONFIG_COMPACTION is not set > CONFIG_CMA=y > -CONFIG_CMA_AREAS=7 > CONFIG_NET=y > CONFIG_PACKET=y > CONFIG_UNIX=y > diff --git a/arch/mips/configs/cu1830-neo_defconfig b/arch/mips/configs/cu1830-neo_defconfig > index cbfb62900273..98a31334fc57 100644 > --- a/arch/mips/configs/cu1830-neo_defconfig > +++ b/arch/mips/configs/cu1830-neo_defconfig > @@ -31,7 +31,6 @@ CONFIG_HZ_100=y > # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set > # CONFIG_COMPACTION is not set > CONFIG_CMA=y > -CONFIG_CMA_AREAS=7 > CONFIG_NET=y > CONFIG_PACKET=y > CONFIG_UNIX=y > diff --git a/include/linux/cma.h b/include/linux/cma.h > index 217999c8a762..ea9a3dab0c20 100644 > --- a/include/linux/cma.h > +++ b/include/linux/cma.h > @@ -6,18 +6,6 @@ > #include > #include > > -/* > - * There is always at least global CMA area and a few optional > - * areas configured in kernel .config. > - */ > -#ifdef CONFIG_CMA_AREAS > -#define MAX_CMA_AREAS (1 + CONFIG_CMA_AREAS) > - > -#else > -#define MAX_CMA_AREAS (0) > - > -#endif > - > #define CMA_MAX_NAME 64 > > struct cma; > diff --git a/mm/Kconfig b/mm/Kconfig > index 7d56281ff41e..a52345093f4d 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -513,18 +513,6 @@ config CMA_DEBUGFS > help > Turns on the DebugFS interface for CMA. > > -config CMA_AREAS > - int "Maximum count of the CMA areas" > - depends on CMA > - default 19 if NUMA > - default 7 > - help > - CMA allows to create CMA areas for particular purpose, mainly, > - used as device private area. This parameter sets the maximum > - number of CMA area in the system. > - > - If unsure, leave the default value "7" in UMA and "19" in NUMA. > - > config MEM_SOFT_DIRTY > bool "Track memory changes" > depends on CHECKPOINT_RESTORE && HAVE_ARCH_SOFT_DIRTY && PROC_FS > diff --git a/mm/cma.c b/mm/cma.c > index 7f415d7cda9f..2bd61137b2ca 100644 > --- a/mm/cma.c > +++ b/mm/cma.c > @@ -36,8 +36,9 @@ > > #include "cma.h" > > -struct cma cma_areas[MAX_CMA_AREAS]; > -unsigned cma_area_count; > +/* modify here */ > +LIST_HEAD(cma_areas); > +static unsigned int cma_area_count; > static DEFINE_MUTEX(cma_mutex); > > phys_addr_t cma_get_base(const struct cma *cma) > @@ -143,10 +144,10 @@ static void __init cma_activate_area(struct cma *cma) > > static int __init cma_init_reserved_areas(void) > { > - int i; > + struct cma *c; > > - for (i = 0; i < cma_area_count; i++) > - cma_activate_area(&cma_areas[i]); > + list_for_each_entry(c, &cma_areas, areas) > + cma_activate_area(c); > > return 0; > } > @@ -172,15 +173,14 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, > struct cma *cma; > phys_addr_t alignment; > > - /* Sanity checks */ > - if (cma_area_count == ARRAY_SIZE(cma_areas)) { > - pr_err("Not enough slots for CMA reserved regions!\n"); > - return -ENOSPC; > - } > + /* Do not attempt allocations after memblock allocator is torn down */ > + if (slab_is_available()) > + return -EINVAL; > > if (!size || !memblock_is_region_reserved(base, size)) > return -EINVAL; > > + > /* ensure minimal alignment required by mm core */ > alignment = PAGE_SIZE << > max_t(unsigned long, MAX_ORDER - 1, pageblock_order); > @@ -192,12 +192,17 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, > if (ALIGN(base, alignment) != base || ALIGN(size, alignment) != size) > return -EINVAL; > > + cma = memblock_alloc(sizeof(struct cma), sizeof(long)); > + if (!cma) { > + pr_err("Unable to allocate CMA descriptor!\n"); > + return -ENOSPC; > + } > + list_add_tail(&cma->areas, &cma_areas); > + > /* > * Each reserved area must be initialised later, when more kernel > * subsystems (like slab allocator) are available. > */ > - cma = &cma_areas[cma_area_count]; > - > if (name) > snprintf(cma->name, CMA_MAX_NAME, name); > else > @@ -253,11 +258,6 @@ int __init cma_declare_contiguous_nid(phys_addr_t base, > pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n", > __func__, &size, &base, &limit, &alignment); > > - if (cma_area_count == ARRAY_SIZE(cma_areas)) { > - pr_err("Not enough slots for CMA reserved regions!\n"); > - return -ENOSPC; > - } > - > if (!size) > return -EINVAL; > > @@ -530,10 +530,10 @@ bool cma_release(struct cma *cma, const struct page *pages, unsigned int count) > > int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data) > { > - int i; > + struct cma *c; > > - for (i = 0; i < cma_area_count; i++) { > - int ret = it(&cma_areas[i], data); > + list_for_each_entry(c, &cma_areas, areas) { > + int ret = it(c, data); > > if (ret) > return ret; > diff --git a/mm/cma.h b/mm/cma.h > index 42ae082cb067..fed800b63819 100644 > --- a/mm/cma.h > +++ b/mm/cma.h > @@ -15,11 +15,11 @@ struct cma { > spinlock_t mem_head_lock; > struct debugfs_u32_array dfs_bitmap; > #endif > + struct list_head areas; > char name[CMA_MAX_NAME]; > }; > > -extern struct cma cma_areas[MAX_CMA_AREAS]; > -extern unsigned cma_area_count; > +extern struct list_head cma_areas; > > static inline unsigned long cma_bitmap_maxno(struct cma *cma) > { > diff --git a/mm/cma_debug.c b/mm/cma_debug.c > index d5bf8aa34fdc..c39695d50224 100644 > --- a/mm/cma_debug.c > +++ b/mm/cma_debug.c > @@ -188,12 +188,12 @@ static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry) > static int __init cma_debugfs_init(void) > { > struct dentry *cma_debugfs_root; > - int i; > + struct cma *c; > > cma_debugfs_root = debugfs_create_dir("cma", NULL); > > - for (i = 0; i < cma_area_count; i++) > - cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root); > + list_for_each_entry(c, &cma_areas, areas) > + cma_debugfs_add_one(c, cma_debugfs_root); > > return 0; > } > -- > 2.25.4 >